Revista Brasileira De Parasitologia Veterinaria最新文献

Haemosporidians belonging to the subgenus Haemoproteus (Parahaemoproteus) and the genus Leucocytozoon rely on dipteran vectors for transmission, with biting midges (Culicoides spp.) and black flies (Simuliidae), respectively, playing essential roles in their life cycles. However, little is known about the potential role of Culicoides species as vectors for haemosporidians outside Europe and Asia. This study aimed to investigate the presence of Haemoproteus spp. and Leucocytozoon spp. DNA in Culicoides spp. from the Brazilian Amazon. A total of 345 midges (95 Culicoides foxi, 218 Culicoides hylas, and 32 Culicoides leopoldoi) were collected between February 2022 and February 2023 in the Amazon National Park, Pará. Specimens were morphologically identified, and DNA was extracted using the TRIzol technique. PCR targeting the endogenous cox-1 gene confirmed successful DNA extraction in 86.7% (299/345) of samples. Nested PCR assays targeting the cytB gene of Haemoproteus spp. and Leucocytozoon spp. did not detect DNA in any sample. The absence of detection suggests that the sampled Culicoides species are unlikely vectors, possibly due to feeding preferences or ecological limitations. Future studies targeting both DNA and sporozoites in salivary glands of engorged female Culicoides spp. are needed to clarify the vectors involved in the transmission of haemosporidians.

Lice are obligatory ectoparasites of birds and mammals, possessing mouthparts adapted for feeding on the blood and/or keratinized tissue of their hosts. Recording parasites that may cause economic and sanitary losses in the country's poultry industry is of utmost importance. For this reason, in the present study, we report the first record of Lipeurus caponis (Linnaeus, 1758) parasitizing domestic chickens in the Brazilian Amazon, specifically in the municipality of Autazes, state of Amazonas. The insect was collected using entomological forceps and deposited in a 1.5 ml microtube containing absolute ethanol on a rural property located on the banks of the Paraná Madeirinha River, where chickens are raised in a colonial system, coexisting with animals of different species and fed a diet based on whole corn grains. A male specimen of L. caponis was collected from the interscapular tract during the rainy season. Given this finding, we highlight the importance of entomological surveillance to prevent potential epizootic outbreaks and mitigate impacts on regional poultry production.

This study investigated the presence of Rickettsia spp., Ehrlichia spp., Anaplasma spp., and Borrelia spp. DNA in questing ticks collected from a forest fragment under constant anthropogenic pressure in the state of Pará, Brazil. The fragment was divided into three zones: interior, edge, and surrounding matrix. Ticks were collected in all zones using flannel drag sampling, flannel leggings, and CO2-baited traps. Nymphs and adults were morphologically identified using taxonomic keys, while larvae were subjected to molecular identification. DNA extracted from the ticks was tested for the target pathogens using polymerase chain reaction (PCR). In total, 561 questing ticks (525 larvae, 29 nymphs, and 7 adults) were collected, representing eight species: Amblyomma cajennense sensu stricto, Amblyomma calcaratum, Amblyomma geayi, Amblyomma goeldii, Amblyomma humerale, Amblyomma naponense, Amblyomma pacae, and Amblyomma varium. Rickettsia bellii was detected in one A. varium larva and one A. goeldii larva. All samples tested negative for Ehrlichia spp., Anaplasma spp., and Borrelia spp. This is the first report of R. bellii in A. varium and A. goeldii in Brazil.

This study reports the first record of parasitism of Ixodes luciae Sénevet, on the marsupial Marmosops noctivagus (Tschudi), in Brazil and in South America. The tick I. luciae, previously recorded in Brazil in the Amazonas state, was collected from the marsupial using a flight intercept trap suspended 28 meters above ground, at the canopy level, in an area located 60 km north from Manaus, Amazonas, Brazil. It is the first time this marsupial has been collected with this type of trap, representing a bycatch collection. Both records highlight significant contributions to better understanding host-parasite interactions and the biodiversity of the Amazonian ecosystem. Both 18S rRNA and 16S rRNA sequences showed 100% identity with previously available I. luciae sequences. Molecular analysis did not indicate the presence of Rickettsiales agents in I. luciae.

The genus Amblyomma has the largest number of tick species in the Neotropical region. Amblyomma ovale displays high ecological plasticity and can be found in different habitats and a variety of vertebrate hosts. Small mammals of the family Echimyidae have been identified as hosts for this species. However, studies investigating their role as hosts of these ticks in the Amazon region are lacking. The present study aims to record the parasitic association between A. ovale and a Echimyidae species (Proechimys cuvieri) in the extreme north of the Brazilian Amazon, providing information about the research of potentially pathogenic organisms. Eight nymphs were collected and subjected to taxonomic and molecular identification, and pathogen screening was performed on the family Anaplasmataceae agents and the genera Bartonella, Coxiella, Hepatozoon, Mycoplasma, and Rickettsia. All the ticks were identified morphologically and molecularly as A. ovale, but PCR assays for pathogen detection showed no positive results for the target genes. This is the first time that A. ovale has been associated with P. cuvieri.

Third-stage larvae of a nematode species were found encapsulated in the cephalothorax of Macrobrachium amazonicum from the Guamá River, municipality of Belém, in the state of Pará, northern Brazil. Of a total of 120 specimens of M. amazonicum that were caught, 15.8% were parasitized with Cystidicolidae larvae that had morphological characteristics compatible with the genus Pseudoproleptus, such as rounded cephalic end, two pseudolips, slit-shaped buccal opening with four large submedian lips, vestibule with prostom and conical tail with a small mucron. The low presence of Pseudoproleptus larvae did not affect the growth of the shrimp, but these results cannot be generalized since the sampling was relatively low. Therefore, so the occurrence of this nematode could still negatively affect the growth and reproduction of these shrimp, leading to their death, which could directly affect their population dynamics and consumption by the Amazonian riverside population. Finally, we recommend more analyses with a greater sampling effort.

The Serra da Canastra National Park is a Conservation Unit where domestic dogs live near populations of maned wolves (Chrysocyon brachyurus). Recognizing the importance of parasitic diseases in endangered species such as the maned wolf, our research objective was to identify and determine the prevalence of parasites in fresh fecal samples collected in January and July 2021 from both canids that inhabit the region. The dog feces were collected after the administration of a 5% glycerin enema and evacuation, while the maned wolf feces was collected along the park's roads. For diagnosis, Sheather's and Hoffman, Pons and Janer (HPJ) parasitological techniques were applied. Among the dog samples, 22.5% (9/40) tested positive for at least one parasite species, mainly 44.4% (4/9) to hookworm eggs, 22.2% (2/9) to Toxocara sp. and 11.1% (1/9) to Cystoisospora sp. and trematode eggs. Among maned wolves, 75% (30/40) of samples were positive to capillariid eggs with 86.6% (26/30), followed by 16.6% (5/30) to Toxocara sp., 10% (3/30) to hookworm eggs and Dioctophyma renale, 6.6% (2/30) to Cystoisospora sp., trematode eggs and spirurid eggs, 3.3% (1/30) to Physaloptera sp. and acanthocephalan eggs.

We analyzed the distribution of endoparasites in five species of Hylidae frogs during their reproductive period, aiming to understand how the host's habitat influences the parasites. Five anuran species (Boana raniceps, Pithecopus azureus, Pseudis platensis, Scinax acuminatus and Scinax nasicus) were sampled in temporary and permanent ponds in Nhecolândia Pantanal, Brazil. A total of 276 individuals were collected, 43.84% of which were parasitized by endoparasites. Metacercariae of Diplostomidae gen. sp. were predominant, accounting for 85.94% of the total parasites found. Nematodes and cestodes were also identified, with nematodes representing 7.85% of the total parasites. Statistical analyses indicated that host body size was not a significant predictor of parasitism probability, although a weak negative correlation between host body size and parasite abundance was observed. Network analysis revealed a modular structure in the parasite-host interactions, with moderate connectivity. These results suggest that environmental factors, particularly those related to the aquatic habitats of anurans, play a fundamental role in shaping parasite community structure. This study provides important insights into the complex ecological interactions between anurans and their parasites, significantly contributing to the understanding of parasite-host interaction dynamics in the Pantanal ecosystem.

Although previous studies have identified Ehrlichia canis, Anaplasma platys, Babesia vogeli, and Hepatozoon canis in dogs in Northeastern Brazil, research on their presence within and around environmental conservation units remains scarce. The present study investigated the presence of tick-borne pathogens in domestic dogs in the rural region of Baraúna, within the buffer zone of the Furna Feia National Park (FFNP), an environmental conservation unit in the Caatinga biome of Rio Grande do Norte, northeastern Brazil. Blood samples from 52 dogs were collected to detect the presence of A. platys (16S rRNA), B. vogeli (18S rRNA), E. canis (16S rRNA), and H. canis (18S rRNA) DNA by Polymerase Chain Reaction (PCR). More than 90% of dogs were found to be infected with at least one pathogen, predominantly E. canis and H. canis. Co-infections (38.5%) and multi-infections with three (19.2%) and four (5.8%) pathogens were also frequent and diverse, underscoring the complexity of tick-borne diseases in this region. These findings highlight the epidemiological importance of dog-associated pathogens, and raise concerns regarding their potential transmission to wildlife within the conservation unit, as some of these pathogens have been previously described in wild mammalian species inhabiting the FFNP, including endangered species.

The hemoprotozoan Trypanosoma evansi is a parasite that infects mammals, causing an infection known as trypanosomiasis. There is no report of T. evansi in horses in the State of Maranhão, highlighting the need to assess exposure and infection by the parasite and generate data for its monitoring. The objectives of this study were to identify T. evansi in blood samples from horses, investigate its occurrence in horses in this region, and analyze the associated risk factors. Three hundred blood samples were collected for parasitological (blood smear), serological (indirect enzyme-linked immunosorbent assay - ELISA), and molecular (polymerase chain reaction - PCR) diagnostic purposes. No trypomastigote forms of T. evansi were observed in the examined blood smears. Serological examined of 209 samples revealed that 33.01% (69/209) were positive for anti-T. evansi antibodies. No variable was identified as a risk factor. Among the 300 samples submitted to PCR, 1% (3/300) were positive, and sequencing showed 100% similarity with T. evansi species. The study identified exposure and infection of horses by T. evansi in Maranhão, expanding its geographic distribution in the country and highlighting the importance of periodic testing.