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Hantavirus pulmonary syndrome (HPS) is an increasing health problem in Brazil because of encroachment of sprawling urban, agricultural, and cattle-raising areas into habitats of subfamily Sigmodontinae rodents, which serve as hantavirus reservoirs. From 1993 through June 2007, a total of 884 cases of HPS were reported in Brazil (case-fatality rate 39%). To better understand this emerging disease, we collected 89 human serum samples and 68 rodent lung samples containing antibodies to hantavirus from a 2,500-km-wide area in Brazil. RNA was isolated from human samples and rodent tissues and subjected to reverse transcription-PCR. Partial sequences of nucleocapsid protein and glycoprotein genes from 22 human and 16 rodent sources indicated only Araraquara virus and Juquitiba virus lineages. The case-fatality rate of HPS was higher in the area with Araraquara virus. This virus, which may be the most virulent hantavirus in Brazil, was associated with areas that have had greater anthropogenic changes. [ABSTRACT FROM AUTHOR]

Background: Piauí is located in Northeastern Brazil, an endemic area for Chagas disease, with the Brazilian semiarid representing the second region in number of people infected by the parasite Trypanosoma cruzi. The state of Piauí is one of the most socially vulnerable territories with direct impact on the access to diagnosis and treatment of Chagas disease for the population living in rural communities. Triatoma brasiliensis is the vector species of greatest epidemiological importance in Northeastern Brazil. We investigated the triatomine fauna and risk factors associated to T. cruzi transmission in two municipalities, Pedro II and Oeiras, located in different mesoregions of Piauí., Methods: Twenty-three rural areas were selected for triatomines search and serological survey of the population. The analysis of triatomines consisted on identifying T. cruzi infection index by microscopy and kDNA-PCR followed by parasite genotyping through the use of multilocus PCR to characterize the discrete typing units (DTUS), and the identification of food sources using PCR directed to the 12S rRNA gene of vertebrates and sequencing., Results: A total of 1,043 triatomines identified as T. brasiliensis, Triatoma pseudomaculata, Rhodnius nasutus, Rhodnius sp. and Panstrongylus lutzi were collected. The overall positivity for T. cruzi was 4.6% and 11.4% by microscopy and kDNA-PCR, respectively. The DTUs TcV (∼ 44%) and TcI (∼ 43%) were the most prevalent in either single or mixed infections. This is the first report of TcV and TcVI infections in vectors of Piauí. The most frequent blood source was Homo sapiens (46.5%), of which ∼ 42% individuals (28/67) were collected indoors and four of them (14.3%) tested positive for T. cruzi kDNA in Pedro II. Chicken (∼ 19%), domestic cat (∼ 17%) and others were also identified as feeding sources for triatomines. Serological survey revealed 2% seroprevalence. Variables as age over 60 years (p = 0.01), Black race (p = 0.002) and occupation as retired (p = 0.004) significantly influenced the seropositivity., Conclusion: Despite the reduced seroprevalence of the population, the epidemiological scenario of Chagas disease in both municipalities highlights the risk of the re-emergence of domestic vector-borne transmission. Ensuring continued entomological surveillance and vector control programs and providing access to diagnosis and treatment for the susceptible population are still needed., Competing Interests: Declarations. Ethics approval: The study was approved by the Human Research Ethics Committee of the Federal University of Piauí (protocol 4.343.423). Participants were not identified and all individuals signed a statement agreement to participate in the research. Triatomine collection was registered and approved by the Biodiversity Authorization and Information System – SISBIO (Chico Mendes Institute for Biodiversity Conservation, Brazil), under license 77174-1. No animals were used in the present study. The mentioned animals are the result of the identification of available vertebrate DNA sequences in the GenBank database. Clinical trial number: Not applicable. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

This study aimed to compare AFM 1 occurrence in different cheese types produced by organic and conventional systems; and to evaluate the risk of food exposure to AFM 1. A total of 176 commercial cheeses of 17 types were analyzed, 84 of organic and 92 of conventional production. Determination of AFM 1 was performed by high- performance liquid chromatography (HPLC), being detected in 30.5% of samples, with 4.8% of organic cheese samples presenting quantifiable AFM 1 values between 0.88 and 1.50 μg/kg. On the other hand, 4.3% of conventional cheese samples with values between 0.79 and 6.70 μg/kg. Two conventional cheese samples were above the limit of AFM 1 allowed for cheeses by the Brazilian legislation. No statistical difference were found between organic and conventional cheeses regarding the occurrence (p = 0.1780) and concentration of AFM 1 (p = 0.1810), according to the Chi-square and the T test, respectively. Estimated daily intake (EDI) and hazard index (HI) of dietary exposure to AFM 1 were 0.26 ng/kg/day and 1.28 ng/kg/day, respectively, for conventional cheese samples, and 0.09 ng/kg/day and 0.47 ng/kg/day for organic samples, with no statistical difference for EDI (p = 0.1729) and HI (p = 0.1802) between the two production systems. Comparison between several cheese types from conventional and organic systems indicated that AFM 1 is an obstacle to dairy production. Control and prevention of AFM 1 contamination, as well as detoxification methods in the final products, are necessary. In the case of organic products, additional research is needed in order to determine which control and detoxification methods should be allowed in this production system., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

The development of biomaterials to enable application of antimicrobial peptides represents a strategy of high and current interest. In this study, a bioparticle was produced by the complexation between an antimicrobial polypeptide and the biocompatible and biodegradable polysaccharides chitosan- N -arginine and alginate, giving rise to a colloidal polyelectrolytic complex of pH-responsive properties. The inclusion of the polypeptide in the bioparticle structure largely increases the binding sites of complexation during the bioparticles production, leading to its effective incorporation. After lyophilization, detailed evaluation of colloidal structure of redispersed bioparticles evidenced nano or microparticles with size, polydispersity and zeta potential dependent on pH and ionic strength, and the dependence was not withdrawn with the polypeptide inclusion. Significant increase of pore edge tension in giant vesicles evidenced effective interaction of the polypeptide-bioparticle with lipid model membrane. Antibacterial activity against Aeromonas dhakensis was effective at 0.1% and equal for the isolated polypeptide and the same complexed in bioparticle, which opens perspectives to the composite material as an applicable antibacterial system.

Sweetpotato is a staple crop in Brazil presenting a smaller number of pathogens and diseases in comparison with other root and tuberous crops. Root-knot nematodes are among the most serious sweetpotato root pathogens. The impact of these pathogens also extends to succeeding crops. Because in Brazil, it is common to cultivate more than one crop per season, this problem is rapidly disseminated. The aim of this study was to assess the resistance of two sweetpotato clones and four commercial sweetpotato genotypes to three different Meloidogyne species. Assays were performed under greenhouse and field conditions. 'CIP BRS Nuti' and 'Canadense' were resistant to Meloidogyne incognita , M . javanica , and M . enterolobii under greenhouse conditions. This finding was obtained based on the reproduction factor < 0.2, meaning that the initial population of 5,000 nematodes was reduced to <1,000 individuals after 90 days of inoculation. Tomato and sweetpotato cultivar Beauregard, known to be susceptible to the three nematode species, were highly damaged by the pathogens. Similar results were also observed under field conditions. To our knowledge, 'CIP BRS Nuti' and 'Canadense' are the first South American commercial cultivars with triple nematode resistance.

Background: Round fish is one of the most consumed fish in Brazil. Farmed fish feed is based mainly on grains, which are susceptible to contamination by mold and mycotoxins. Aspergillus spp., Penicillium spp. and Fusarium spp. are the major mycotoxins producers. The presence of potentially toxigenic fungi in the diet is a concern due to the possibility of cumulative toxins in fish tissues, becoming a risk to food safety. This study aims to assess the mycobiota of fish feed and the occurrence of aflatoxin residues in round fish tissues. Feed and fish samples were collected from fish farming and fish pay properties. Feed was submitted to mold counting and mold identification. The round fish liver and muscle were submitted to the detection and quantification of aflatoxins B 1 , B 2 , G 1 and G 2 by high-performance liquid chromatography., Results: In evaluated feed, mold counts in the samples ranged from 2.0 to 4.7 log colony forming units g -1 and the major genera found were Penicillium (61.5%) and Aspergillus (34.6). Aflatoxin B 1 (AFB 1 ) was detected in 70% liver samples and 43.3% muscle samples, at levels up to 5.70 and 1.13 μg kg -1 , respectively., Conclusion: It is concluded that, although the levels were lower than those recommended by Brazilian legislation, round fish are being exposed to diets naturally contaminated by aflatoxins and are susceptible to toxins accumulation in tissues. Therefore, regulations regarding feed should consider limits for mold and aflatoxin contamination in fish edible tissues should be monitored in order to ensure consumers' safety. © 2021 Society of Chemical Industry., (© 2021 Society of Chemical Industry.)

Introduction: Endometritis is a condition marked by inflammation of the endometrium that affects dairy cows from 21 days after parturition, causing damage to herd fertility and economic losses on farms. The use of active compounds obtained from plant sources has gained importance as disease treatment agents in farm animals due to the high resistance rates currently observed against traditional antibiotics commonly used. The study was carried out to examine the chemical composition and to investigate the antibacterial activity of rosemary, cinnamon, cloves, eucalyptus, lemon, oregano and thyme essential oils against the reference strain of Escherichia coli (ATCC 25922), Fusobacterium necrophorum (ATCC 25286), Trueperella pyogenes (ATCC 19411) and Staphylococcus aureus (ATCC 29213), considered as typical bacteria causing endometritis., Methodology: The chemical composition of the seven essential oils were analyzed by GC-MS and their antibacterial activity was evaluated by the disc diffusion method., Results: Thirty-six components were identified in total using GC-MS analyzes. The main compounds were cinnamaldehyde (86.5% for cinnamon essential oil), eugenol (85.7% for clove essential oil), 1,8-cineol (80% for eucalyptus and 47.8% rosemary essential oils), limonene (65.5% for lemon essential oil), carvacrol (72.1% for oregano essential oil) and thymol (48.8% for thyme essential oil). The disc diffusion assay revealed that cinnamon, clove, oregano, and thyme essential oils showed the best results compared to the other three essential oils, showing the largest zone of inhibition against all bacteria evaluated., Conclusions: These findings indicated that essential oils are a potential agent to be used as an alternative for bovine endometritis treatment., Competing Interests: No Conflict of Interest is declared, (Copyright (c) 2020 Renan Braga Paiano, Jeannine Bonilla, Ricardo Luiz Moro de Sousa, Andrea Micke Moreno, Pietro Sampaio Baruselli.)

It is suggested that Bovine kobuvirus (BKV) is involved in the etiology of gastroenteric diseases especially among calves; however, this association remains unknown. This study evaluated 216 fecal samples from cattle with and without diarrhea symptoms obtained from different regions of Brazil. A 216 bp fragment of the BKV 3D gene was amplified by RT-PCR in 14.4 % (31/216) of the studied samples, and 17 samples were subjected to nucleotide sequencing. All positive samples were obtained from animals aged less than 5 months, and most of animals presented diarrhea (p < 0.05). Phylogenetic analyses showed that the obtained sequences were grouped within the genogroup 2 of BKV forming subclades specific for each Brazilian municipality sampled. In addition, the alignment of the sequences revealed differences of nucleotides between sequences from different locations. Our results indicate for the first time that there is a regional genotypic differentiation of BKV in Brazil.

Bovine astrovirus (BoAstV) is associated with gastroenterical disorders such as diarrhea, particularly in neonates and immunocompromised animals. Its prevalence is >60 % in the first five weeks of the animal's life. The aim of this study was to detect and perform a phylogenetic analysis of BoAstV in Brazilian cattle. A prevalence of 14.3 % of BoAstV in fecal samples from 272 head of cattle from different Brazilian states was detected, and 11 samples were analyzed by nucleotide sequencing. The majority of positive samples were obtained from diarrheic animals (p < 0.01). Phylogenetic analysis revealed that Brazilian samples were grouped in clades along with other BoAstV isolates. There was 74.3 %-96.5 % amino acid sequence similarity between the samples in this study and >74.8 % when compared with reference samples for enteric BoAstV. Our results indicate, for the first time, the occurrence of BoAstV circulation in cattle from different regions of Brazil, prevalently in diarrheic calves.

Activation of the immune response in hantavirus cardiopulmonary syndrome (HCPS) leads to a high TNF production, probably contributing to the disease. The polymorphic TNF2 allele (TNF -308G/A) has been associated with increased cytokine production. We investigated the association of the TNF2 allele with the outcome of hantavirus infection in Brazilian patients. A total of 122 hantavirus-exposed individuals (26 presenting HCPS and 96 only hantavirus seroconversion) were studied. The TNF2 allele was more frequently found in HCPS patients than in individuals with positive serology for hantavirus but without a history of HCPS illness, suggesting that the TNF2 allele could represent a risk factor for developing HCPS.

The purposes of this study were to model a vaccination regimen for Newcastle disease virus (NDV) in pigeons, and to evaluate the susceptibility and behavior of vaccinated birds against a highly pathogenic NDV Brazilian strain. Antibody response was assessed by means of hemagglutination inhibition test (HI), and viral genome excretion by means of RT-PCR. Vaccinal strains (La Sota and Ulster) induced high antibody titers without any adverse effects, both in inoculated and in sentinel birds. A viral strain pathogenic for chickens did not produce clinical signs of the disease in experimentally infected pigeons. Only 4 out of 10 vaccinated pigeons shed NDV genome, and just for two days. Results confirmed the high infectivity of the vaccinal strains used, as all nonvaccinated pigeons showed antibody titers as high as those of vaccinated birds.

Paracoccidioidomycosis, the major systemic mycosis in Latin America, is caused by fungus Paracoccidioides brasiliensis. To analyze the influence of inducible nitric oxide synthase (iNOS) in this disease, iNOS-deficient (iNOS(-/-)) and wild-type (WT) mice were infected intravenously with P. brasiliensis 18 isolate. We found that, unlike WT mice, iNOS(-/-) mice did not control fungal proliferation, and began to succumb to infection by day 50 after inoculation of yeast cells. Typical inflammatory granulomas were found in WT mice, while, iNOS(-/-) mice presented incipient granulomas with intense inflammatory process and necrosis. Additionally, splenocytes from iNOS(-/-) mice did not produce nitric oxide, however, their proliferative response to Con-A was impaired, just like infected WT mice. Moreover, infected iNOS(-/-) mice presented a mixed pattern of immune response, releasing high levels of both Th1 (IL-12, IFN-gamma and TNF-alpha) and Th2 (IL-4 and IL-10) cytokines. These data suggest that the enzyme iNOS is a resistance factor during paracoccidioidomycosis by controlling fungal proliferation, by influencing cytokines production, and by appeasing the development of a high inflammatory response and consequently formation of necrosis. However, iNOS-derived nitric oxide seems not being the unique factor responsible for immunosuppression observed in infections caused by P. brasiliensis.

Objective: Hantaviruses are rodent-borne RNA viruses that have caused hantavirus cardiopulmonary syndrome in several Brazilian regions. In the present study, geographical distribution, seroprevalence, natural host range, and phylogenetic relations of rodent-associated hantaviruses collected from seven counties of Southeastern Brazil were evaluated., Methods: ELISA, RT-PCR and phylogenetic analysis were used in this study., Results: Antibodies to hantavirus were detected in Bolomys lasiurus, Akodon sp. and Oligoryzomys sp., performing an overall seroprevalence of 5.17%. All seropositive rodents were associated with grasslands or woods surrounded by sugar cane fields. Phylogenetic analysis of partial S- and M-segment sequences showed that viral sequences isolated from B. lasiurus specimens clustered with Araraquara virus. However, a sequence from Akodon sp. shared 100% similarity with Argentinian/Chilean viruses based on the partial S-segment amino acid sequence., Conclusion: These results indicate that there are associations between rodent reservoirs and hantaviruses in some regions of Southeastern Brazil, and suggest the existence of additional hantavirus genetic diversity and host ecology in these areas., (Copyright 2008 S. Karger AG, Basel.)

Oropouche, Caraparu, Guama, Guaroa and Tacaiuma viruses (Orthobunyavirus genus) cause human febrile illnesses and/or encephalitis. To achieve a therapeutical agent to prevent and/or treat these diseases we evaluated the antiviral action of Interferon-alpha (IFN-alpha) on these orthobunyaviruses. In vitro results showed that all the studied orthobunyaviruses are susceptible to antiviral action of IFN-alpha, but this susceptibility is limited and dependent on both concentration of drug and treatment period. In vivo results demonstrated that IFN-alpha present antiviral action on Oropouche and Guaroa viruses when used as a prophylactic treatment. Moreover, a treatment initiated 3h after infection prevented the death of Guaroa virus infected-mice. Additionally, mortality of mice was related to the migration and replication of viruses in their brains. Our results suggest that IFN-alpha could be potentially useful in the prevention of diseases caused by Oropouche virus and in the prevention and/or treatment of diseases caused by Guaroa virus.

Objective: Oropouche, Caraparu, Guama, Guaroa and Tacaiuma are ssRNA viruses that belong to the genus Orthobunyavirus and have been associated with human febrile illnesses and/or encephalitis. In this study, we evaluated the antiviral action of mycophenolic acid (MPA) on theseorthobunyaviruses to achieve a therapeutic agent to treat the diseases caused by these viruses., Methods: The in vitro antiviral evaluation to MPA was done by using plaque assay at different periods of treatment., Results: Results showed that MPA at a concentration of 10 microg/ml has significant antiviral activity on Tacaiuma virus when treatment was initiated either 24 h before or 2 h after viral infection. Moreover, MPA has an inhibitory effect on Guama virus replication, but only when treatment was initiated before cell infection. Addition of guanosine in the culture reverted the inhibitory effect of MPA on Tacaiuma and Guama viruses, suggesting that the antiviral activity of this substance was via depletion of the intracellular guanosine pool., Conclusion: Our results suggest that MPA would not be a good therapeutic agent to treat the diseases caused by Oropouche, Caraparu, Guama, Guaroa, and Tacaiuma viruses., ((c) 2007 S. Karger AG, Basel.)

Oropouche, Caraparu, Guama, Guaroa, and Tacaiuma are viruses (genus Orthobunyavirus) that cause human febrile illnesses and encephalitis. The goal of this study was to evaluate the antiviral action of ribavirin on these orthobunyaviruses to achieve a therapeutical agent to treat the diseases caused by these viruses. In vitro results showed that ribavirin (50 microg/mL) had antiviral activity only on the Tacaiuma virus. Addition of guanosine in the culture reversed the antiviral effect of ribavirin on Tacaiuma virus, suggesting that ribavirin inhibited this virus by reducing the intra-cellular guanosine pool. Moreover, ribavirin was not an effective drug in vivo because it was unable to inhibit the death of the mice or virus replication in the brain. The results suggest that ribavirin has no antiviral activity on the Oropouche, Caraparu, Guama, Guaroa, or Tacaiuma viruses; consequently, ribavirin would not be a good therapeutical agent to treat these arboviruses.

Hantaviruses are the causative agents of severe human diseases such as Cardiopulmonary Syndrome (CPS), described for the first time in 1993. Approximately 200 cases of this emergent disease were reported in Brazil until August 2002, with a 40% fatality rate. In May 2001, a hantavirus serologic survey was carried out among 15-70-year-old inhabitants of Jardinopolis County, State of São Paulo, Brazil. Blood samples of 818 inhabitants from urban and rural areas were collected by digitopuncture and IgG antibodies, detected by an indirect enzyme-linked immunosorbent assay (ELISA) to the N recombinant protein of Andes hantavirus, were found in 14.3% of the samples, showing that this infection is common in Jardinopolis County, especially among adults irrespective of sex, profession, history of contact with rodents, or history of severe pneumonia. The results of the survey do not corroborate the idea that hantavirus infections are associated to rural activity and rodent contact, as observed with 20 Cardiopulmonary Syndrome cases occurred in the same region. Hantaviruses may be causing unrecognized infections, either asymptomatic or clinically nonspecific in addition to the syndrome. It may also be the case that more than one hantavirus type could be circulating in this region, causing mostly benign infections., (Copyright 2003 Wiley-Liss, Inc.)

A liquid phase blocking ELISA (LPB-ELISA) was adapted for the detection and quantification of antibodies to Newcastle disease virus. Sera from vaccinated and unvaccinated commercial flocks of ostriches (Struthio camelus) and rheas (Rhea americana) were tested. The purified and nonpurified virus used as the antigen and the capture and detector antibodies were prepared and standardized for this purpose. The hemagglutination-inhibition (HI) test was regarded as the reference method. The cutoff point for the LPB-ELISA was determined by a two-graph receiver operating characteristic analysis. The LPB-ELISA titers regressed significantly (P < 0.0001) on the HI titers with a high correlation coefficient (r = 0.875). The two tests showed good agreement (kappa = 0.82; P < 0.0001), relative sensitivity (90.91%) and specificity (91.18%), and accuracy (91.02%), suggesting that they are interchangeable.