Revista Brasileira De Parasitologia Veterinaria最新文献

Research into ticks that feed on small mammals is important because they can be vectors of pathogenic bioagents that infect animals and humans. In this study, small mammals were captured in the Maracanã Environmental Protection Area, in the eastern Amazon biome (São Luís, Maranhão), and were visually inspected to detect the presence of ectoparasites. Overall, 10 (48%) out of 21 small mammals were infested by ticks, as follows: three Didelphis marsupialis (30 Amblyomma sp. larvae, and 2 Ixodes sp. nymphs); three Monodelphis domestica (three Ixodes sp. nymphs) and four Dasyprocta sp. rodents (three Amblyomma sp. larvae, three Ixodes sp. nymphs and 16 Ixodes sp. larvae), making a total of 57 tick specimens. Two of the collected nymphs were molecularly identified as Ixodes bocatorensis, based on mitochondrial 16S rRNA gene partial sequences. Since all eight Ixodes sp. nymphs collected in this study presented the same morphotype, the molecular identification of two specimens as I. bocatorensis supports the identification of all collected nymphs as belonging to this same tick species. This study provides host records for immature stages of I. bocatorensis for the first time. Additionally, a brief morphological description of the I. bocatorensis nymph is provided.

This study reports the occurrence of a myxosporid parasite of the genus Ceratomyxa Thélohan, 1892 found in the gallbladder of Curimata cyprinoides Linnaeus, 1766. This species is abundant in the Tocantins-Araguaia hydrographic basin and holds environmental, social and economic importance. The genus Ceratomyxa is characterized by two equally-sized polar capsules with lateral projections, whick may appear slightly slightly arched in a half-moon shape or fully curved arched. Light microscopy and molecular analysis were employed in this study. The mature spores were composed of two equally-sized symmetrical valves with equal capsular foramina and two equally-sized lateral projections. These spores (n=40) were freely suspended in the gallbladder, with a total length of 11.2 ± 0.1 μm and width of 4.0 ± 0.3 μm. The polar capsules measured 2.1 ± 0.1 μm in both length and width; and the two symmetrical lateral elongations formed a posterior angle of 41.4º ± 0.7º. An integrated comparative analysis of the morphological characteristics and partial SSU rDNA sequences confirmed this finding as a parasite of the genus Ceratomyxa sp., located in the gallbladder of C. cyprinoides in the Tocantins-Araguaia basin, within the municipality of Araguatins, in eastern Amazon, Brazil.

Carcasses of road-killed wild animals provide critical insights into animal health and environmental conditions. However, data on the presence of lung parasites and their effects on the health of white-eared opossums are limited. This study examines lung parasites and their pathological effects on white-eared opossums (Didelphis albiventris) found in northern Paraná, Brazil. We collected and processed lung samples from 21 opossums using standard histological techniques. Lung nematodes were preserved and identified by their morphological traits. Heterostrongylus heterostrongylus (Travassos, 1925) was detected in nine animals (42.8%). Key histological observations included diffuse interstitial pneumonia, lymphoid tissue hyperplasia, pulmonary hemorrhage, smooth muscle hypertrophy in the pulmonary vessels, congestion, and edema. Although the immediate cause of death was hypovolemic or neurogenic shock from vehicular collisions, the findings underscore the significance of studying road-killed wild animals to evaluate wildlife health and environmental status. This research also documents the first instance of H. heterostrongylus lung infections in D. albiventris, suggesting that these parasites significantly impact lung health.

Gastrointestinal parasites found in four Neotropical psittacine birds of the species Ara macao, Amazona aestiva, Amazona vinacea and Pionus maximiliani have been reported. The carcasses of the animals were received from commercial breeders and a rehabilitation center for necropsy. In total, 589 parasites were collected during the exams and submitted for morphological analysis and taxonomic identification. Twenty parasites from each host were cleaned with lactophenol and analyzed by light microscopy, while four parasites from each host were prepared for scanning electron microscopy. Tissue samples were forwarded for histological analysis in search of erratic larvae; however, none were found. Parasites from A. macao, A. aestiva and A. vinacea were identified as Ascaridia hermaphrodita, whereas parasites from P. maximiliani were identified as Ascaridia columbae, promoting the first report of A. columbae in P. maximiliani. All birds were kept in enclosures with access to the ground, facilitating parasitism. Pionus maximiliani and A. vinacea were kept together in the same enclosure with high population density. Additionally, synanthropic animals, such as Columbiformes, were observed in the same enclosure, facilitating infection with A. columbae. The identification of Ascaridia species that parasitizes psittacine birds helps to improve prevention and control measures, thus enhancing avian health and welfare.

Bovine trypanosomiasis, caused by infection with the protozoan Trypanosoma vivax, is harmful to livestock worldwide. Knowing its epidemiology is relevant to evaluate the susceptibility, resistance, and tolerance of animals. The objective of this study was to determine the prevalence of T. vivax in Crioula Lageana cattle and relate them to clinical, hematological, and biochemical findings to elucidate the breed's health and disease tolerance characteristics. Venous blood samples from 310 bovines considered healthy during the clinical examination were used to perform polymerase chain reaction (PCR) analysis, Immunofluorescence Antibody Test (IFAT) assays, hemogram tests, and serum biochemistry. The collected data were subjected to statistical analyses to compare seropositive and negative groups. IFAT indicated that the seroprevalence for T. vivax was 8% (24/310); however, all tested animals were negative in the conventional PCR (0%, 0/310). Higher amounts of platelets and less cholesterol were detected in seropositive animals but were within the reference values. Ruminal hypomotility and mild tachycardia were observed in all sampled animals. Considering the non-specific clinical signs and the absence of hematological alterations in infected animals, the seropositivity found indicates previous exposure to the protozoan, and the absence of clinically affected animals may result from characteristics inherent to this breed.

The classification of eukaryotic organisms has evolved significantly over the past years. For a long time, the five-kingdom model proposed in 1969, which included the kingdoms Monera, Protista, Fungi, Plantae, and Animalia, dominated biological classification. However, recent advances in molecular biology, particularly phylogenomic studies, have challenged this classification as it does not accurately represent the evolutionary patterns of a vast diversity of organisms, especially those formerly known as protozoa. Currently, Protista is no longer considered a valid taxon, as the organisms previously classified in this group are highly divergent and not monophyletic. Modern approaches now classify eukaryotes into several supergroups, with "protozoa" now dispersed among different groups. For example, parasites once grouped as "protozoa," such as Babesia (Apicomplexa), Trypanosoma (Euglenozoa), and Entamoeba (Evosea), are now placed into distant branches of the tree of life and within different supergroups. Although this supergroup classification may change in the coming years, it provides a more accurate representation of evolutionary relationships among eukaryotes. However, this issue has not been adequately discussed by the veterinary parasitology community. This article advocates revisiting these terms in light of modern classification systems to ensure a more accurate and biologically realistic terminology that reflects current knowledge.

The present study described the morphological characteristics of myxospores of cnidarians belonging to the class Myxozoa at different infection sites in Pygocentrus nattereri Kner 1858 (Characiformes: Serrasalmidae), found in Lake Sacaizal, in the municipality of Pracuúba, state of Amapá, Brazil. In 44% of the specimens analyzed, myxospore gill filaments of the genus Henneguya were observed with a pyriform sporal body, presenting long caudal projections internally, with two polar capsules. In some filaments, branchial arches, and fin cysts (with a prevalence of 22%) pyriform Myxobolus myxospores were observed, which were larger than those found in the caudal kidneys, where the myxospores had an elliptical shape, demonstrating the presence of two morphotypes in the same host. Thus, these morphological data contribute to the diversity of myxozoans in Amazonian fish, particularly P. nattereri in their natural environment, with the first occurrence of these parasite genera in this host.

The objective of this study was to determine the prevalence of Babesia bigemina infection and associated risk factors in Crioula Lageana cattle, a Brazilian native breed known for its tick resistance. Blood samples were collected from 311 registered cattle (62 males, 249 females) from conservation nucleus properties in Santa Catarina State, Brazil. Samples underwent DNA extraction and nested PCR targeting the rap-1a gene for B. bigemina detection. Animals were categorized by sex, age class, and tick presence during sampling. An epidemiological questionnaire assessed potential risk factors. The overall B. bigemina prevalence was 60% (186/311; 95% CI: 56,95%-62,67%). Males showed significantly higher infection rates (79%; 49/62) compared to females (55%; 137/249; OR=3.36, p<0.001). Bulls (81%; 26/32) and calves (78%; 56/72) exhibited higher infection rates than cows (50%; 70/141) and heifers (52%; 34/66; p<0.001). Tick presence during sampling increased infection probability (OR=2.00, p=0.006). Contact with other animal species (OR=1.57, p=0.037) and regular veterinary care (OR=6.77, p=0.009) were identified as significant risk factors. Results indicate enzootic instability in the studied population, with distinct sex-based susceptibility patterns. These findings provide baseline data for developing targeted control strategies for B. bigemina in Crioula Lageana breeding programs.

Leishmaniasis is a parasitic disease caused by Leishmania spp., transmitted to hosts through the bite of female phlebotomine sandflies, with domestic dogs serving as reservoirs for the disease. Understanding the entomofauna is crucial for effective control of vector-borne diseases, such as leishmaniasis, because various environmental and climatic factors can influence sandfly presence and distribution. This study aimed to conduct a quantitative and qualitative survey of the entomofauna in urban and peri-urban areas of Lages, Santa Catarina, Brazil, and to analyze documented cases of canine leishmaniasis in the city, in response to the rising number of non-autochthonous cases in dogs. The lack of prior studies on this fauna in the municipality raises concerns for public health services. Nine areas were monitored over the course of one year, and clinical and epidemiological records of canine leishmaniasis in the city were analyzed. A total of 10,638 insects were collected, with no phlebotomine sandflies identified. All evaluated cases of canine leishmaniasis were classified as non-autochthonous based on the movement history of these animals and the absence of the disease vector in the municipality. This information may guide further control and prevention measures for leishmaniasis in the region, aligned with a One Health perspective.

The objective of this study was to describe the positivity of intestinal parasitosis in cats from the city of Jataí, Goiás, as well as to determine the accuracy of different parasitological techniques applied. 120 samples were collected, 64 from household cats and 56 from stray. The parasitological techniques of Willis, Sheather, Faust, Hoffman-Pons-Janer-Lutz and Rugai staining were then performed. The positivity rate of endoparasites in the analyzed samples was 19.2%, with a predominance of hookworm eggs. Cystoisospora spp. and Hammondia hammondi oocysts were also found, with a case of co-infection with the two species. No statistical difference in positivity was found between household and stray cats. However, a significant difference was found upon evaluating sex and neutering status, revealing that male cats and non-neutered animals showed higher positivity rates, with 28.8% of non-neutered animals testing positive compared to 9.83% of neutered animals. The Willis technique was considered the gold standard for hookworm diagnosis, with a sensitivity of 91.3%. While the Willis technique was identified as the gold standard for detecting hookworm eggs, the evaluation of other methodologies demonstrated that the integration of techniques can improve the detection of various parasitic stages.