75 results on '"Paz GF"'
Search Results
2. First report of a cat (Felis catus) infected by Leishmania (Viannia) guyanensis from Southeastern Brazil.
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Garcia TS, Ribeiro VM, Martins ALM, Freire MA, de Oliveira FCB, Lima ACVMDR, Pivari ID, Dutra-Rêgo F, Carvalho GML, Estevam LGTM, and Paz GF
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- Animals, Cats, Brazil, Male, Cat Diseases parasitology, Cat Diseases diagnosis, Leishmania guyanensis isolation & purification, Leishmania guyanensis genetics
- Abstract
Feline leishmaniasis is increasingly recognized as a disease affecting cats worldwide, with notable prevalence in regions surrounding the Mediterranean Basin and in Brazil. An approximately one-year-old domestic shorthair cat was presented with small papules and nodules (2 mm) on the nasal planum. Physical examination and routine blood analyses were normal. The cat tested negative for FIV and FeLV. Skin biopsies of the lesions were conducted, removing the nodules entirely due to their small size. The samples were submitted for histopathological and molecular analysis. Histopathology confirmed the presence of Leishmania amastigotes, while PCR-RFLP and Sanger sequencing of the hsp70 gene identified the infecting species as Leishmania guyanensis. The patient has since been under continuous clinical monitoring every six months, with no recurrence observed to date. This is the first documented case of L. guyanensis infection in a domestic cat, underscoring the need for improved diagnostic accuracy and a broader understanding of feline leishmaniasis., Competing Interests: Declarations. Ethical approval and consent to participate: No approval from research ethics committees was required for this study because the procedures were conducted using samples kindly provided by a private veterinary clinic (Bem Cuidar). Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2025. The Author(s), under exclusive licence to Springer Nature B.V.)
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- 2025
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3. Development of quantitative PCR and digital PCR for the quantification of Leishmania infantum in dogs.
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Pereira DCA, Teixeira-Neto RG, Lopes VV, Pena HP, Paz GF, Custodio CHX, Belo VS, da Fonseca Júnior AA, and da Silva ES
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Leishmaniasis is a zoonotic disease with worldwide distribution. In the Americas, the causative agent of the visceral form is the protozoa Leishmania (Leishmania) infantum. Transmission to the host or vertebrate reservoir occurs through the bite of infected arthropod females like Lutzomyia longipalpis. The epidemiological connection between the infection in dogs and humans generate constant studies about the relationship between the parasite and the canine host, including the development of methods and tests for the detection and quantification ofLeishmania (L.) infantum. Both conventional PCR (cPCR) and quantitative PCR (qPCR) can be used in the diagnosis of the parasite. Dropet Digital PCR (ddPCR) is another useful tool. Knowing the parasite load and its relationship with the clinical signs of naturally infected dogs is useful in research development and for establishing treatments that reduce the transmission of the disease. In this study, thirty-nine clinical samples of spleen from dogs naturaly infected by L. infantum were collected after necropsy. Two molecular tools were used to quantify the parasite load (qPCR and ddPCR) and there was 100% agreement in the results of the them. The tools developed in this work are important for the detection of L. infantum in dogs and humans. Droplet Digital PCR does not require a standard curve and is easy to standardize. In such manner, this new tool can generate more in-depth information in the broad debate about parasitic loads and the pathogenesis of leishmaniasis., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)
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- 2023
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4. Report of the presence of Leishmania infantum in the milk of a naturally infected female dog in Brazil.
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Ribeiro VM, Júnior DMG, Ottino J, Valle GR, de Miranda Estevam LGT, de Carvalho OV, and Paz GF
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- Dogs, Female, Animals, Milk, Brazil, Lactation, Leishmania infantum genetics, Leishmaniasis, Visceral veterinary, Dog Diseases
- Abstract
Dogs are the most important reservoir of Leishmania infantum, the causal agent of visceral leishmaniasis in Brazil. Although lymphoid tissue is the most important biological tissue where amastigotes can be found, this paper describes the presence of L. infantum DNA in the milk of a lactating naturally infected female dog. This finding suggests the need for further studies to elucidate whether breastfeeding can be a route of infection., Competing Interests: Declaration of Competing Interest The authors declare no conflicts of interest related to the study., (Copyright © 2022 Elsevier B.V. All rights reserved.)
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- 2022
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5. Sand fly bioecological aspects and risk mapping of leishmaniasis by geographical information systems approach in a mineral exploration area of Brazil.
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Carvalho GML, Silva DF, Xavier LDA, Soares JVR, Ramos VDV, Madureira AP, Lima MA, Tonelli GB, Paz GF, Rêgo FD, Andrade-Filho JD, and Margonari C
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- Animals, Brazil epidemiology, DNA, Dogs, Female, Geographic Information Systems, Insect Vectors genetics, Male, Minerals, Leishmaniasis epidemiology, Phlebotomus genetics, Psychodidae genetics
- Abstract
Epidemiological studies of leishmaniasis in areas of great human influence and environmental change serve as important tools for the implementation of effective control plans. Mining is currently a major economic activity in Brazil with the municipality of Pains, in the state of Minas Gerais, being one of the main lime producing municipalities in the country. This study aimed to map areas of potential transmission risks within the municipality of Pains using an epidemiological approach in association with the ecological study of sand flies. Twelve samplings carried out between May 2015 and April 2016 collected a total of 12,728 sandflies, comprising 2,854 females (22.42%) and 9,874 males (77.58%), of 20 species belonging to ten genera. The most abundant species was Lutzomyia longipalpis (80%). Leishmania DNA was detected in seven pools of female sand flies with an infection rate of 0.37%. Geoprocessing and the use of maps revealed that vector sand flies are distributed throughout the urban area, as are cases of canine and human leishmaniasis. However, the greatest abundances of sand flies were at sampling points at the border of the urban area. Higher densities of sand flies and the presence of Leishmania DNA may be correlated with extensive degradation by limestone mining. Integrated and multidisciplinary research approaches are necessary to better understand how the impacts of environmental change influence these insect vectors of leishmaniasis., (Copyright © 2022 Elsevier B.V. All rights reserved.)
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- 2022
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6. Leishmania infantum infection rate in dogs housed in open-admission shelters is higher than of domiciled dogs in an endemic area of canine visceral leishmaniasis. Epidemiological implications.
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Estevam LGTM, Veloso LB, Silva GG, Mori CC, Franco PF, Lima ACVMR, Ássimos GR, Reis IA, Andrade-Filho JD, Araújo MSS, Ribeiro VM, Almeida APMM, and Paz GF
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- Animals, Brazil epidemiology, Dogs, Polymerase Chain Reaction veterinary, Polymorphism, Restriction Fragment Length, Dog Diseases parasitology, Leishmania infantum genetics, Leishmaniasis, Visceral diagnosis, Leishmaniasis, Visceral epidemiology, Leishmaniasis, Visceral veterinary
- Abstract
Canine visceral leishmaniasis (CVL) is caused by Leishmania infantum and is endemic in many areas of southeastern Brazil. We have hypothesized that the prevalence of infection by L. infantum in dogs housed in open-admission animal shelters is beyond the range of 3.4 - 9.6% reported among dogs domiciled in similar CVL-endemic areas. Hence, this study aimed to determine the rate of L. infantum infection among dogs maintained in shelters and to investigate the epidemiology of CVL in such environments by analyzing hematological and biochemical parameters. A total of 627 dogs from 17 different shelters across the State of Minas Gerais were screened using the Dual-Path Platform test and enzyme-linked immunosorbent assay and 211 (33.6%) were found to be seropositive in both tests. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was performed on skin, bone marrow and lymphoid tissues of 118 seropositive dogs with inconclusive CVL clinical diagnosis and, of these, 78 (66.1%) were PCR+ for L. infantum and 7 (5.9%) were PCR+ for L. amazonensis. One dog presented a PCR-RFLP profile that was consistent with co-infection by both parasites. Leishmania amazonensis DNA was detected in skin samples of six single-infected dogs and this constitutes a novel finding. Dogs infected only with L. amazonensis were less debilitated than those infected by L. infantum, which showed typical clinical manifestations of CVL. The co-infected dog showed only mild clinical signs. The results presented herein not only support our original hypothesis but also suggest that dogs are potential reservoirs of L. amazonensis. Public health authorities should acknowledge their responsibility towards animals in collective shelters, recognize that they are potential foci of zoonotic diseases, and establish proper functioning directives to minimize transmission to humans and to other dogs., (Copyright © 2022 Elsevier B.V. All rights reserved.)
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- 2022
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7. Absence of yellow fever virus circulation in wildlife rodents from Brazil.
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de Oliveira Figueiredo P, Stoffella-Dutra AG, Costa GB, de Oliveira JS, Amaral CD, Alves PA, Filho JDA, Paz GF, Tonelli GB, Kroon EG, Drumond BP, Paglia AP, de Oliveira DB, and de Souza Trindade G
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- Animals, Animals, Wild, Brazil epidemiology, Mosquito Vectors, Retrospective Studies, Rodentia, Yellow fever virus genetics, Culicidae, Yellow Fever epidemiology, Yellow Fever veterinary
- Abstract
Yellow fever (YF), caused by the yellow fever virus (YFV), is an emerging viral zoonosis that affects humans and non-human primates (NHP). In South America, YF is naturally maintained through enzootic/sylvatic cycles involving NHPs and mosquitoes (Haemagogus and Sabethes). In this study, we retrospectively analyzed wildlife rodents to better understand their role in a potential alternative YF sylvatic cycle. The plaque reduction neutralization test was performed to detect anti-YFV antibodies, while qPCR targeting the NS5 region of flaviviruses and standard PCR targeting the CprM region were applied to detect YFV RNA in tissue and blood samples. YFV was not evidenced in any of the tested samples. These findings provide additional information regarding sylvatic YFV and emphasize the importance of YFV surveillance in wild animals as potential reservoirs/hosts given the well-established enzootic cycle in the studied areas, mainly in the Atlantic Forest., (© 2022. The Author(s) under exclusive licence to Sociedade Brasileira de Microbiologia.)
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- 2022
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8. Phase II validation study of the rK39 ELISA prototype for the diagnosis of canine visceral leishmaniasis in Brazil.
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Medeiros FAC, Souza Filho JA, Barbosa JR, Donato LE, Figueiredo FB, Werneck GL, Paz GF, Thompson M, and Marcelino AP
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- Animals, Dogs, Brazil, Enzyme-Linked Immunosorbent Assay, Sensitivity and Specificity, Dog Diseases diagnosis, Leishmania infantum, Leishmaniasis, Visceral diagnosis, Leishmaniasis, Visceral veterinary
- Abstract
Dogs are the main reservoirs in the domestic transmission cycle of visceral leishmaniasis, and the diagnosis is essential for the effectiveness of the control measures recommended by the Brazilian Ministry of Health. We assessed the diagnostic performance of the ELISA-Vetlisa/BIOCLIN prototype with serum samples from 200 dogs, in triplicate, including symptomatic, oligosymptomatic, asymptomatic, and healthy dogs, originated by two distinct panels (A and B) characterized by parasitological tests as the reference standard. In this study, the prototype kit showed a 99% sensitivity (95%CI: 94.5-100.0) and a 100% specificity (95%CI: 96.4-100.0). The sensitivity of the prototype kit did not vary significantly with the clinical status of the dogs. Considering the final result classification (positive or negative), agreement between the results of repeated tests was almost perfect (kappa = 0.99; 95%CI: 0.98-1.00). ELISA-Vetlisa/BIOCLIN is a promising option for the serological diagnosis of canine visceral leishmaniasis in Brazil.
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- 2021
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9. Correlations between tissue parasite load and common clinical signs in dogs naturally infected by Leishmania infantum.
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Chagas ÚMR, de Avelar DM, Marcelino AP, Paz GF, and Gontijo CMF
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- Animals, Dog Diseases parasitology, Dogs, Leishmania infantum, Leishmaniasis, Visceral parasitology, Leishmaniasis, Visceral pathology, Parasite Load, Skin parasitology, Dog Diseases pathology, Leishmaniasis, Visceral veterinary
- Abstract
qPCR is being used for the quantification of parasite load in different tissues of dogs infected by Leishmania infantum with or without clinical manifestations. It may be employed in the diagnosis, monitoring of the infection during treatment, and clinical studies for validation of vaccines. Aimed at enhancing the molecular diagnosis and the subsequent monitoring of the infection, this study evaluated the parasite load in several tissues from dogs infected by Leishmania infantum, showing different clinical status. Thus, the qPCR was performed on skin, conjunctival swab, popliteal lymph node, and bone marrow puncture samples taken from 65 dogs naturally infected by L. infantum. Dogs were divided into three groups per clinical score: group 1 (n = 12), included animals with zero points and no clinical manifestations of the disease; group 2 (n = 35), included animals with a score ranging from 1 to 5 points and moderate clinical manifestations; and group 3 (n = 18), included dogs with a score ranging from 6 to 11 points and intensive clinical manifestations. Another analysis was performed classifying the animals into two groups, considering the presence of, or lack of clinical signs of the disease. Analyses of these results showed that the skin was the tissue with a higher parasite load, followed by popliteal lymph node and bone marrow punctures, and conjunctival swab samples having the lowest loads. Furthermore, the skin was also the tissue with the highest parasite load when evaluating the groups individually. Animals in group 3, with intensive clinical manifestations, showed a higher parasite load in different tissues when compared to animals from groups 1 and 2. Finally, animals with clinical manifestations of the disease showed a higher parasite load when compared to dogs with no manifestations. The importance of the dog as a reservoir of L. infantum in nature is reinforced by the demonstration of skin having the highest amount of parasites/μL in this study's analysis, as well as the fact that skin is the main point of access to the parasite vector. Also, a strong and positive correlation between the intensity of clinical manifestations and the increase of parasite load in the skin was observed. In conclusion, skin was the tissue that was demonstrated to be the best option for the molecular diagnosis of L. infantum infection in dogs with varying clinical statuses used in this study., (Copyright © 2021 Elsevier B.V. All rights reserved.)
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- 2021
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10. Comparative PCR-based diagnosis for the detection of Leishmania infantum in naturally infected dogs.
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Marcelino AP, Filho JAS, E Bastos CV, Ribeiro SR, Medeiros FAC, Reis IA, Lima ACVMDR, Barbosa JR, Paz GF, and Gontijo CMF
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- Animals, DNA, Kinetoplast genetics, Female, Leishmania infantum genetics, Male, Dog Diseases diagnosis, Dogs parasitology, Leishmania infantum isolation & purification, Leishmaniasis, Visceral veterinary, Polymerase Chain Reaction methods
- Abstract
The applicability of molecular biology/PCR for canine visceral leishmaniasis diagnosis presents challenges, mainly due to the diversity of targets described. The objectives of this study were to compare the sensitivities and reliability of five targets (kDNA/120, kDNA/145, ITS1, hsp70/234 and hsp70/1300) in four different tissue samples (bone marrow, popliteal lymph node, skin and conjunctival swab). Sixty-five dogs (32 males and 33 females) naturally infected with Leishmania infantum and ten dogs without infection were examined. Dogs were characterized by serological and parasitological methods. The parasitological test was considered the gold standard for analysis. All tests presented high specificity 100% (95% CI 0.72-1), and variable sensitivity. The targets kDNA/145, ITS1, kDNA/120, hsp70/234 and hsp70/1300 detected 100% (65/65), 93.4% (61/65), 92.3% (60/65), 84.61% (55/65) and 72.3% (77/65) of positive animals respectively. The performance of PCR methods was analyzed in two different scenarios. The highest sensitivity value identified in all scenarios studied was kDNA/145. Our results suggest that popliteal lymph node and conjunctival swab samples, besides being less invasive collections, represent a good substratum for PCR-based diagnosis, and the target kDNA/145 is the best choice for detecting L. infantum DNA in naturally infected dogs., Competing Interests: Declaration of Competing Interest The authors declare that they have no conflict of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)
- Published
- 2020
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11. Diversity of phlebotomine sand flies and molecular detection of trypanosomatids in Brumadinho, Minas Gerais, Brazil.
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Tanure A, Rêgo FD, Tonelli GB, Campos AM, Shimabukuro PHF, Gontijo CMF, Paz GF, and Andrade-Filho JD
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- Animals, Brazil epidemiology, DNA, Protozoan isolation & purification, Endemic Diseases prevention & control, Female, Humans, Leishmania genetics, Leishmaniasis epidemiology, Leishmaniasis parasitology, Leishmaniasis prevention & control, Leishmaniasis transmission, Sequence Analysis, DNA, Biodiversity, Insect Vectors parasitology, Leishmania isolation & purification, Phlebotomus parasitology, Psychodidae parasitology
- Abstract
This study aimed to describe the sand fly fauna and detect trypanosomatids in these insects from Casa Branca, state of Minas Gerais, Brazil, an endemic area of both visceral (VL) and tegumentary leishmaniasis (TL). Sand flies were collected bimonthly from May 2013 to July 2014, using automatic light traps exposed for three consecutive nights in peridomiciliary areas of nine houses with previous reports of VL and TL. ITS1-PCR and DNA sequencing were performed for trypanosomatids identification. A total of 16,771 sand flies were collected belonging to 23 species. The most abundant species was Nyssomyia whitmani (Antunes & Coutinho, 1939) (70.9%), followed by Lutzomyia longipalpis (Lutz & Neiva, 1912) (15.2%) and Migonemyia migonei (França, 1920) (9.1%). Leishmania amazonensis DNA was detected in Ny. whitmani (four pools) and Le. braziliensis DNA was detected in Psychodopygus lloydi (one pool). In seven pools of Ny. whitmani and in one pool of Lu. longipalpis positive for Leishmania DNA, the parasite species was not determined due to the low quality of the sequences. Moreover, DNA of Herpetomonas spp. was detected in Ny. whitmani (two pools) and Cortelezzii complex (one pool). DNA of Crithidia spp. was detected in Ny. whitmani and Ps. lloydi (both one pool). Our results suggest that Ny. whitmani may be involved in the transmission of Le. amazonensis in the study area. The molecular detection of Le. amazonensis suggests the presence of this species in a sylvatic cycle between vertebrate and invertebrate hosts in the region of Casa Branca. Our data also reveal the occurrence of other non-Leishmania trypanosomatids in sand flies in Casa Branca District., Competing Interests: The authors have declared that no competing interests exist.
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- 2020
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12. Visceral leishmaniasis: a practical strategy for quantitative molecular diagnosis in naturally infected dogs.
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Caldas S, Marcelino AP, Faria G, de Oliveira Silva F, Ataide ACZ, Cunha LM, Bahia MT, Paz GF, and Gontijo CMF
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- Animals, Bone Marrow parasitology, DNA, Kinetoplast genetics, Dog Diseases parasitology, Dogs, Leishmaniasis, Visceral parasitology, Lymph Nodes parasitology, Molecular Diagnostic Techniques methods, Real-Time Polymerase Chain Reaction veterinary, Sensitivity and Specificity, Spleen parasitology, Dog Diseases diagnosis, Leishmania infantum genetics, Leishmaniasis, Visceral diagnosis, Leishmaniasis, Visceral veterinary, Real-Time Polymerase Chain Reaction methods
- Abstract
The diagnosis of canine visceral leishmaniasis (CVL) has been a problem for public health services due to the variety of clinical signs similar to other diseases and low sensitivity and specificity of available tests. In this sense, our main objective was to develop a simple, rapid, and accurate quantitative real-time PCR (qPCR) diagnosis for CVL. Thus, low-invasive samples from bone marrow (BM), popliteal lymph nodes (PLN), and conjunctival swabs (CS) were selected from negative and VL-positive dogs, using as gold standard, immunological and parasitological tests performed with different tissues. Oligonucleotides for Leishmania infantum kDNA were designed and the limit of quantification and amplification efficiency of the qPCR were determined using tissue-specific standards produced with DNA from those different tissues, mixed with DNA from a known amount of L. infantum promastigotes. Endogenous control was used to validate a comparative Ct method, and tissue parasite concentrations were estimated by comparison with tissue-specific reference standard samples. The overall analysis of the qPCR data suggests the following ranking for tissue choice: PLN > BM > CS. Finally, we have concluded that this molecular approach simplifies and accelerates the quantitative diagnostic process because it is easy to perform, requiring no DNA dosing or standard curve application, and it shows good diagnostic parameters, especially when using popliteal lymph node samples.
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- 2020
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13. Performance of different serological tests in the diagnosis of natural infection by Leishmania infantum in dogs.
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Ribeiro VM, Miranda JB, Marcelino AP, de Andrade HM, Reis IA, Cardoso MS, Gontijo CMF, and Paz GF
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- Animals, Dog Diseases diagnosis, Dog Diseases parasitology, Dogs, Leishmaniasis, Visceral blood, Leishmaniasis, Visceral diagnosis, Sensitivity and Specificity, Dog Diseases blood, Leishmania infantum, Leishmaniasis, Visceral veterinary, Serologic Tests veterinary
- Abstract
Visceral leishmaniasis (VL) is a zoonosis caused by the parasite Leishmania infantum and the dog is its main reservoir in rural and urban areas. The diagnosis of infection is mainly based on the presence of anti-Leishmania IgG antibodies in the serum of infected dogs. In this study, the sensitivity and specificity of qualitative rapid tests (RTs) dual path platform (DPP) Bio-Manguinhos, rapid enzyme-linked immunosorbent assay (ELISA) IDEXX, Kalazar Detect and ALERE, as well as quantitative ELISA Bio-Manguinhos and in-house indirect immunofluorescence assay (IFA) tests were analyzed in sera from infected and uninfected dogs. Serial dilutions of the in-house IFA were compared with RTs and ELISA Bio-Manguinhos. The results showed that none of the tests reached 100% sensitivity and specificity. There was no statistical difference between the analyzed RTs. The most sensitive test was the DPP Bio-Manguinhos (97.9%), while the rapid ELISA IDEXX showed higher specificity (100%). In the treatment setting of infected and/or diseased animals, quantitative tests for monitoring the evolution of antibody titers are required, which indicates the maintenance of in-house IFA in animal handling. Furthermore, we demonstrate that the RTs present higher sensitivity in serum samples with superior antibody titers obtained in the in-house IFA. However, the RTs exhibited false negatives in samples with low titers of antibodies. Among the RTs, only the DPP Bio-Manguinhos presented better performance in this situation. Therefore, the use of RTs for the diagnosis of VL in dogs with low titers of antibodies, such as asymptomatic, should be carefully evaluated., (Copyright © 2019. Published by Elsevier B.V.)
- Published
- 2019
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14. Serological, molecular, and microscopic detection of Leishmania in cats (Felis catus) in Belo Horizonte, Minas Gerais State, Brazil.
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Coura FM, Passos SKP, Pelegrino MOF, Leme FOP, Paz GF, Gontijo CMF, and Costa-Val APD
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- Animals, Brazil epidemiology, Cat Diseases diagnosis, Cat Diseases epidemiology, Cats, Endemic Diseases, Fluorescent Antibody Technique, Leishmaniasis, Visceral diagnosis, Leishmaniasis, Visceral epidemiology, Cat Diseases parasitology, Leishmania infantum immunology, Leishmaniasis, Visceral veterinary
- Abstract
The role of cats in the epidemiological cycle of leishmaniasis remains unclear. To better understand the occurrence of leishmaniasis in cats, we studied the frequency of Leishmania in serum samples of 100 cats living in an endemic region for canine and human leishmaniasis by serological, parasitological, and molecular methods. Of the 100 cats, 54 were seropositive for Leishmania antibodies by immunofluorescence antibody test. None of the bone marrow aspirates collected from these cats tested positive for the parasite in culture or upon polymerase chain reaction (PCR) analysis. Biopsy samples of the ears also tested negative for Leishmania upon PCR analysis. These findings may indicate that the region is endemic for canine leishmaniasis and cats are infected by Leishmania; or that cross-reaction with antibodies against other parasites increases the frequency of seropositivity; or that cats respond to Leishmania infection by producing antibodies when few or no parasites are present in bone marrow and tissue samples. Overall, our results suggest that cats can be infected by Leishmania ; however, we failed to demonstrate feline parasitosis. These findings highlight the need to study leishmaniasis in cats, since sandflies feed on cats, these animals may act as a reservoir for the parasite.
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- 2018
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15. IgG avidity index and complete blood count as biomarkers of clinical disease in naturally infected dogs with Leishmania infantum.
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Lopes VV, Belo VS, Pereira DA, Coelho MB, Pena HP, Alves NR, de Carvalho Júnior CG, Werneck GL, Paz GF, de Azambuja Ribeiro RIM, da Silva ES, and Teixeira-Neto RG
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- Animals, Biomarkers analysis, Dog Diseases parasitology, Dogs, Leishmaniasis, Visceral diagnosis, Leishmaniasis, Visceral parasitology, Logistic Models, Multivariate Analysis, Blood Cell Count veterinary, Dog Diseases diagnosis, Leishmania infantum isolation & purification, Leishmaniasis, Visceral veterinary
- Abstract
Canine visceral leishmaniosis (CVL), a parasitic disease caused by Leishmania infantum, may evolve to a chronic condition and lead to death. Evaluation of infected dogs is important to establish the clinical and laboratory parameters involved in the evolution of the disease. The objectives of the present study were to discriminate a canine population (n = 52) into sub-clinical and clinically affected dogs based on signs and scores, to evaluate the hematological, biochemical, histopathological and parasitological parameters of the two dog groups, and to analyze the results by multivariate regression analysis with the aim of establishing biomarkers of CVL clinical disease. The most common signs observed in the clinically affected dogs (n = 29) were hyperkeratosis, weight loss, onychogryphosis, pale mucosa and lymphadenomegaly. In the multivariate analysis, animals presenting high IgG avidity index and low red blood, lymphocyte and eosinophil counts, and low serum urea concentration had an increased probability of being classified as clinically affected (p < 0.05). All five parameters were considered to be strong biomarkers for monitoring the clinical disease, while IgG avidity percentage was strongly correlated with the number of clinical signs and could function as an indicator of the duration of infection. This is the first report on the application of IgG avidity and of multivariate regression analysis in establishing associations between the clinical signs of CVL and host biomarkers. Since avidity index (AI) percentages were strongly correlated with the number of clinical signs, it could be useful in clinical practice for auxiliary diagnosis of CVL and monitoring disease progression. A limitation of this study is the lack of information on co-infections by Anaplasma platys, Babesia canis vogeli, Ehrlichia canis and Hepatozoon canis. Therefore future studies should evaluate the influence of such co-infections on the associations studied using multivariate methods with larger samples., (Copyright © 2018 Elsevier B.V. All rights reserved.)
- Published
- 2018
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16. Implications of the use of serological and molecular methods to detect infection by Leishmania spp. in urban pet dogs.
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Paz GF, Rugani JMN, Marcelino AP, and Gontijo CMF
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- Animals, Brazil epidemiology, Dogs, Leishmania genetics, Leishmaniasis diagnosis, Pets, Polymerase Chain Reaction, Serologic Tests, Dog Diseases diagnosis, Leishmaniasis veterinary
- Abstract
The aim of this study was to evaluate the relationship between naturally occurring Leishmania spp. infections in dogs (Canis familiaris) and the practical implications of the use of serological and molecular methods to confirm diagnoses. The study population consisted of 96 domestic dogs in southeastern Brazil. Serum samples were tested for the presence of anti-Leishmania immunoglobulin G (IgG) antibodies using four commercial canine visceral leishmaniasis kits. Dogs confirmed positive by immunofluorescence antibody test (IFAT) were culled and samples from mesenteric lymph nodes, spleen border, bone marrow and ear skin were taken and submitted to DNA extraction. PCR reactions were performed using primers that amplify a 300-350 bp fragment of the Leishmania ribosomal internal transcribed spacer 1 (ITS1) region. The ITS1 amplified products were analyzed by PCR-RFLP using Hae III restriction endonuclease. To confirm the Leishmania species detected by PCR, each purified sample was sequenced in duplicate. Of the 96 serum samples submitted to serological assays, 8 (8.3%) tested positive for Leishmania by IFAT, 4 (4.1%) by ELISA, 2 (2.1%) by rK39 RDT and 7 (7.3%) by DPP. Four of these infected dogs (50%) were found to be infected only by Leishmania braziliensis or Leishmania amazonensis, and their serum samples tested positive by IFAT and DPP. These findings demonstrate for the first time that cross-reactivity of L. braziliensis and L. amazonensis infection in dogs can be found using the DPP serum test. This is the first record of Leishmania (Leishmania) amazonensis confirmed by a specific molecular marker in dogs (Canis familiaris) from Belo Horizonte, Brazil., (Copyright © 2018 Elsevier B.V. All rights reserved.)
- Published
- 2018
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17. Leishmania (Viannia) braziliensis infection in wild small mammals in ecotourism area of Brazil.
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Tonelli GB, Tanure A, Rego FD, Carvalho GML, Stumpp R, Ássimos GR, Campos AM, Lima ACVMDR, Gontijo CMF, Paz GF, and Andrade Filho JD
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- Animals, Brazil epidemiology, Leishmania braziliensis isolation & purification, Mammals parasitology
- Abstract
Leishmaniases are parasitic diseases transmitted to mammalian hosts by sand fly vectors (Diptera: Psychodidae). Despite the increasing occurrence of visceral and cutaneous leishmaniasis cases in urban centers, their transmission still occur primarily in wild environments and may be associated with professional activities and recreation, such as ecotourism. The Reserva Particular do Patrimônio Natural Santuário do Caraça (RPPNSC) is one of the largest ecotourism attractions in the State of Minas Gerais, Brazil, and comprises an area of environmental preservation with 11,233 hectares presenting a transitional vegetation between Cerrado and Atlantic Forest. The present study describes the abundance of small mammals in RPPNSC, the isolation and identification of Leishmania in five wild animals. Small mammals were bimonthly trapped along 6 trails within the RPPNSC with 10 Tomahawk traps each. Two trails were located in peridomiciliary areas near tourist lodging facilities, and four trails were located at sites visited by tourists in forest areas. The most prevalent species were Akodon cursor, Cerradomys subflavus and Oligoryzomys nigripes. Six isolates of Leishmania were obtained from these animals and identified as Leishmania braziliensis through HSP70-PCR RFLP method. Leishmania spp. DNA was detected by kDNA-PCR method and isolated by biphasic culture. Studies point to some of the captured species as potential wild reservoirs of Leishmania, suggesting they may be involved in the transmission cycle in these wild environments.
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- 2017
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18. Detection of Leishmania spp in silvatic mammals and isolation of Leishmania (Viannia) braziliensis from Rattus rattus in an endemic area for leishmaniasis in Minas Gerais State, Brazil.
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Pereira AAS, Ferreira EC, Lima ACVMDR, Tonelli GB, Rêgo FD, Paglia AP, Andrade-Filho JD, Paz GF, and Gontijo CMF
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- Animals, Brazil epidemiology, HSP70 Heat-Shock Proteins metabolism, Polymerase Chain Reaction, Polymorphism, Restriction Fragment Length, Rats, Leishmania braziliensis isolation & purification, Leishmaniasis, Cutaneous epidemiology, Leishmaniasis, Cutaneous parasitology, Mammals parasitology, Rodent Diseases epidemiology, Rodent Diseases parasitology
- Abstract
Knowledge of potential reservoirs of Leishmania spp. in an anthropic environment is important so that surveillance and control measures can be implemented. The aim of this study was to investigate the infection by Leishmania in small mammals in an area located in Minas Gerais, Brazil, that undergoes changes in its natural environment and presents autochthonous human cases of cutaneous leishmaniasis (CL) and visceral leishmaniasis (VL). For the capture of the animals, Sherman and Tomahawk traps were used and distributed in the peridomicile of houses with reports of autochthonous cases of CL or VL. Six catches were carried out on two consecutive nights with intervals of two months during one year and samples of spleen, liver, tail skin, ear skin and bone marrow of the animals were obtained. Parasitological and molecular methods were used to detect the infection. Identification of the Leishmania species was performed by PCR RFLPhsp70. Twenty five animals of four species were captured: ten Rattus rattus, nine Didelphis albiventris, five Cerradomys subflavus and one Marmosops incanus. In the PCR-hsp70, five animals were positive (20%). The Leishmania species identified in PCR-RFLPhsp70 were: Leishmania braziliensis in D. albiventris (2), C. subflavus (1) and R. rattus (1) and Leishmania infantum in R. rattus (1). The highest positivity rate for L. braziliensis was obtained in the liver samples. The spleen was the only tissue positive for L. infantum. It was isolated in culture medium L. braziliensis from two samples (liver and spleen) of R. rattus. This is the first record of isolation of L. braziliensis from R. rattus in the southeastern region of Brazil. These results are relevant to the knowledge of the epidemiology of leishmaniasis in the region, mainly in the investigation of the presence of hosts and possible reservoirs of the parasite.
- Published
- 2017
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19. Reliability of techniques used in the diagnosis of canine visceral leishmaniasis by the national control program in Brazil: A survey in an area of recent transmission.
- Author
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Belo VS, Gregório EA, Teixeira-Neto RG, da Rocha Lima ACVM, Pereira AAS, Marcelino AP, Paz GF, and da Silva ES
- Subjects
- Animals, Antibodies, Protozoan blood, Brazil epidemiology, Communicable Disease Control methods, Dog Diseases epidemiology, Dogs, Enzyme-Linked Immunosorbent Assay standards, Female, Immunoassay methods, Immunoassay standards, Leishmania infantum, Leishmaniasis, Visceral blood, Leishmaniasis, Visceral epidemiology, Male, Reproducibility of Results, Sensitivity and Specificity, Seroconversion, Seroepidemiologic Studies, Dog Diseases blood, Dog Diseases parasitology, Enzyme-Linked Immunosorbent Assay veterinary, Immunoassay veterinary, Leishmaniasis, Visceral veterinary
- Abstract
One of the key components of the Brazilian Program for the Control of Visceral Leishmaniasis (PCLV) is the euthanasia of Leishmania-infected canine reservoirs, the detection of which depends on a screening procedure involving a Dual Path Platform
® (DPP) immunoassay and a confirmatory enzyme-linked immunosorbent assay (ELISA). The aims of the present study were to evaluate the reliability of these techniques in a region of recent transmission of canine VL, to follow up the seroconversion 3-4 months after the initial diagnosis of DPP reactive but ELISA indeterminate or non-reactive dogs, and to identify the species of Leishmania in circulation in the area. Each animal was submitted to DPP under field conditions, performed by municipal health workers using peripheral blood (DPP-field), to DPP under laboratory conditions using serum (DPP-lab) and to ELISA using serum. The agreements between the tests were determined using McNemar's χ2 test, Cohen's kappa coefficient (k) at the 95% confidence interval and prevalence-adjusted bias-adjusted kappa (PABAK). Of the 1130 dogs examined, 74.2% were non-reactive in all three tests applied. Based on the PCLV positive-infection criterion, seroprevalence was 8.9% (101/1130) with 83.2% (84/101) of infected animals showing reactivity in all three tests while 7.8% (8/101) were reactive in DPP-field and ELISA and 8.9% (9/101) in DPP-lab and ELISA. The proportions of disagreements were substantial in all comparisons. Inter-rater reliability between DPP-field and ELISA (k=0.55; PABAK=0.78) and DPP-lab and ELISA (k=0.59; PABAK=0.81) were considered moderate, while that between DPP-field and DPP-lab (k=0.61; PABAK=0.79) was classified as marginally good. The proportion of seroconversions in DPP reactive animals that were initially ELISA indeterminate was significantly higher than in those that were DPP reactive but initially ELISA non-reactive. Restriction fragment length polymorphism analysis revealed the presence of Leishmania infantum, the etiologic agent of VL, in bone marrow samples from VL-infected animals. Our data showed that the techniques and protocols currently employed in the PCLV screening approach are not entirely reliable. Further consideration should be given to monitoring dogs with undetermined results in ELISA and a better training should be provided for health workers responsible for performing DPP tests applied under field conditions., (Copyright © 2017 Elsevier B.V. All rights reserved.)- Published
- 2017
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20. Bloodmeal Identification in Field-Collected Sand Flies From Casa Branca, Brazil, Using the Cytochrome b PCR Method.
- Author
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Carvalho GML, Rêgo FD, Tanure A, Silva ACP, Dias TA, Paz GF, and Andrade Filho JD
- Subjects
- Animals, Birds blood, Brazil, Female, Mammals blood, Polymerase Chain Reaction methods, Avian Proteins analysis, Cytochromes b analysis, Insect Vectors physiology, Mitochondrial Proteins analysis, Polymerase Chain Reaction veterinary, Psychodidae physiology
- Abstract
PCR-based identification of vertebrate host bloodmeals has been performed on several vectors species with success. In the present study, we used a previously published PCR protocol followed by DNA sequencing based on primers designed from multiple alignments of the mitochondrial cytochrome b gene used to identify avian and mammalian hosts of various hematophagous vectors. The amplification of a fragment encoding a 359 bp sequence of the Cyt b gene yielded recognized amplification products in 192 female sand flies (53%), from a total of 362 females analyzed. In the study area of Casa Branca, Brazil, blood-engorged female sand flies such as Lutzomyia longipalpis (Lutz & Neiva, 1912), Migonemyia migonei (França, 1924), and Nyssomyia whitmani (Antunes & Coutinho, 1939) were analyzed for bloodmeal sources. The PCR-based method identified human, dog, chicken, and domestic rat blood sources., (© The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
- Published
- 2017
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21. Isolation of Rickettsia rickettsii from the tick Amblyomma sculptum from a Brazilian spotted fever-endemic area in the Pampulha Lake region, southeastern Brazil.
- Author
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Labruna MB, Krawczak FS, Gerardi M, Binder LC, Barbieri ARM, Paz GF, Rodrigues DS, Araújo RN, Bernardes ML, and Leite RC
- Abstract
Brazilian spotted fever (BSF) is a tick-borne disease caused by the bacterium Rickettsia rickettsii, the deadliest spotted fever of the world, transmitted in southeastern Brazil mainly by the tick Amblyomma sculptum, a member of the Amblyomma cajennense species complex. In the present study, over 5000 adults of A. sculptum ticks were collected by dry ice traps in the Municipal Ecological Park, alongside the Pampulha Lake region, a BSF-endemic area of Belo Horizonte city, state of Minas Gerais, southeastern Brazil. Ticks were taken alive to the laboratory, where a sample of 2100 specimens was processed for isolation of R. rickettsii. For this purpose, ticks were macerated and intraperitoneally inoculated into guinea pigs. Only one out of 21 inoculated guinea pigs presented high fever within 21days post inoculation with tick homogenates. This febrile animal was euthanized and its internal organs were macerated and inoculated into additional guinea pigs (guinea pig passage). A spleen sample from a febrile guinea pig was used to inoculate Vero cells, resulting in a successful isolation and in vitro establishment of rickettsiae. Rickettsia-infected Vero cells were used for molecular characterization of the rickettsial isolate through PCR and DNA sequencing of fragments of three rickettsial genes (gltA, ompA, and ompB), which were all 100% identical to corresponding sequences of R. rickettsii from GenBank. The present R. rickettsii isolate was designated as strain Pampulha. A minimal infection rate of 0.05% R. rickettsii-infected ticks was estimated for A. sculptum population of the Pampulha Lake region. Our results, coupled with epidemiological evidences, suggest that R. rickettsii strain Pampulha, isolated from A. sculptum ticks in the present study, is the strain responsible for human clinical cases of BSF in the Pampulha Lake region of Belo Horizonte city., (Copyright © 2017 Elsevier B.V. All rights reserved.)
- Published
- 2017
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22. A prototype of the direct agglutination test kit (DAT-Canis) for the serological diagnosis of canine visceral leishmaniasis.
- Author
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Oliveira E, Saliba JW, Oliveira D, Dias ES, and Paz GF
- Subjects
- Animals, Antibodies, Protozoan blood, Dog Diseases blood, Dogs, Leishmaniasis, Visceral blood, Leishmaniasis, Visceral diagnosis, Sensitivity and Specificity, Agglutination Tests veterinary, Dog Diseases diagnosis, Leishmaniasis, Visceral veterinary, Serologic Tests veterinary
- Abstract
This report describes the stege I/II development of a new direct agglutination test (DAT) for the diagnosis of canine visceral leishmaniasis (CVL) using freeze-dried antigen produced Coomassie blue-stained Leishmania (Leishmania) infantum promastigotes. In stage I, 16 canine serum samples, collected from eight dogs carrying CVL and eight healthy dogs, were assessed with the DAT using 2-mercaptoethanol (2-ME), N-acetyl-cysteine (NAC), kaolin or NAC plus urea (NAC+U) to improve the assay conditions. Stage II assessed the diagnostic accuracy with 100 serum samples collected from dogs with symptomatic CVL and clinically healthy dogs, comparing the four different sample diluents. The CVL-DAT prototype kit showed equivalent performances when 2-ME, NAC or NAC+U were used: 97.1% sensitivity (CI: 83-99.8%), 97% specificity (CI: 88.5-99.5%) and a 97% diagnostic accuracy (CI: 90.8-99.2). With kaolin, a 94.1% sensitivity (CI: 79-99%), 97% specificity (CI: 88.5-99.5%) and 96% diagnostic accuracy were observed (CI: 89.5-98.7), with no statistically significant differences among the four reagents (p=1.0). The NAC plus urea in sample diluent decreased non-specific agglutination, promoted a better defined sharp-edged blue spot and was thus chosen as a component for the new DAT prototype to diagnose canine VL, designated DAT-Canis., (Copyright © 2016 Elsevier B.V. All rights reserved.)
- Published
- 2016
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23. Dynamics of Ctenocephalides felis felis (Siphonaptera: Pulicidae) Infestations on Urban Dogs in Southeastern Brazil.
- Author
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Paz GF, Avelar DM, Reis IA, and Linardi PM
- Subjects
- Animals, Brazil epidemiology, Cities, Climate, Dog Diseases parasitology, Dogs, Female, Flea Infestations epidemiology, Flea Infestations parasitology, Male, Prevalence, Seasons, Ctenocephalides physiology, Dog Diseases epidemiology, Flea Infestations veterinary
- Abstract
The cat flea, Ctenocephalides felis felis (Bouché, 1835), is an important ectoparasite of dogs and cats throughout the world, causing annoyance to the animals and acting as a vector of infections and a cause of allergic dermatitis in dogs and cats. Although climatic variability and seasonality are known to influence the diversity and abundance of fleas, few investigations of seasonal prevalence of cat flea infestation have involved the same group of dogs being examined regularly over an extended period. The aim of this study was to determine the effects of temperature, rainfall, and relative humidity on the infestation by C. felis felis on 88 outdoor dogs in southeastern Brazil. The dogs, which were of mixed breed, sex, and age, were examined for ectoparasites every month during the period August 2011 to July 2012, and samples of fleas were randomly collected and identified. Meteorological data, comprising mean temperature, total rainfall, and mean relative humidity, were recorded for the calendar month prior to that in which the examinations were performed. Dogs were found to be infested only with C. felis felis, with a higher prevalence in the months with lowest rainfall (July, August, and September). The data obtained in this investigation can be used in control programs in order to establish an efficient strategy for environmental management and the application of insecticides, particularly during the driest months of the year based on the seasonal pattern of infestation of dogs by C. felis felis., (© The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
- Published
- 2015
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24. Leishmania, Babesia and Ehrlichia in urban pet dogs: co-infection or cross-reaction in serological methods?
- Author
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Krawczak Fda S, Reis IA, Silveira JA, Avelar DM, Marcelino AP, Werneck GL, Labruna MB, and Paz GF
- Subjects
- Animals, Antibodies, Bacterial blood, Antibodies, Protozoan blood, Babesiosis diagnosis, Brazil epidemiology, Coinfection veterinary, Dog Diseases diagnosis, Dogs, Ehrlichiosis diagnosis, Ehrlichiosis epidemiology, Enzyme-Linked Immunosorbent Assay veterinary, Female, Fluorescent Antibody Technique, Indirect veterinary, Leishmaniasis diagnosis, Leishmaniasis epidemiology, Male, Urban Population, Babesiosis epidemiology, Dog Diseases epidemiology, Ehrlichiosis veterinary, Endemic Diseases veterinary, Leishmaniasis veterinary
- Abstract
Introduction: The present study was designed to assess the occurrence of co-infection or cross-reaction in the serological techniques used for detecting the anti-Leishmania spp., -Babesia canis vogeli and -Ehrlichia canis antibodies in urban dogs from an area endemic to these parasites., Methods: The serum samples from dogs were tested for the Babesia canis vogeli strain Belo Horizonte antigen and Ehrlichia canis strain São Paulo by immunofluorescence antibody test (IFAT) and by anti-Leishmania immunoglobulin G (IgG) antibody detection to assess Leishmania infection. We used the following four commercial kits for canine visceral leishmaniasis: ELISA, IFAT, Dual Path Platform (DPP) (Bio Manguinhos(r)/FIOCRUZ/MS) and a rK39 RDT (Kalazar Detect Canine Rapid Test; Inbios)., Results: Of 96 serum samples submitted to serological assays, 4 (4.2%) were positive for Leishmania as determined by ELISA; 12 (12.5%), by IFAT; 14 (14.6%) by rK39 RDT; and 20 (20.8%), by DPP. Antibodies against Ehrlichia and Babesia were detected in 23/96 (23.9%) and 30/96 (31.2%) samples, respectively. No significant association was identified between the results of tests for detecting Babesia or Ehrlichia and those for detecting Leishmania (p-value>0.05)., Conclusions: In the present study, we demonstrated co-infection with Ehrlichia or Babesia and Leishmania in dogs from Minas Gerais (Brazil); we also found that the serological tests that were used did not cross-react.
- Published
- 2015
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25. Ectoparasites and anti-Leishmania antibodies: association in an observational case-control study of dogs from a Brazilian endemic area.
- Author
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Paz GF, Reis IA, Avelar DM, da Mata Ferreira EC, and Werneck GL
- Subjects
- Animals, Antibodies, Protozoan blood, Brazil epidemiology, Case-Control Studies, Ctenocephalides physiology, Dog Diseases epidemiology, Dog Diseases parasitology, Dogs, Enzyme-Linked Immunosorbent Assay veterinary, Female, Flea Infestations epidemiology, Flea Infestations parasitology, Fluorescent Antibody Technique, Indirect veterinary, Leishmania isolation & purification, Leishmaniasis, Visceral epidemiology, Leishmaniasis, Visceral parasitology, Leishmaniasis, Visceral transmission, Male, Prevalence, Rhipicephalus sanguineus physiology, Seasons, Seroepidemiologic Studies, Tick Infestations epidemiology, Tick Infestations parasitology, Ctenocephalides parasitology, Dog Diseases transmission, Flea Infestations veterinary, Leishmaniasis, Visceral veterinary, Rhipicephalus sanguineus parasitology, Tick Infestations veterinary
- Abstract
It has been proposed that the transmission of canine visceral leishmaniasis might involve the participation of mechanical vectors, including ticks of the family Ixodidae, in particular the brown dog tick Rhipicephalus sanguineus, and the cat flea Ctenocephalides felis felis. Here, the association between the infestation by R. sanguineus and C. felis felis and the occurrence of anti-Leishmania antibodies was evaluated in an observational case-control study of dogs living in a Brazilian endemic area for canine visceral leishmaniasis. Blood samples were taken once every three months for one year from 96 initially seronegative domestic dogs, and submitted to indirect immunofluorescence antibody assay. All dogs were evaluated for the presence of ticks and fleas, and the results were expressed qualitatively as infested or non-infested, irrespective of the intensity of infestation. At the end of follow-up, twenty dogs had turned seropositive, while 68 remained seronegative and 8 were excluded because of incomplete data. All the dogs were asymptomatic. The odds of infection was significantly greater (OR=3.54, CI95%=1.10-12.53) for dogs infested by C. felis felis compared to their non-infested counterparts. In contrast, the odds of infection showed no significance difference between non-infested and R. sanguineus-infested groups of dogs (OR=0.31, CI95%=0.03-1.52). This study provides further evidence for the potential role of C. felis felis in mechanically transmitting Leishmania among the canine population., (Copyright © 2013 Elsevier B.V. All rights reserved.)
- Published
- 2013
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26. Epidemiological aspects of human and canine visceral leishmaniasis in Montes Claros, State of Minas Gerais, Brazil, between 2007 and 2009.
- Author
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Prado PF, Rocha MF, Sousa JF, Caldeira DI, Paz GF, and Dias ES
- Subjects
- Animals, Brazil epidemiology, Child, Child, Preschool, Disease Notification, Dogs, Female, Humans, Incidence, Infant, Infant, Newborn, Male, Middle Aged, Urban Population, Dog Diseases epidemiology, Leishmaniasis, Visceral epidemiology, Leishmaniasis, Visceral veterinary
- Abstract
Introduction: Visceral leishmaniasis (VL) is an expanding zoonosis in Brazil and is becoming urbanized in several Brazilian regions. This study aims to describe the epidemiological features of human and canine VL in the municipality of Montes Claros, State of Minas Gerais, by focusing on their spatial distribution., Methods: Data concerning human cases and reactive dogs for VL from 2007 to 2009 were obtained from the Information System for Disease Notification (SINAN) and from reports of the local Centro de Controle de Zoonoses (CCZ), respectively. The addresses of human and canine cases have been georeferenced and localized in thematic maps, allowing their spatial visualization as well as the identification of areas at risk of VL transmission., Results: Ninety-five cases of human VL were reported in the period. The 0-9-year-old age group (48.4%) was the most affected, within which the majority consisted of male patients (64%). Of the samples collected for the canine serological survey, 2,919 (6.3%) were reactive to VL. The spatial localization of these cases shows that the disease was scattered in the urban area of the municipality. Areas showing a higher dissemination risk were concentrated in the central, northwestern, and southern regions of the city., Conclusions: Identifying the areas most at risk in urban Montes Claros may help guide actions toward local epidemiological vigilance and control.
- Published
- 2011
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27. Eco-epidemiology of visceral leishmaniasis in the urban area of Paracatu, state of Minas Gerais, Brazil.
- Author
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Dias ES, Regina-Silva S, França-Silva JC, Paz GF, Michalsky EM, Araújo SC, Valadão JL, de Oliveira Lara-Silva F, de Oliveira FS, Pacheco RS, and Fortes-Dias CL
- Subjects
- Animals, Brazil epidemiology, Cities, Dog Diseases epidemiology, Dogs, Ecosystem, Female, Leishmania classification, Leishmaniasis, Visceral epidemiology, Male, Psychodidae, Dog Diseases parasitology, Leishmaniasis, Visceral veterinary
- Abstract
The present study was developed in the urban area of Paracatu, an endemic city for the American visceral leishmaniasis in Brazil. A six-month canine survey was performed with 6295 domiciled dogs in 28 districts in that area and showed that 4.2% of those (267 dogs) were positive for VL by ELISA and IFAT serum assays. Prevalence ratios for canine VL varied between 1.2% and 16.1%, depending on the district under investigation. Fifteen dogs - 80% of which were clinically asymptomatic for VL - were submitted to a more detailed study that comprised direct parasitological examination and Leishmania kDNA amplification of tissue samples as well as two PCR-RFLP methods using myelocultures. Leishmania amastigotes or Leishmania DNA were detected in all dogs but one. The infecting species of Leishmania was identified in about 50% (7/15) of the sample dogs: Leishmania (Leishmania) chagasi in two of them and, unexpectedly, Leishmania (Leishmania) amazonensis in the remaining five. Three months after the end of confiscation and elimination of the VL-seropositive dogs in the 28 districts of Paracatu, a systematic entomological survey was performed in five of them. Six hundred and sixty five (665) phlebotomine sand flies were captured in total, from which 89.5% were identified as Lutzomyia longipalpis. The population density of that species increased during the rainy season. Other thirteen (13) species of phlebotomine sand flies were captured at varying percentages from 0.2 to 5.0%. It is worth noting that L. longipalpis females were predominantely intradomicile when compared to males, suggesting that the VL transmission cycle in Paracatu may be occurring inside home., (Copyright © 2010 Elsevier B.V. All rights reserved.)
- Published
- 2011
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28. Phlebotomine sandflies (Diptera: Psychodidae) in Governador Valadares, a transmission area for American tegumentary leishmaniasis in State of Minas Gerais, Brazil.
- Author
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Barata RA, Paz GF, Bastos MC, Andrade RC, Barros DC, Silva FO, Michalsky EM, Pinheiro Ada C, and Dias ES
- Subjects
- Animals, Brazil, Female, Male, Population Density, Seasons, Insect Vectors classification, Leishmaniasis, Cutaneous transmission, Psychodidae classification
- Abstract
Introduction: A study on the phlebotomine sandfly fauna was carried out in an endemic area for American tegumentary leishmaniasis in the municipality of Governador Valadares, in the State of Minas Gerais, Brazil., Methods: Captures were undertaken using HP light traps in four districts, on three nights per month, for one year (from January to December 2008). Correlations between climatic factors (temperature, relative air humidity and rainfall) and the numbers of sandflies collected was observed., Results: 5,413 phlebotomine specimens were caught and were identified as belonging to 12 species. Of these specimens, 2,851 (52%) were females and 2,562 (48%) were males., Conclusions: Lutzomyia intermedia predominated (29.9% of the species caught), thus suggesting that they were responsible for transmission of American tegumentary leishmaniasis, together with L. whitmani, which was also found in the area (4.3%). The presence of L. longipalpis (11.9%), the main vector for visceral leishmaniasis in Brazil, is an important finding, which makes rigorous entomological surveillance of the area necessary.
- Published
- 2011
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29. Association between the prevalence of infestation by Rhipicephalus sanguineus and Ctenocephalides felis felis and the presence of anti-Leishmania antibodies: A case-control study in dogs from a Brazilian endemic area.
- Author
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Paz GF, Ribeiro MF, de Magalhães DF, Sathler KP, Morais MH, Fiúza VO, Brandão ST, Werneck GL, Fortes-Dias CL, and Dias ES
- Subjects
- Animals, Antibodies, Protozoan blood, Brazil, Disease Reservoirs veterinary, Dogs, Female, Flea Infestations epidemiology, Leishmania immunology, Leishmaniasis epidemiology, Male, Prevalence, Seroepidemiologic Studies, Tick Infestations epidemiology, Ctenocephalides parasitology, Dog Diseases epidemiology, Flea Infestations veterinary, Leishmaniasis veterinary, Rhipicephalus sanguineus parasitology, Tick Infestations veterinary
- Abstract
The association between the prevalence of infestation by Rhipicephalus sanguineus and Ctenocephalides felis felis and the presence of anti-Leishmania antibodies has been evaluated in dogs located in a city of Brazil endemic for canine visceral leishmaniasis. Blood samples from 5556 domestic dogs domiciliated in the urban area of Belo Horizonte (Minas Gerais state) were submitted to enzyme linked immunosorbent (ELISA) and indirect immunofluorescent antibody (IFAT) assays, and 432 (7.8%) animals tested positive. Seropositive (n=200) and seronegative (n=200) dogs were randomly selected and examined for the presence of ticks and fleas, the results of which were expressed qualitatively as infested or non-infested, irrespective of the intensity of infestation. The prevalence of infestation by R. sanguineus was significantly greater (ρ=0.04) among seropositive dogs (38.5%) compared with their seronegative counterparts (29.0%). Similarly, the prevalence of infestation by C. felis felis was significantly greater (ρ<0.01) within the seropositive group (36.5%) than within the seronegative group (15.0%). Moreover, the probability of seropositivity for Leishmania was 53% higher in tick-infested dogs and 300% higher in flea-infested dogs in comparison with non-infested animals. Our data provide evidence of the vectorial capacity of these ectoparasites in transmitting Leishmania to the canine population, although further studies are needed to confirm or reject this hypothesis., (Copyright © 2010 Elsevier B.V. All rights reserved.)
- Published
- 2010
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30. Evaluation of the vectorial capacity of Rhipicephalus sanguineus (Acari: Ixodidae) in the transmission of canine visceral leishmaniasis.
- Author
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Paz GF, Ribeiro MF, Michalsky EM, da Rocha Lima AC, França-Silva JC, Barata RA, Fortes-Dias CL, and Dias ES
- Subjects
- Animals, Dog Diseases parasitology, Dogs, Female, Leishmaniasis, Visceral transmission, Male, Ticks, Disease Vectors, Dog Diseases transmission, Leishmania isolation & purification, Leishmaniasis, Visceral veterinary, Rhipicephalus sanguineus parasitology
- Abstract
The vectorial capacity of Rhipicephalus sanguineus in the transmission of canine visceral leishmaniasis has been evaluated through a laboratory-controlled experiment. One healthy Leishmania-free dog and two dogs naturally infected with Leishmania were infested with R. sanguineus in various stages of development. Engorged larvae, unfed nymphs, engorged nymphs, unfed adults, engorged female adults and fed male adults were collected from the experimental animals and examined for Leishmania infection by optical microscopy, polymerase chain reaction (PCR) and parasite culture. Leishmania forms were not detected in any of the 433 smears prepared from engorged colonies nor in any of the 118 smears prepared from unfed colonies. However, one flagellate structure was identified in one of the smears. All pools of R. sanguineus that had fed on the infected dogs tested PCR-positive for Leishmania DNA, with the single exception of the pool of engorged larvae. In contrast, all pools of ticks that had fed on the Leishmania-free dog were PCR-negative. Leishmania growth was not observed in any of the tick colonies following incubation on culture medium. Considering that no Leishmania forms were identified in any of the meticulously analysed smears derived from engorged colonies of R. sanguineus, it appears somewhat unlikely that the maintenance and multiplication of Leishmania occurs within the tick.
- Published
- 2010
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31. [Drop off rhythm of Rhipicephalus sanguineus (Acari: Ixodidae) of artificially infested dogs].
- Author
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Paz GF, Labruna MB, and Leite RC
- Subjects
- Animals, Brazil, Circadian Rhythm, Dogs, Tick Infestations parasitology, Dog Diseases parasitology, Rhipicephalus sanguineus physiology, Tick Infestations veterinary
- Abstract
The present study evaluated the drop-off rhythm of Rhipicephalus sanguineus (Latreille) ticks from two populations from Brazil, one from Monte Negro, state of Rondônia, and another from Belo Horizonte, state of Minas Gerais. Artificial infestations with ticks were performed on dogs in the laboratory, held in a light: scotophase regimen of 12:12 h. Larval drop-off rhythm was characterized by similar number of engorged larvae detaching during both periods of light and scotophase, or by a larger number of larvae detaching during the light period. In contrast, most of the engorged nymphs and females detached from dogs during the scotophase period. These results indicate that under natural conditions, most of R. sanguineus engorged nymphs and females detach from dogs during the night period, whereas engorged larvae detach in higher proportions during daytime. Based on these data, tick control measures, encompassing environmental treatments with acaricide, should be indicated. The control measures are especially indicated in places where dogs spend or visit during the night period, since these places possibly harbor most of the free-living stages of R. Sanguineus.
- Published
- 2008
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32. [Control of Rhipicephalus sanguineus (Latrielle, 1806) (Acari: Ixodidae) in the kennel of the UFMG Veterinary School, Belo Horizonte, Minas Gerais, Brazil].
- Author
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Paz GF, Leite RC, and de Oliveira PR
- Subjects
- Animals, Brazil, Schools, Veterinary, Dogs parasitology, Insecticides, Rhipicephalus, Tick Control
- Abstract
The present work was aimed at proposing a control measure for Rhipicephalus sanguineus in a naturally infected kennel of 72 m(2) of the UFMG Veterinary School with 25 dogs of different breeds. A sensitivity test to acaricide products was applied in a sample of R. sanguineus. Out of the acaricide products tested: 12.5% Amitraz (product 1); 2% Alfamethrin and 60% Dichlorvos association (product 2); 5% Deltamethrin (product 3) and the association between 77.6% Trichlorfon, 1.0% Coumaphos and 1.0% Cyfluthrin (product 4); only 1 and 4 products showed 100% efficacy. Amitraz (12.5%) was used for controlling R. sanguineus in the surrounding of the kennel, on which four treatments every seven days were carried out in the facilities. For parasitic R. sanguineus, a single topical treatment was used: Flumetrin 1.0% pour-on on all the 25 dogs. This control measure significantly reduced the population of R. sanguineus within the kennel. A slight infestation was observed in the seventh month after treatment. A new application of 12.5% Amitraz was done in the kennel as well as a new topical treatment with Flumetrin 1.0% pour-on on the dogs. The control procedure proposed in the present study was an emergency measure and its effectiveness was checked through environmental surveys throughout a one-year period.
- Published
- 2008
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33. Lack of parthenogenesis by Amblyomma cajennense (Acari: Ixodidae).
- Author
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de Freitas CM, Leite RC, Lopes CM, Rodrigues DS, Paz GF, and de Oliveira PR
- Subjects
- Animals, Feeding Behavior, Female, Horses parasitology, Sexual Abstinence, Ixodidae physiology, Parthenogenesis physiology
- Abstract
Some reproductive parameters of adult stages of Amblyomma cajennense ticks were studied. The capacity of virgin females to reproduce by parthenogenesis was evaluated, during an experimental infestation, in absence of males, on a horse (Equus cabalus). Ticks were spread either completely free or in limited sites on the body of the animal. The engorged virgin females showed longer feeding periods and lighter body weights than those that had been fertilized. Some of these unmated females produced smaller egg masses, which had no embryonary development. On the other hand, females that had been inseminated produced larger egg masses, with normal embryonary development that led to viable larvae. Under the studied conditions, A. cajennense females did not reproduce by parthenogenesis.
- Published
- 2002
- Full Text
- View/download PDF
34. Separation of sperm cells by sedimentation technique is not suitable for in vitro fertilization purposes.
- Author
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Yavetz H, Hauser R, Homonnai ZT, Paz GF, Lessing JB, Amit A, and Yogev I
- Subjects
- Cell Survival, Female, Humans, Male, Pregnancy, Prospective Studies, Semen cytology, Sperm Motility, Cell Separation methods, Fertilization in Vitro, Spermatozoa
- Abstract
Two methods of sperm preparation for in vitro fertilization were compared: the swim-up technique vs. the migration-sedimentation technique. The study comprised fresh semen samples obtained from 25 couples treated in the In Vitro Fertilization Unit. Oocytes aspirated in a single cycle were divided into two groups, each inseminated by sperm prepared by one of these techniques. Motility, degree of motility, and normal morphology were improved by both methods. The improvement was greater when the migration-sedimentation technique was applied. However, fertilization rate was significantly higher after the swim-up technique. In order to clarify this contradiction, an additional group of 26 semen samples was divided and then prepared by the swim-up or migration-sedimentation techniques. Sperm quality was examined up to 72 h after separation. Compared with the swim-up technique, sperm characteristics were better after separation by the migration-sedimentation technique. However, this difference abated after 24 h. The better results of the swim-up technique in the "survival experiment' may explain its improved performance in in vitro fertilization, despite lower separation capacity. Thus, the migration-sedimentation technique is not recommended for sperm preparation in in vitro fertilization.
- Published
- 1996
- Full Text
- View/download PDF
35. Management of bilateral nonpalpable testes: laparoscopic diagnosis and orchidectomy.
- Author
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Hauser R, Lessing JB, Samuel D, Yavetz H, Peyser MR, Paz GF, and Homonnai Z
- Subjects
- Adult, Humans, Infertility, Male, Laparoscopy, Male, Orchiectomy, Cryptorchidism diagnosis, Cryptorchidism surgery
- Abstract
Bilateral nonpalpable testes in the adult human are associated with testicular malignancy, infertility and other abnormalities. Investigation for localization of the testes is mandatory, and either orchidopexy or orchidectomy is indicated. Laparoscopy was performed in an azoospermic male with bilateral unpalpable testes. A diagnosis of intra-abdominal testes was made and bilateral orchidectomy was performed. Laparoscopy is recommended for diagnosis and precise localization, as well as for orchidectomy, thus avoiding open abdominal operation in cases of intra-abdominal testes.
- Published
- 1994
- Full Text
- View/download PDF
36. Migration sedimentation technique as a predictive test for the fertilizing capacity of spermatozoa in an in-vitro fertilization programme.
- Author
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Hauser R, Homonnai ZT, Paz GF, Yavetz H, Amit A, Lessing JB, Peyser MR, and Yogev L
- Subjects
- Evaluation Studies as Topic, Female, Humans, Male, Predictive Value of Tests, Sperm Count, Sperm Motility, Cell Separation methods, Fertilization in Vitro, Spermatozoa
- Abstract
The migration-sedimentation technique (MST) has been proposed as a means of separating high quality motile spermatozoa. The present study was conducted in order to evaluate whether sperm performance following separation by MST predicts their fertilizing capacity in an in-vitro fertilization (IVF) programme. Ninety semen specimens were analysed for use in an IVF-embryo transfer (ET) programme. Each specimens was divided into two parts: one was processed in the IVF programme and was used after sperm swim-up separation for insemination of human ova. The other aliquot (0.2 ml) was separated by MST, and the sperm then characterized by their concentration, motility, degree of motility and morphology. Sperm characteristics after separation by MST were then correlated with the results of the IVF-fertilization rates. In 79 of 90 IVF-ET cycles, at least one oocyte was fertilized. All post-MST sperm characteristics were significantly higher in cycles with fertilizations compared to IVF cycles without fertilization. A larger percentage of the total motile spermatozoa were recovered after MST in semen specimens with fertilization, compared to semen specimens without fertilization (39.9 +/- 3.6 and 20.6 +/- 6.6%, respectively; P < 0.05). This value was correlated with the percentage of fertilized oocytes (r = 0.24; P < 0.02). More IVF cycles with fertilizations were recorded in cases in which the recovery of motile sperm was > 25% (P < 0.005), or when more than 1.5 x 10(6) motile spermatozoa were recovered after MST (P < 0.0001). As sperm characteristics after MST correlated significantly with their fertilizing capacity, the MST test could be used in evaluation of the fertilizing capacity of spermatozoa.
- Published
- 1992
- Full Text
- View/download PDF
37. Ca(2+)-independent induction of acrosome reaction by protein kinase C in human sperm.
- Author
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Rotem R, Paz GF, Homonnai ZT, Kalina M, Lax J, Breitbart H, and Naor Z
- Subjects
- Acrosome ultrastructure, Adult, Alkaloids pharmacology, Cell Membrane Permeability physiology, Diglycerides, Down-Regulation drug effects, Exocytosis physiology, Female, Humans, Immunohistochemistry, Ionomycin pharmacology, Male, Microscopy, Electron, Protein Kinase C antagonists & inhibitors, Signal Transduction physiology, Sperm Capacitation physiology, Sperm Motility drug effects, Sperm-Ovum Interactions physiology, Spermatozoa enzymology, Spermatozoa ultrastructure, Staurosporine, Tetradecanoylphorbol Acetate pharmacology, Acrosome physiology, Calcium physiology, Protein Kinase C physiology, Spermatozoa physiology
- Abstract
We report that activated protein kinase C (PKC) can induce acrosome reaction independently of elevated Ca2+. Addition of 12-O-tetradecanoyl phorbol-13-acetate or the membrane-permeable diacylglycerol analog 1-oleoyl-2-acetylglycerol to ejaculated human sperm resulted in stimulation of acrosomal reaction (2- to 3-fold), provided the sperm underwent capacitation. Induction of acrosome reaction by 12-O-tetradecanoyl phorbol-13-acetate was blocked by the PKC inhibitor staurosporine or by down-regulation of endogenous PKC, but not by removal of extracellular Ca2+. Acrosome reaction was also enhanced by the Ca2+ ionophore ionomycin in a Ca(2+)-dependent, PKC-independent fashion. Immunohistochemical analysis with type-specific PKC antibodies revealed the presence of PKC alpha and PKC beta II in the equatorial segment, whereas PKC beta I and PKC epsilon staining was found in the principal piece of the tail. Acrosome reaction, thus far believed to be induced only by elevated Ca2+, can therefore be triggered by activated PKC in a Ca(2+)-independent fashion. The PKC subtypes potentially involved in acrosome reaction are most likely alpha and beta II, whereas the beta I- and epsilon-subspecies might be involved in regulation of flagellar motility of human sperm.
- Published
- 1992
- Full Text
- View/download PDF
38. The predictive fertilization value of the hypoosmotic swelling test (HOST) for fresh and cryopreserved sperm.
- Author
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Hauser R, Yavetz H, Paz GF, Homonnai ZT, Amit A, Lessing JB, Peyser MR, and Yogev L
- Subjects
- Cell Membrane physiology, Embryo Transfer, Fertilization in Vitro, Humans, Insemination, Artificial, Homologous, Male, Osmotic Pressure, Ovulation Induction methods, Predictive Value of Tests, Prospective Studies, Tissue Donors, Cryopreservation, Spermatozoa physiology
- Abstract
Background: The hypoosmotic swelling test (HOST) was recommended as a predictive test for in vitro fertilization (IVF) outcome. These results, however, were controversial and the results for thawed semen were insufficient. The present study was conducted in order to clarify the predictive value of the HOST for IVF in fresh and thawed sperm., Methods: The hypoosmotic swelling test was performed in three groups: husband's fresh semen "subfertile" group, donor's thawed semen group, and donor's fresh semen "fertile" group., Results: No correlation was found between HOST values and sperm characteristics in fresh or thawed sperm. Fresh sperm HOST values correlated with IVF fertilizations. No such correlations were found when thawed sperm was used. HOST values were significantly higher in the fresh fertile donor group than in the fresh subfertile group (P less than 0.001). Following the freezing and thawing process, HOST values decreased dramatically. Nevertheless, the fertilization rate was still higher compared to that of the fresh subfertile group (P less than 0.001). There were significantly more IVF cycles with no fertilizations when HOST values were below 45%., Conclusion: The HOST has a predictive value for fertilization of oocytes in IVF cycles when fresh semen, but not thawed sperm, is used. The freezing-thawing process affects the outer membrane of the spermatozoon and changes its characteristics, leading to a decrease in HOST values. Sperm characteristics that play a role in the fertilization process are not expressed directly by HOST values.
- Published
- 1992
- Full Text
- View/download PDF
39. Further studies on the involvement of protein kinase C in human sperm flagellar motility.
- Author
-
Rotem R, Paz GF, Homonnai ZT, Kalina M, and Naor Z
- Subjects
- Adult, Alkaloids pharmacology, Diglycerides pharmacology, Humans, Immunohistochemistry, Ionomycin pharmacology, Male, Protein Kinase C antagonists & inhibitors, Protein Kinase C metabolism, Spermatozoa enzymology, Staurosporine, Tetradecanoylphorbol Acetate pharmacology, Protein Kinase C physiology, Sperm Motility physiology
- Abstract
Addition of the phorbol ester 12-O-tetradecanoyl phorbol-13-acetate (TPA) or the membrane-permeable diacylglycerol analog, 1-oleoyl-2-acetylglycerol to human sperm resulted in increased motility. The biologically inactive 4 alpha-phorbol 12,13 didecanoate had no effect on flagellar motility. Basal motility was markedly reduced in the absence of Ca2+ in the incubation medium, but TPA-induced sperm motility persisted even in the absence of Ca2+. Sperm motility was also enhanced by the Ca2+ ionophore ionomycin in a Ca2(+)-dependent, protein kinase c (PKC)-independent fashion. Although all stimulants examined here reached maximal response at about 15 min of incubation, nevertheless whereas the effect of TPA and 1-oleoyl-2-acetylglycerol declined at 60 min of incubation, that of ionomycin still persisted. Human sperm PKC activity is extremely low and represents only about 20% and 25% of the specific activity recovered from PC-12 and rat pituitary cells, respectively. Immunohistochemical analysis using various type-specific PKC antibodies revealed staining only in the equatorial segment and the principal piece of the tail. Thus, PKC is present in human ejaculated sperm and is involved in flagellar motility.
- Published
- 1990
- Full Text
- View/download PDF
40. Luteinizing hormone secretion as a response to a second naltrexone administration.
- Author
-
Yogev L, Gottreich A, Homonnai ZT, Yavetz H, and Paz GF
- Subjects
- Animals, Circadian Rhythm, Hypothalamus metabolism, Injections, Intravenous, Luteinizing Hormone blood, Male, Naltrexone administration & dosage, Rats, Rats, Inbred Strains, Time Factors, Hypothalamus drug effects, Luteinizing Hormone metabolism, Naltrexone pharmacology
- Abstract
Previous studies with naltrexone (Nalt), a "long-lasting" opioid antagonist, demonstrated a rapid increase in luteinizing hormone (LH) secretion which gradually declined, reaching baseline values after 1 hr. A second Nalt challenge, 120 min later, caused only a blunted response. This poor reaction has been shown in this study not to be due to lack of pituitary responsiveness, because LH-releasing hormone treatment revealed a normal response. A time-response study was carried out in order to establish the refractory period length, by administering a second Nalt injection at 0 hr (immediately after the first injection) and at 2, 4, 8, 16, and 24 hr after the first bolus. Partial responsiveness could be achieved 2 and 4 hr after the first challenge. However, only after 8 hr was a full response recorded. The diurnal changes in serum LH (nadir at 18.00 hr) did not affect the response to Nalt challenge. It is suggested that in the presence of a Nalt blockade, nonopioid systems are able to "normalize" LH blood levels. However, when Nalt blood levels have fallen sufficiently to allow the endogenous opioid system to take primary control again, then a second Nalt injection will provoke a renewed response.
- Published
- 1990
- Full Text
- View/download PDF
41. Protein kinase C is present in human sperm: possible role in flagellar motility.
- Author
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Rotem R, Paz GF, Homonnai ZT, Kalina M, and Naor Z
- Subjects
- 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine, Adult, Alkaloids pharmacology, Antibodies, Monoclonal, Humans, Immunohistochemistry, Isoquinolines pharmacology, Kinetics, Male, Piperazines pharmacology, Protein Kinase C analysis, Protein Kinase C antagonists & inhibitors, Reference Values, Spermatozoa drug effects, Spermatozoa physiology, Sphingosine pharmacology, Staurosporine, Tetradecanoylphorbol Acetate pharmacology, Protein Kinase C metabolism, Sperm Motility drug effects, Spermatozoa enzymology
- Abstract
We report the presence of protein kinase C (PKC) in ejaculated human sperm as revealed by enzymatic activity assay and indirect immunohistochemistry. PKC is localized in the equatorial segment and in the principal piece of the tail. Addition of phorbol 12-myristate 13-acetate resulted in increased flagellar motility that was blocked by known PKC inhibitors such as sphingosine, staurosporine, and 1-(5-isoquinoylinylsulfonyl)-2-methylpiperazine. A very good correlation (r = 0.9, P less than 0.001) was found between the percentage of PKC-stained sperm cells and motility. We propose that PKC is involved in the regulation of flagellar motility in human sperm.
- Published
- 1990
- Full Text
- View/download PDF
42. Transferrin in seminal plasma and in serum of men: its correlation with sperm quality and hormonal status.
- Author
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Ber A, Vardinon N, Yogev L, Yavetz H, Homonnai ZT, Yust I, and Paz GF
- Subjects
- Adult, Follicle Stimulating Hormone blood, Humans, Immunodiffusion, Luteinizing Hormone blood, Male, Middle Aged, Sperm Count, Sperm Motility, Testosterone blood, Semen metabolism, Spermatozoa physiology, Transferrin metabolism
- Abstract
Transferrin concentrations in the seminal plasma and in serum were measured and correlated with sperm quality (concentration, motility and morphology) and hormonal status (FSH, LH and testosterone) of 75 men aged from 21 to 46 years. A significant positive correlation was found between the seminal plasma concentration of transferrin and the sperm concentration (r = 0.69, P less than 0.0001) and motility (r = 0.39, P less than 0.0001). No other correlations were found. These data confirm that seminal plasma levels of transferrin can be used as a reliable index of sperm quality, and possibly as a Sertoli cell marker.
- Published
- 1990
- Full Text
- View/download PDF
43. The use of phenoxybenzamine treatment in premature ejaculation.
- Author
-
Shilon M, Paz GF, and Homonnai ZT
- Subjects
- Adult, Female, Humans, Male, Middle Aged, Sexual Dysfunction, Physiological psychology, Ejaculation drug effects, Phenoxybenzamine therapeutic use, Sexual Dysfunction, Physiological drug therapy
- Published
- 1984
- Full Text
- View/download PDF
44. Penetration of human ejaculated spermatozoa into human and bovine cervical mucus. I. Correlation between penetration values.
- Author
-
Bergman A, Amit A, David MP, Homonnai ZT, and Paz GF
- Subjects
- Animals, Cattle, Female, Freezing, Humans, In Vitro Techniques, Male, Cervix Mucus physiology, Sperm Motility, Spermatozoa physiology
- Abstract
Midcycle bovine cervical mucus (BCM), fresh (FBCM) or frozen at -20 degrees C (BCMF), and human cervical mucus (HCM) were collected and tested in in vitro penetration tests, using human ejaculated spermatozoa of good quality. Penetration tests were performed at 34 degrees C for 1 hour, and the penetration value (PV) was calculated. Duplicates of each run were in a narrow deviation. Correlations between PV rates of the same semen samples in the 3 sources were found to be significantly high (HCM versus FBCM, r = 0.958; HCM versus BCMF, r = 0.982, and FBCM versus BCMF, r = 0.985), suggesting that human ejaculated spermatozoa penetrate the cervical mucus of all three sources at the same rate.
- Published
- 1981
- Full Text
- View/download PDF
45. Human semen analysis: seminal plasma and prostatic fluid compositions and their interlations with sperm quality.
- Author
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Paz GF, Sofer A, Homonnai ZT, and Kraicer PF
- Subjects
- Body Fluids analysis, Carnitine analysis, Cell Count, Cell Survival, Citrates analysis, Fructose analysis, Glycerylphosphorylcholine analysis, Gonadotropins blood, Humans, Male, Oligospermia metabolism, Prostate, Sperm Motility, Zinc analysis, Semen analysis, Spermatozoa analysis
- Published
- 1977
46. Hormonal control of testosterone secretion by the fetal rat testis in organ culture.
- Author
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Paz GF, Thliveris JA, Winter JS, Reyes IF, and Faiman C
- Subjects
- 1-Methyl-3-isobutylxanthine pharmacology, Animals, Cyclic AMP pharmacology, Leydig Cells ultrastructure, Male, Organ Culture Techniques, Rats, Testis drug effects, Testis metabolism, Chorionic Gonadotropin pharmacology, Estradiol pharmacology, Progesterone pharmacology, Prolactin pharmacology, Testis embryology, Testosterone metabolism
- Published
- 1980
- Full Text
- View/download PDF
47. The possible use of phenoxybenzamine as a male contraceptive drug: studies on male rats.
- Author
-
Paz GF, Shilon M, and Homonnai ZT
- Subjects
- Animals, Genitalia, Male drug effects, Male, Organ Size drug effects, Rats, Rats, Inbred Strains, Sperm Transport drug effects, Testosterone metabolism, Contraceptives, Oral pharmacology, Fertility drug effects, Phenoxybenzamine pharmacology
- Abstract
Treatment of male rats with phenoxybenzamine hydrochloride (PBZ), 70 micrograms/100 g body weight for 5 weeks, caused infertility of the rats. This effect was fully reversible. Studies on the weights of the testes, epididymides, and male accessory sex glands, revealed increased glandular weights (significantly in the testes, epididymides and seminal vesicles). The number of spermatozoa found in the epididymis and vas deferens was significantly increased in the treated rats. Thus, PBZ caused a temporary cessation of sperm transport and paralysis of the muscles of the accessory glands, leading to the absence of ejaculation. In proestrous females mated with treated rats, this caused pseudopregnancy. No changes were found in the sexual behavior of the treated male rats, which was also supported by the absence of changes in the testosterone levels in serum and in testicular tissue. We recommend the use of PBZ in clinical trials, using this well-known drug as the active material for a future contraceptive pill.
- Published
- 1984
- Full Text
- View/download PDF
48. Changes in semen quality and fertility in response to endocrine treatment of subfertile men.
- Author
-
Homonnai ZT, Peled M, and Paz GF
- Subjects
- Female, Humans, Male, Pregnancy, Sperm Motility drug effects, Androgens therapeutic use, Chorionic Gonadotropin therapeutic use, Clomiphene therapeutic use, Gonadotropins, Equine therapeutic use, Infertility, Male drug therapy, Menotropins therapeutic use
- Abstract
786 subfertile men received hormonal treatment in order to improve their semen quality and concentration. Most of the patient's semen was characterised as idiopathic oligo or asthenozoospermia. No cases of hypothalamohypopituitary-hypogonadism were included in this study. 117 men received human chorionic gonadotropin (hCG); 47% showed improvement in semen quality mainly in motility and morphology: 10 pregnancies were recorded among 44 couples (23%). 37 received human menopausal gonadotropin (hMG) + hCG; 46% improvement in semen quality, mainly in the motility and concentration was seen: 3 pregnancies were recorded among 20 couples (15%). 60 men received clomiphene citrate; 47% showed improvement in semen quality mainly in the concentration and motility: 2 pregnancies were recorded among 33 couples (6%). 270 men received androgen, usually in small doses; 61% had improvement in semen quality, mainly in the motility and morphology: 24 pregnancies were recorded among 58 couples (41%). 262 men received pregnant mare serum (PMS; Gestyl) and testosterone; 71% had improvement in semen quality in all the parameters measured especially in motility and vitality, but only 24 pregnancies were recorded among 87 couples (28%). 40 men received treatment for improvement of potency which included androgen, yohimbine and strychnine; 60% improvement in sexual potency, 65% showed a significant improvement in semen quality: 4 pregnancies were recorded among 15 couples (27%). The parameters for improvement of sperm quality were motility, concentration, morphology and vitality. Improvement in semen quality was not necessarily correlated with impregnation of the wives.
- Published
- 1978
- Full Text
- View/download PDF
49. Clomiphene citrate treatment in oligozoospermia: comparison between two regimens of low-dose treatment.
- Author
-
Homonnai ZT, Yavetz H, Yogev L, Rotem R, and Paz GF
- Subjects
- Adult, Clomiphene therapeutic use, Drug Administration Schedule, Humans, Male, Sperm Count, Sperm Motility drug effects, Clomiphene administration & dosage, Oligospermia drug therapy
- Abstract
Clomiphene citrate (CC) is a well-known drug in fertility clinics that is used for increasing gonadotropin secretion. The present study was planned in order to evaluate the efficiency of a new regimen of treatment by 25 mg on alternate days (group A), compared to a daily dose of 25 mg (25 days on, 5 days off, group B), for 4 months. Semen quality was assessed in two matched groups, which consisted of 45 and 44 normogonadotropic oligoterato-asthenozoospermic (OTA) men, respectively. Nine men in group A and 22 in group B did not respond to therapy by improvement in semen quality. The statistical evaluation of the results revealed group A to yield the highest improvement in sperm concentration (P less than 0.0008) and total sperm count (P less than 0.004). Sperm motility was improved only in group A. No changes were recorded in the morphology of the sperm cells or in semen volume. Pregnancy rate after 6 months of follow-up was 26.7% and 20.5%, in couples of groups A and B, respectively. This study implicates the use of CC (25 mg on alternate days) in andrologic clinics as one of the recommended drugs for normogonadotropic OTA subfertile men in order to achieve a significant increase in sperm concentration and total sperm count.
- Published
- 1988
- Full Text
- View/download PDF
50. [Use of intrauterine insemination in subfertile couples].
- Author
-
Yavetz H, Paz GF, and Homonnai ZT
- Subjects
- Female, Humans, Male, Infertility therapy, Insemination, Artificial methods
- Published
- 1989
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