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Gastropod-borne nematodes (GBN) of veterinary concern are mainly represented by lungworms that may infect several mammalian host species. Although recognized as important nematodes throughout the world, these invertebrates have been little studied in South America. The aim of this study was to provide epidemiological, morphological and molecular data on the lungworm larva of a species of Protostrongylus from goats. In March 2019 a study for detection of gastrointestinal nematodes of goats was conducted on the municipality of Paranatama, state of Pernambuco, northeaster Brazil. Faecal samples (n = 217) were analysed through the modified Gordon and Whitlock technique (data not shown), and larvae were detected using the Baermann technique. The sample size was estimated based on the goat population of the study area. Larvae were detected in 18.9 % (41/217) of the analysed samples, and presented a mean length of 339 μm (±52.99 μm) and mean width of 18 μm (±1.46 μm). Morphologically they were similar to Protostrongylus sp. Sequencing of the 18 rRNA gene and BLASTn search revealed strong identity (98.7 %) with homologous sequences of Protostrongylus rufescens available from GenBank. Finally, this study provides new and relevant epidemiological, morphological and molecular data on P. rufescens on goats. Further studies on this nematode are needed in order to elucidate biological aspects such as the seasonal dynamics of infection and intermediate hosts involved in its life cycle.

Parasites of the genus Eimeria induce relevant economic losses in small ruminants worldwide. The aim of this study was to investigate the epidemiology of goats and sheep coccidiosis in a semi-arid region of North-eastern Brazil and to assess whether the rearing system represents a risk factor for the distribution of the infection. A total of 822 fresh faecal samples were collected from the rectum of goats (n = 414) and sheep (n = 408) All samples were individually processed using the technique described by Gordon and Whitlock, and after sporulation in 2.5% Potassium dichromate (K2Cr2O7), an accurate morphometric analysis was performed, with oocysts morphologically identified at species level. The analysis of the risk factors associated with Eimeria infection and system of rearing was performed through univariate analysis and logistic regression. Out of all animals sampled, 70.07% (576/822) scored positive for coccidia oocysts, with an overall prevalence of the infection of 73.91% (306/414) in goats and 66.18% (270/408) in sheep (χ2 = 5.50; p = 0.01). Eight Eimeria species were identified either in goats (i.e., E. arloingi, E. ninakohlyakimovae, E. alijevi, E. jolchijevi, E. caprina, E. chirstenseni, E. caprovina and E. hirci) and in sheep (i.e., E. ovinoidalis, E. parva, E. crandallis, E. granulosa, E. bakuensis, E. ashata, E. faurei, E. pallida). The analysis of risk factors revealed that the semi-intensive system (OR = 1.57) was a risk factor for goats, and, incontrast, intensive system for sheep (OR = 2.45) was safer, relative to Eimeria species transmission. Data reported in this study indicate that a wide species diversity and frequency of coccidia affect small ruminants in the study area. Finally, these findings are pivotal to better understand the dynamics of infection by this coccidian in these herds, as well as sound as an alert for practice veterinarians of the region, regarding the most common pathogenic species.

In Brazil, active infections of Rickettsia spp. is confirmed in all regions, involving various species of ticks. During investigation of a new focus of Spotted Fever (SF) incidence in the state of Pernambuco, northeastern Brazil, tick species Rhipicephalus sanguineus sensu lato (Latreille), and Amblyomma pseudoconcolor were collected from one Canis familiaris and four Euphractus sexcinctus, respectively, and analized for the presence of rickettsial genes. Ten A. pseudoconcolor ticks (90.9%) were found to be infected with Rickettsia, whereas no evidence of Rickettsia spp. was found in R. sanguineus s. l. Genetic analysis based of five rickettsial genes showed that the detected strain is most closely related to Rickettsia amblyommatis (formerly Candidatus Rickettsia amblyommii). R. amblyommatis was, for the first time, detected in Amblyomma pseudoconcolor and the results pointed to this tick like a potential vector in the enzootic cycle of R. amblyommatis in a typical semiarid Brazilian savannah region. In conclusion, despite the need for further studies to confirm if R. amblyommatis was responsible for the observed case in the state of Pernambuco, the presence of this bacterium during an SF focussed investigation should be a major concern in terms of public health due the capacity of SF for rapid and extensive dispersion within Brazilian territory.

Vector-borne diseases are considered public health concerns. As vaccines for some of these diseases are not available or still have serious restrictions, the vector control is an important strategy. Aedes aegypti mosquitoes can transmit dengue, yellow fever, chikungunya and Zika viruses. Chemical compounds are used to control A. aegypti populations which are usually toxic to non-target organisms, and thus the safety of their use is questionable. This work reports the purification and characterization of a lectin from Chlorella vulgaris microalgae (CvL) and its toxicity to the A. aegypti fourth instar larvae (L4). CvL was isolated (purification factor of 8.72; yield of 6.67) from the C. vulgaris aqueous extract (AE) with hemagglutinating activity of 185,130 titre mg−1. The characterization showed that CvL is a 17 kDa protein whose activity was inhibited various carbohydrates, resisted to heating up to 60 °C and was stable over a broad pH range. Additionally, CvL activity was strongly reduced by monovalent and divalent metal ions. AE and CvL were toxic to L4 and the concentrations that killed 50% of larvae after 24 h were 10.62% (v/v) and 164.24 μg mL−1, respectively. CvL inhibited the activity of trypsin-like enzymes from L4 gut and this effect, as well as the larvicidal activity, were abolished when the lectin was denatured by heating or when its carbohydrate-binding site was blocked by fructose or azocasein. These findings points the C. vulgaris biomass as a new source of a biomaterial with potential to control A. aegypti larvae by inhibition of trypsin-like enzymes representing a larvicidal mechanism.

The FLOTAC® technique represents a highly sensitive method for the isolation of oocysts, eggs, and larvae of parasites in faeces. This assay could be used for detecting free-living stages of nematodes in the pasture but no attempt has been assessed so far. Therefore, the performance of FLOTAC® technique for isolating infective larvae of nematodes in the environment was investigated and compared with the spontaneous sedimentation (SST) and centrifugal sedimentation (CST) techniques. The study was conducted in a horse farm located in northeastern Brazil, where the occurrence of strongyle larvae had been previously reported. Pasture samplings were collected monthly from January to May 2016 in a 376 m2 crop area harvested with the Guinea grass Panicum cultivar Massai. The recovery of third-stage larvae (L3) was performed using the FLOTAC®, SST and CST techniques. Values of Cohen's kappa coefficient, sensitivity, specificity, positive and negative predictive values, and accuracy of each technique were assessed. Although strongyle larvae were evenly detected, with the FLOTAC® technique yielded the highest number of positive samples (i.e., 41%, 41/100, p

Species of filarial nematodes belonging to the genera Dirofilaria and Acanthocheilonema are recognised as common parasites of dogs throughout the world. Recently, other filarioids featured by the presence of dermal microfilariae (e.g., Onchocerca lupi and Cercopithifilaria spp.) have been recognised in Europe. In Brazil, reports of filarioids in dogs are limited to Dirofilaria immitis, Acanthocheilonema reconditum and Cercopithifilaria bainae. To investigate the distribution of filarial infections in dogs living in an endemic region from northeastern Brazil, blood and skin samples (n=104) were microscopically (modified Knott's test and skin snip sediment examination) and molecularly evaluated. Twenty-two dogs (21.15%) were positive at microscopic and/or molecular examination for at least one filarioid species, with 21 (20.19%) animals positive for blood microfilariae at molecular and/or at microscopic examination. Microfilariae of D. immitis were detected in 12 (11.54%) animals, with co-infection of D. immitis and A. reconditum observed in four (3.85%) individuals. One animal was positive for C. bainae at both microscopic and molecular examination. Analysis of sequence obtained in the present study showed significant alignment identity with that of C. bainae from Europe. Considering that in the area of study arthropod vectors (mosquitoes, fleas and ticks) are prevalent throughout the year, preventive measures should be disposed in order to avoid the animal infestation and pathogen infection.

Cutaneous leishmaniasis caused by Leishmania braziliensis is endemic in Brazil, where Lutzomyia whitmani is the most important vector involved in the transmission to humans, particularly in the peridomestic environment. Herein, we assessed the ecology of sand flies, including Lu. whitmani, in a low-density residential rural area with mixed forest/agricultural exploitation in north-eastern Brazil, where cutaneous leishmaniasis is endemic. Particularly, we hypothesized that sand fly abundance was correlated with climatic variables. Sand fly collections were carried out monthly from August 2013 to August 2014, using seven CDC light traps, for three consecutive nights, in three kinds of environments: indoor, peridomicile and forest. Collected sand flies were identified based on morphology and females of Lu. whitmani (n=169), Lu. amazonensis (n=134) and Lu. complexa (n=21) were selected and tested by PCR for Leishmania (Viannia) spp. In total, 5167 sand flies belonging to 19 species were identified, being that Lu. choti (43.2%) was the most frequent species, followed by Lu. amazonensis (16.6%), Lu. whitmani (15.8%), Lu. sordellii (10.7%) and Lu. quinquefer (5.8%), which together represented over 90% of the collected sand flies. All females tested by PCR were negative. The number of sand flies collected daily was positively correlated with temperature and negatively correlated with rainfall and relative humidity. Furthermore, there was a positive correlation between daily number of sand flies and daily average saturation deficit. This study points out that the number of sand flies captured daily is correlated to climatic variables, including saturation deficit, which may represent a useful parameter for monitoring sand fly populations in leishmaniasis-endemic areas.

Clinical signs are seldom observed in feline heartworm disease, and the pathophysiological changes in the lungs of infected animals remain undefined. The goal of this study was to evaluate the structural and ultrastructural changes in the lungs of cats experimentally infected with Dirofilaria immitis. Six healthy cats were each infected with two adult heartworms by intravenous transplantation (Receptor Group, RG). The control group consisted of two uninfected animals kept under the same conditions as the RG. At 42 days after transplantation, all cats were euthanized and necropsied for worm recovery and collection of lung samples for examination by light microscopy (LM) and transmission electron microscopy. By LM, lung sections from the six infected cats exhibited bronchial and bronchiolar lesions. Alterations in all tissues of the pulmonary arteries were observed in the infected animals. In conclusion, cats infected experimentally with D. immitis developed lesions in their lungs as a consequence of arterial disease and intense interstitial pneumonia.

This paper reports a quantitative real-time polymerase chain reaction (q-PCR) based on the msa2c gene and standardized with Platinum SYBR Green/ROX for the detection of Babesia bovis in cattle. The msa2c q-PCR amplified a DNA fragment with average dissociation temperature of 77.41°C (± 0.25°C). No amplification was detected when DNA from B. bigemina, A. marginale or Bos taurus was used as the template. The detection limit of the msa2c q-PCR was 1000 copies per ml of blood sample, with a linear correlation between the number of msa2c copies and threshold cycle. The comparison between msa2c q-PCR and conventional PCR for cytochrome b revealed 88.8% agreement, with a Kappa index of 0.75. In the comparison between msa2c q-PCR and an enzyme-linked immunosorbent assay (ELISA) with semi-purified B. bovis antigen, agreement was 96.3% and the Kappa index was 0.91. The agreement between three tests was 85.8%. The msa2c q-PCR detected a higher number of positive cattle than conventional PCR in an enzootically stable area, but did not differ significantly from ELISA. No significant differences were detected between the three diagnostic tests with cattle from an enzootically unstable area. All animals raised on a tick-free facility were negative for B. bovis in the three tests. These results suggest that msa2c q-PCR is a useful test for the detection of B. bovis infection.

This study evaluated the performance of the EIE-leishmaniose-visceral-canina-Bio-Manguinhos (EIE-LVC) kit and to compare it with that of the IFI-leishmaniose-visceral-canina-Bio-Manguinhos (IFI-LVC) kit. Four groups of dogs were studied: group 1 (G1), dogs with clinical signs indicative of CVL and testing positive for the parasite (n = 25); group 2 (G2), dogs with only a presumed diagnosis of CVL (n = 62); group 3 (G3), dogs that had never lived in an area where CVL is endemic and never received a blood transfusion (n = 16); group 4 (G4), dogs carrying other parasites: such as babesiosis (n = 4), ehrlichiosis (n = 6) and demodicosis (n = 1). G1 and G3 were used for the calculation of sensitivity and specificity, respectively. The EIE-LVC showed a sensitivity of 72% (IC 95%: 50.4-87.1%) and a specificity of 87.5% (IC 95%: 60.4-97.8%). The value of the kappa index was 0.975 (CI 95%: 0.926-1.024), which represents an excellent fit. For IFI-LVC, the sensitivity was 68.0% (CI 95%: 46.4-84.3%) and the specificity 87.5% (CI 95%: 60.4-97.8%). When the tests were conducted in parallel, sensitivity was 92.0% (CI 95%: 72.5-98.6%) and specificity 75.0% (CI 95%: 47.4-91.7%). However, when conducted consecutively, the tests showed a sensitivity of 48.0% (CI 95%: 28.3-68.2%) and a specificity of 100.0% (CI 95%: 75.9-99.4%). The analysis of clinically suspected dogs using IFI-LVC and EIE-LVC kits in parallel, revealed that 26/62 animals were positive. Cross-reaction was observed in a dog with demodicosis. These results lead to the following conclusions: (1) the performance of the EIE-LVC kit is not statistically different from the IFI-LVC and (2) the kits must be used in parallel if higher sensitivity is required, reducing the number of false-negative results.

Human visceral leishmaniasis is endemic in the northeast of Brazil, where the domestic dog is an important parasite reservoir in the infectious cycle of Leishmania chagasi. In this study, we evaluated the clinical signs of canine visceral leishmaniasis (CVL), serum protein profile and the antileishmanial IgG antibody production in 86 dogs living in northeast endemic areas of leishmaniasis. Thirty dogs from a leishmaniasis-free area were used as a control group. The major clinical signs of CVL seen were emaciation and skin ulcers (80%), followed by onychogryphosis and conjunctivitis (73%). Depilation was observed in 60% of animals while lymphadenomegaly, splenomegaly, liver enlargement or kidney involvement was less frequent (< or =20%). VL seropositive dogs presented with serum hyperproteinemia, hypoalbuminemia, hypergammaglobulinemia and decreased albumin/globulin ratio. A lower sensitivity and higher specificity was observed for promastigote indirect fluorescent antibody test (IFAT) (83 and 100%, respectively) compared with enzyme-linked immunosorbent assay (ELISA) (94 and 90%), which uses a crude extract of Leishmania. There was a positive correlation between IFAT and ELISA titers of antileishmanial IgG antibodies (Spearman test, P < 0.05), which was augmented in CVL dogs. This study found that the determination of serum protein, A/G ratio and the use of two different leishmanial serological tests like IFAT and ELISA are essential in CVL screening.