Revista Brasileira De Parasitologia Veterinaria最新文献

The Hepatozoon genus is composed of hemoparasites widely distributed, though their diversity and phylogeny remain poorly understood in the Brazilian herpetofauna. We aimed to characterize Hepatozoon species infecting the blood and spleen of amphibians and reptiles in Mato Grosso, Midwestern Brazil, using morphological and molecular tools. In total, 146 animals from 19 species (8 amphibians and 11 reptiles) were evaluated. Giemsa-stained blood smears revealed Hepatozoon-like inclusions in 35 individuals (8 amphibians and 27 reptiles), including new infection records in the anurans Boana raniceps and Trachycephalus typhonius, and the snake Eunectes notaeus. Morphological analysis revealed diverse morphotypes. Molecular analysis of the 18S rRNA gene identified six haplotypes in Rhinella diptycha, Ameiva ameiva, Boa constrictor, Epicrates crassus, E. notaeus, and Caiman yacare. Phylogenetic analyses revealed clustering with clades linked to H. musa and H. caimani, suggesting the presence of potentially novel lineages. These findings highlight the high genetic diversity of Hepatozoon in the region and emphasize the value of integrative approaches in parasitological research.

This study investigated the presence of Anaplasma platys, Babesia vogeli, Ehrlichia canis, and Hepatozoon canis in dogs in Mossoró, Rio Grande do Norte, Brazil, from October 2022 to August 2023. Blood samples were collected from 181 dogs with suspected hemoparasitoses based on clinical and/or laboratory findings (such as hematological alterations) for direct hemoparasite examination on slides, polymerase chain reaction (PCR), and phylogenetic analysis. PCR revealed that 72.3% of dogs were infected with at least one agent. Among these, 44.7% were monoinfected and 27.6% coinfected, with 21.5% infected by two agents and 6.1% by three or more. E. canis was most frequent (41.9%), followed by H. canis (35.4%), A. platys (21.5%), and B. vogeli (7.7%). Anaplasma and Ehrlichia-like morulae, Hepatozoon sp. gametocytes, and Babesia sp. merozoites were found in 20.0%, 11.1%, 15.0%, and 1.7% of animals, respectively. Phylogenetic analysis of 16S and 18S rRNA gene sequences revealed high similarity to reference strains from Brazil and other countries. The infection patterns underscore the importance of diagnostic and preventive measures to safeguard animal health in areas endemic for Rhipicephalus sanguineus sensu lato (s.l.), given the frequency of coinfections that may exacerbate clinical signs and hinder treatment.

Anaplasma marginale is an obligate intraerythrocytic alpha-proteobacterium that causes bovine anaplasmosis, which is responsible for economic losses in the livestock industry worldwide. Although the mechanism of A. marginale infection in tick cell lines has been extensively studied, replication dynamics have not been investigated so far. This study presents the replication kinetics of A. marginale in the RBME-6 tick cell line derived from Rhipicephalus microplus over time. Cell cultures were infected with corpuscles of A. marginale isolated from bovine blood. The replication curve was generated by the number of copies of the msp1β gene obtained by reverse-transcription quantitative PCR (RT-qPCR) using complementary DNA (cDNA) synthesized from RNA. An initial lag phase and an exponential replication phase were recorded. A subsequent death phase was observed, with rapidly decreasing numbers of A. marginale msp1β copies. The surviving population of A. marginale entered a long-term stationary phase from 13 dpi until 29 dpi. Light microscopy was used to monitor the infection in the cells. The propagation kinetics of A. marginale in RBME-6 cells were shown to be essential for guiding future studies aimed at unraveling the crosstalk between this bacterium and its biological tick vector.

Growing antiparasitic resistance challenges parasite control in livestock, increasing interest in natural product-based alternatives for animal health and food quality. This study evaluated the in vitro activity of Lippia origanoides essential oil against Rhipicephalus microplus, Haemonchus contortus, and Caenorhabditis elegans. Fresh leaves of L. origanoides from Maranhão, Brazil, were used to obtain essential oil by hydrodistillation, and its chemical composition was determined by gas chromatography-mass spectrometry (GC-MS). Bioassays evaluated activity against R. microplus larvae (immersion and repellency), H. contortus eggs (hatch inhibition), and C. elegans adults (mortality), all using serial dilutions of essential oil. Experiments were performed in nine replicates, and results were analyzed by nonlinear regression. Chemical analysis of the oil revealed the main constituents: camphor (32.13%), β-bisabolene (10.02%) and camphene (6.66%). The larval immersion test of the oil showed an LC50 (letal concentration) of 7.48 mg/mL against ticks. A repellency assay revealed an RC50 (repellent concentration) of 0.058 mg/cm2 at 10 minutes. The egg hatch assay for H. contortus resulted in an LC50 of 0.67 mg/mL, whereas the adult mortality assay for C. elegans showed an LC50 of 2.23 mg/mL. These results suggest the acaricidal, repellent, and nematicidal efficacy of essential oil of L. origanoides.

Cystic echinococcosis (CE) diagnosis relies on clinical signs, serological tests, radiological findings and histopathology. Lack of pathognomonic features or clinician inexperience can make CE diagnosis challenging. In this study, we aimed to investigate the demographic, serological, and radiological characteristics of individuals with a preliminary diagnosis of CE. A total of 1,410 serum samples from 1,265 patients were analysed for the presence of IgG antibodies Anti-Echinococcus granulosus IgG using chemiluminescence immunoassay (CLIA) and indirect haemagglutination assay (IHA). Among these, 148 samples showed serological and radiological findings compatible with CE. Echinococcal cysts were confirmed by ultrasonography, computed tomography, or magnetic resonance imaging. Among the 148 patients compatible with CE, 88 were women (59.5%) with a mean age of 45.0 ± 19.1 years, and 60 were men with a mean age of 35.4 ± 18.3 years. Although there was no significant difference between the sexes regarding the number, location, size, or complications, the mean age of female patients was higher than that of male patients. Our findings suggest that radiological methods are essential for assessing cyst size and activity, while serological methods provide complementary diagnostic value and contribute to generating important epidemiological data. As CE is a zoonosis, collaboration with veterinary surveillance is essential for effective control.

Parasites of the phylum Apicomplexa are among the main etiological agents of diseases in vertebrates and invertebrates, including humans and domestic animals. In the present study, 18 specimens of Pygocentrus nattereri (red piranha) captured in Lagoa do Sacaizal, municipality of Pracuúba, state of Amapá, were analyzed. Of these, 6 (33%) had whitish spots on their liver lobes. Clusters of Calyptospora sp. oocysts measuring 18.1 ± 0.5 (17.4-18.7) µm in diameter, with four pyriform sporocysts measuring 9.0 ± 0.45 (8.3-9.8) µm in length and 4.3 ± 0.50 (3.7-5.1) µm in width, each with two sporozoites. Histopathological evaluation indicated the presence of oocysts adjacent to blood vessels and in the hepatopancreas, promoting necrosis, degeneration, and tissue fibrosis associated with inflammatory infiltrate and melanomacrophage bodies. This is the first record of coccidia parasitizing P. nattereri.

Cutaneous larva migrans (CLM) and visceral larva migrans (VLM) are neglected zoonoses caused by Ancylostoma spp. and Toxocara spp. Although investigations have been conducted in some areas of São Paulo State, Brazil, the presence of these helminth eggs in domestic carnivores' feces from public areas in Jaboticabal (SP) had not previously been studied. This study aimed to detect Ancylostoma spp. and Toxocara spp. eggs in fecal samples collected in public squares using the Willis-Mollay method and to assess the community's knowledge related to public health topics through a structured questionnaire. A total of 88 fecal samples were collected in 32 localities of the city, of which 12.5% (11/88) were positive for eggs of Ancylostoma spp. and none for Toxocara spp. The answers to the questionnaire revealed a direct trend between education level and knowledge of zoonotic risks, indicating that limited knowledge can be associated with a greater exposure to infection. This is the first study to report the presence of Ancylostoma spp. eggs in domestic carnivores' feces in Jaboticabal. The results highlight the risk of CLM and reinforce the need for epidemiological surveillance in dogs and cats, along health education initiatives to promote regular deworming and the diagnostic testing of pets.

Fish aquaculture is one of the main food production sectors for the growing global human population and is currently one of the most profitable production activities. However, parasitic infestations have emerged as a significant factor influencing fish aquaculture production, negatively impacting the profitability of this food production activity. This study aimed to report the mutilation of pirapitinga Piaractus brachypomus gill filaments caused by a Cymothoidae parasite. In April 2022, Piaractus brachypomus were examined at a fish farm in Macapá, state of Amapá, Brazil. The host fish were analyzed, and the parasite found was preserved in 70% ethyl alcohol for taxonomic identification. Of the 31 fish examined, one had its gills infested with a crustacean parasite identified as Braga patagonica. A female parasite caused macroscopic mutilation of the filaments on the four right gill arches of P. brachypomus and severe damage at the attachment site. This is the first record of B. patagonica infestation in P. brachypomus. The fish farming water supply allowed the isopod ectoparasite to pass from wild fish to the pond, where it consequently found favorable conditions in the host fish.

Fasciolosis is a foodborne anthropozoonotic disease caused by Fasciola spp. that affects multiple hosts worldwide. Genetic characterization studies have revealed considerable diversity within F. hepatica populations owing to human and animal migration and intermediate snail hosts. Molecular markers such as microsatellites and mitochondrial DNA sequences are useful tools for assessing parasite population dynamics and evolutionary history. In this study, 16 F. hepatica samples were analyzed using cytochrome c oxidase 1 (CO1) and nicotinamide dehydrogenase (NADH) genes. Parasites were collected from the livers of naturally infected cattle originating from 14 municipalities in Paraná, Brazil. Both CO1 and NADH sequences showed high homogeneity, with mean genetic distances <1% (0.0084 and 0.0092, respectively). Network analyses revealed seven CO1 haplotypes and four NADH haplotypes among the new Paraná samples. When compared with reference sequences available in GenBank from other Brazilian states (Rio Grande do Sul and São Paulo), the Paraná samples also displayed <1% genetic divergence. This high level of homogeneity suggests a common and stable origin, with limited gene flow across regions. The genetic information reported here can support the development of targeted interventions, such as vaccines and drugs, aimed at controlling similar F. hepatica genetic variants.

This study examines the presence of gastrointestinal parasites in fecal samples from free-ranging jaguars (Panthera onca) in the Pantanal biome and assesses their potential as bioindicators of environmental health at the human-animal interface using a noninvasive approach. In 2024, ten fresh fecal samples were collected from the ground at Piuval Lodge in the northern Pantanal, state of Mato Grosso, Brazil. All samples were morphologically consistent with large felids, suggesting a high likelihood of originating from jaguars, based on field evidence. Coproparasitological analysis using sedimentation and flotation techniques identified Spirometra spp. eggs, with a positivity rate of 100%. Additionally, 20% of the samples tested positive for Toxocara spp. and one sample was positive for the genus Ancylostoma. This study highlights that jaguars (Panthera onca) are a potential bioindicator of environmental health and a sentinel species in the Pantanal, thus emphasizing the interaction between wildlife, domestic animals and human activities.