Revista Brasileira De Parasitologia Veterinaria最新文献

The genus Ceratomyxa is composed of approximately 300 described species, most of which are found parasitizing hosts in marine aquatic environments. The present study, through phylogenetic, molecular and morphological analyses, described a new species of Ceratomyxa found parasitizing Leporinus affinis specimens from the Tartarugalzinho River, in municipality of Tartarugalzinho, state of Amapá, Brazil. The new species was found parasitizing the urinary bladder of L. affinis. The myxospores of Ceratomyxa affinis n. sp. are 7.2 µm long and 43.2 µm thick with a posterior angle of 170º. The polar capsules measure 3.9 µm long and 4.05 µm wide. Based on morpho-molecular analyses, it was possible to prove that Ceratomyxa affinis n. sp. is a new species, contributing to the knowledge of the parasitic fauna of fish in the Amazon region.

The objective of this study was to synthesize and evaluate the in vitro activity of aminochalcones against Haemonchus contortus eggs and adults. Aminochalcones 1 and 2 were synthesized using Claisen-Schmidt condensation and characterized using Fourier-transform infrared spectroscopy, nuclear magnetic resonance, and mass spectrometry. The activity of both aminochalcones was assessed in the egg hatch test and that of aminochalcone 1 was further evaluated in the adult worm motility test using multiresistant H. contortus. The chemical structures of the synthesized compounds were confirmed, and changes induced in eggs and adults were assessed using scanning electron microscopy (SEM). Aminochalcones 1 and 2 inhibited larvae hatching by 98.70 and 99.89%, respectively, at concentrations of 0.25 and 1 mg/mL. SEM images revealed structural and morphological changes in eggs treated with both compounds. After 12 h of exposure to aminochalcone 1 (1.25 mg/mL), all adult nematodes were immobile, and wrinkling of the cuticle was observed. These findings indicate the ovicidal effect of aminochalcones and the inhibition of worm motility by aminochalcone 1. Our preliminary study demonstrated, for the first time, the anthelmintic activity of this class of compounds against gastrointestinal nematodes of small ruminants and suggest further anthelmintic evaluation.

The diagnosis of canine visceral leishmaniasis (CVL) relies on parasitological, molecular methods and serological. However, there are difficulties in using these methods to monitor the disease, and there is a need for more efficient diagnostic alternatives for dogs with suspected visceral leishmaniasis, also using clinical aspects of the animals, which that can be useful for surveillance and control. This study aimed to evaluate the serological diagnostic potential of recombinant antigens in order to improve CVL diagnosis. Disease diagnosis, clinical evaluation, and collection of biological samples for laboratory analysis were performed on dogs from the Tirirical District in São Luís, Maranhão, Brazil. The animals were divided into four groups: clinically suspected dogs for visceral leishmaniasis (VL), subclinical dogs for VL, animals with infections, and healthy animals from an endemic area. Subsequently, the animals were tested for the soluble liver antigen (SLA) antigen and recombinant Leishmania infantum chagasi antigens rP2a, rP2b, rP0, rHSP70, rHSP83, rH2A, and rKMP-11 using ELISA. The results demonstrate that the recombinant antigens that presented the best sensitivity, specificity, and high or moderate accuracy according to the Receiver Operating Characteristic (ROC) curves were rP2a, rP2b, and rH2A. These results indicate that rP2a, rP2b, and rH2A proteins are candidates for improving the diagnosis of CVL.

The family Anisakidae includes parasite genera that are important for public health due to their zoonotic potential. Among these, the genus Anisakis contains some of the most prevalent parasites found in fish that are consumed and commercially exploited in Brazil. Thus, this study aimed to investigate records of the presence of third-stage larvae of Anisakis spp. fish parasites found in Brazilian territory, focusing on their morphological, morphometric, biogeographic, and prevalence aspects over a period of 40 years. This analysis identified the presence of Anisakis larvae in 18 orders, 2 groups, 40 families, 60 genera and 69 species of infected marine, brackish and freshwater fish, demonstrating the lack of specificity to a particular group, which was also evident in the different morphometric data, as well as in the site of infection and habitat of the hosts, with predominantly marine fish being the most infected.. The presence of different Anisakis morphotypes highlights parasitic biodiversity and reinforces the need for taxonomic studies of these zoonotic agents found in fish consumed as food. Special attention should be given to the Amazonian ichthyofauna, located in one of the aquatic ecoregions considered a research priority in Brazil, with the identification of these zoonotic parasites being a matter of food security and public health.

This study aimed to identify larval forms of trematodes in Pseudosuccinea columella from rural properties with a history of bovine fasciolosis in the southern region of Espírito Santo, Brazil. A malacological survey was carried out on waterbodies from ten properties between June 2022 and March 2023. Aquatic snails were collected, identified, and evaluated for infection with trematode larvae by artificial photostimulation. The larvae found were morphologically characterized under a light microscope, and samples of the snails were subjected to histological analysis to observe larval trematodes in development in snails' tissues. A total of 678 specimens of P. columella were collected in nine properties, and larval trematodes were identified in 24 (4.08%) specimens from seven properties. A xiphidiocercaria morphotype, compatible with Haematoloechidae, was found in six properties. A morphotype of echinostome cercaria, compatible with the Echinostoma genus, was found in one property (2.17%). Larval Fasciola hepatica was not observed. Ecological studies are needed to investigate the environmental factors that may be related to the absence of natural infection of snails by F. hepatica, especially considering the presence of positive cattle in the evaluated properties. The data presented here reveal that P. columella a potencial vector role in the studied area.

Equine Piroplasmosis (EP) is a tick-borne disease caused by the protozoan parasites Babesia caballi, Theileria equi, and Theileria haneyi, characterized by intravascular hemolysis and associated systemic illness. Although T. equi and B. caballi have been widely reported in some regions of Brazil, data from other states are limited. Additionally, despite reports of T. equi genotype C, currently recognized as T. haneyi, has been identified in Brazil, there are no investigations using T. haneyi-specific molecular tools. This study assessed the presence of these three agents in horses from Baixada Maranhense microregion (n = 34), northeastern Brazil, and in horses from an equestrian center (n = 12) in Guará, southeastern Brazil. Of 46 horse DNA samples, one (2.1%) from an imported animal in the equestrian center tested positive for T. haneyi in ema-10 and ema-11-based PCR assays. Two animals tested positive for T. equi in a species-specific PCR (ema-1), and all samples were negative for B. caballi. BLASTn analysis showed ema-10 and ema-11 sequences shared 98.9% to 99.3% identity with T. haneyi detected in a horse at the U.S.-Mexico border. Despite the small sample size, this study confirms the presence of T. haneyi in Brazil and the need for monitoring imported animals.

The aim of this study was to report infection by Toxoplasma gondii in free-ranging mammals from Pantanal, as well as to compare the laboratory methods used to detect this parasite among native wildlife species. Blood samples from ocelots, crab-eating foxes, and coatis were included for serological analysis and molecular testing. In addition, tissue samples from wild rodents and jaguarundi were collected for molecular analysis. Seropositivity for T. gondii was 100% (2/2) in ocelots across all tests; ranged from 39.1% (9/23) by indirect hemagglutination assay (IHA) to 47.8% (11/23) by modified agglutination test (MAT) and indirect fluorescent antibody test (IFAT) in crab-eating foxes; and from 12.5% (3/24) by IHA to 20.8% (5/24) by MAT in coatis. The level of agreement between the serological techniques ranged from fair to moderate (Kappa=0.353-0.516). Furthermore, PCR analysis revealed the presence of T. gondii DNA in 100% (2/2 and 1/1) of the ocelots' blood and jaguarundi's brain, 30.4% (7/23) of the crab-eating foxes' blood, 45.8% (11/24) of the coatis' blood, and 23.8% (10/42) of the Thrichomys spp.'s tissues. Potentially atypical strains (incomplete genotyping) of T. gondii were identified by Restriction Fragment Length Polymorphism (PCR-RFLP) from ocelot, jaguarundi, and coati. These findings indicate the circulation of T. gondii among wild mammals at the Nhumirim Farm.

The aim of this study was to verify the prevalence of Trypanosoma vivax using hematological and molecular techniques and to evaluate possible associated risk factors in goats and sheep. A total of 192 animals from 14 farms in the municipalities of São Domingos and Valente da Bahia were used. Blood was collected from each animal to prepare stained blood smears and verify the presence of Trypanosoma spp. trypomastigotes testing and molecular (polymerase chain reaction [PCR], and sequencing). All blood smears were negative for trypomastigote forms of Trypanosoma sp. In the molecular analysis, nested-PCR detected 57.8% (111/192) of the samples as positive for Trypanosoma spp. and 10.9% (21/192) as positive for T. vivax using a specific primer. Sequencing indicated 97% - 99% similarity with catL of T. vivax. The use of shared needles was significant in the analysis of risk factors (p=0.049). Thus, T. vivax is present in small ruminants in Bahia, making it necessary for producers to be careful, especially when sharing needles, to avoid transmission between animals.

The objective of this study was to evaluate the hatching percentage of tick larvae of Amblyomma sculptum, Dermacentor nitens, Rhipicephalus linnaei, and three strains of Rhipicephalus microplus. The egg masses laid by females of each tick species were weighed in different amounts (125, 250 and 500mg), placed in adapted 3 and 5 mL syringes, and incubated at 27°C and 80% relative humidity for 25 days for A. sculptum and 21 days for the remaining species. After this period, larval hatching rate was evaluated and data were analyzed through correlation and comparison between groups. The results showed that the average hatching rates varied from 27.9% to 42.2% for A. sculptum, 86.6% to 87.7% for D. nitens, 74.4% to 80.0% for R. linnaei, and R. microplus: 75.3% to 82.6% (UFRRJ strain), 64.6% to 72.2% (Mozo strain), and 71.8% to 75.2% (Porto Alegre strain). Although statistically significant differences were observed in the mean percentages between groups, the correlation was weak. We concluded that the weight of the egg masses and the volume of the containers did not significantly affect larval hatching.

Although toxoplasmosis is well documented in New World non-human primates, data on its clinical impact and genotypic diversity in neotropical rodents remain limited. This study investigated fatal toxoplasmosis in Coendou spinosus through histopathological, immunohistochemical, and molecular analyses, with genotypic characterization of the infecting strain. Between September 2016 and October 2019, eight individuals were analyzed, including rescued animals and post-mortem cases from a local zoo in Southern Brazil. Tissue samples underwent histopathology and immunohistochemistry using anti-T. gondii antibodies, and molecular assays were conducted by nested PCR and PCR-Restriction Fragment Length Polymorphism (PCR-RFLP). Severe necrotizing lesions, especially in the central nervous system, were observed in five animals, associated with abundant bradyzoites and tachyzoites. Molecular detection confirmed T. gondii DNA in all animals, and subsequent genotyping revealed a previously undescribed atypical strain in the animal CS8. These findings demonstrate the high mortality associated with T. gondii infections, presenting documented clinical signs of toxoplasmosis in C. spinosus and highlighting its vulnerability to zoonotic pathogens, particularly due to habitat encroachment and increased interactions with humans and other wildlife.