Revista Brasileira De Parasitologia Veterinaria最新文献

Didelphis marsupialis is a marsupial species that effectively adapts to synanthropic processes developing in cities. This marsupial lives closely with domestic animals and humans, which has favored the active exchange of parasites, thus increasing polyparasitism. Hence, this study aimed to determine the prevalence of helminths and protozoans infecting D. marsupialis in the Corregimiento of Santa Elena, Medellín. Twenty-three individuals were captured and classified as male, female, adult, or juvenile. The fecal samples were analyzed using various coprodiagnostic techniques. The eggs and oocysts were identified by microscopic evaluation of their morphology and morphometry. Twelve parasite species were identified: nine nematodes, one acanthocephalan, and two protozoans. In addition, an Adeleid coccidia considered pseudoparasite was found. The most prevalent parasite species (>50%) were Eimeria sp, Cruzia sp., Aspidodera sp., and Gnathostoma turgidum, and nematode larvae. No significant differences were observed between parasite prevalence and host sex or age. Parasites of public health interest, such as Trichuris spp., Capillariidae nematodes, Strongyloides spp., and Giardia spp., were also identified. This study confirmed that the urban habitat of the opossum has a high frequency and diversity of endoparasites, some of which have been reported for the first time in Colombia.

Aplectana comprises species of gastrointestinal helminths commonly found parasitizing amphibians and reptiles worldwide. However, most species of the genus are described based only on morphological traits. During helminthological surveys, we found nematodes identified as Aplectana pella parasitizing the hylid frog Osteocephalus cabrerai from the same locality as the original description. We provided the first nucleotide sequence of ribosomal gene 18S rDNA for Aplectana pella and established the species' phylogenetic position between representatives of Cosmocercidae. A pairwise genetic comparison between A. pella and its congeners revealed a low genetic divergence. We found that our sequences clustered with species of Cosmocerca, reinforcing the hypothesis that representatives of the genus Aplectana do not form a monophyletic group.

[This corrects the article doi: 10.1590/S1984-29612024001].

Species of the chewing louse genus Neopsittaconirmus Conci, 1942 are host-specific parasites on Old World and Australasian parrots (Psittaciformes), infesting both wild and captive birds. Despite veterinarian practices that attempt to eliminate parasites from captive hosts, two species, Neopsittaconirmus gracilis Guimarães, 1974 and Neopsittaconirmus vendulae Sychra, 2006, frequently infest captive birds, not only their regular natural hosts, but also other species that are not naturally parasitized. Here we report and discuss additional records of these two species of lice from captive parrots in Brazil, Australia, England, Réunion and the United States of America.

Opossums are synanthropic animals that participate in the zoonotic transmission cycles. Chagas disease, a neglected tropical disease caused by Trypanosoma cruzi, affects many domestic and wild animals and humans worldwide. This study aimed to determine the occurrence of T. cruzi in free-ranging opossums in Canoinhas, Santa Catarina, Brazil. Fifty opossums (Didelphis albiventris) (33 captured and 17 road-killed) were evaluated using Nested-PCR assay. All tissue samples were negative (0/17). Eight of the 33 (24.24%; 95% CI:11.94-40,89%) blood samples were positive for T. cruzi. No significant associations were found between the sex (male/ female, p = 0.423), the trap area (rural/urban, p = 0.163), and positivity for T. cruzi in opossum blood samples. All samples showed 100% identity with T. cruzi (KF788250) isolated from Panstrongylus megistus in São Paulo, Brazil. The phylogenetic analysis model allocated all sequences obtained from D. albiventris to the large TcI clade of T. cruzi. This study provides the first record of T. cruzi in white-eared opossums in Canoinhas, Santa Catarina, southern Brazil.

In this study, an evaluation was made of three treatments against feline leishmaniosis (FeL) and their impacts on the transmission of Leishmania infantum to its vector, Lutzomyia longipalpis. A cat with clinical signs of FeL was examined and L. infantum diagnosed. Subsequently, the cat was subjected to xenodiagnosis and L. infantum detected in the vectors. The cat was then treated with three different drugs and the clinical improvement and parasite transmissibility to the vector were evaluated. Promastigotes were observed in 21/52 female sandflies (40.38%) in a xenodiagnosis prior to the treatments. Clinical signs persisted after the first treatment with marbofloxacin, and the cat remained positive in serological, molecular, and parasitological tests. Therefore, the cat was treated with miltefosine but remained sick and tested positive. A second xenodiagnosis was performed a month after treatment with miltefosine, and promastigotes were observed in 5/9 females (55.55%). Lastly, the cat was treated with allopurinol, which led to good clinical improvement, but it remained positive, and a final xenodiagnosis revealed Leishmania in 2/29 (6.89%) females. The results showed that only treatment with allopurinol produced a good clinical response, but none of the treatments succeeded in eliminating L. infantum infection or preventing transmission to the vector.

A complex interaction of gastrointestinal parasites with sheep hosts may involve bacteria communities, parasite genera, parasitic genes, and biological pathways. Haemonchus contortus presents a global challenge for ruminants, and the bacterial community can influence sheep's resistance and susceptibility to these parasites. Thus, a better understanding of this complex interaction could contribute to the development of a new approach to parasite control. This study evaluated the bacterial community of Corriedale sheep naturally infected with H. contortus based on the fecal egg counts over ten months and then classified as having low (LC), intermediate (IC), or high (HC). Stool samples were collected monthly for egg counts (EPG), and 16S rRNA gene sequencing was performed on five animals from each group. The average EPG was 2,635 ± 105 for HC, 845 ± 129 for IC, and 110 ± 70 for LC, with a significant difference (p = 0.0001). Firmicutes, Proteobacteria, and Spirochaetes were more abundant in the HC group. 102 bacterial genera showed significant differences between the LC and HC groups. Beta diversity was statistically different (p<0.005) for HC compared with the other two groups; also, different communities were found between LC and HC. Sediminispirochaeta, Oribacterium, Alloprevotella, Prevotellaceae_UCG-001, Prevotellaceae_UCG-003, Ruminiclostridium_6 and Ruminococcus_1were significant more abundant in LC, and IC group. Acetobacter and Methanocorpusculum had a significant reduction in the LC group. Thus, bacterial genera related to low methane emission and food efficiency were significantly present in the LC group. Therefore, a better understanding of the role of host-bacterial community-parasite interaction could contribute to improving parasite control management.

This study investigated infection by Leishmania spp., Leptospira spp., Toxoplasma gondii, and Trypanosoma cruzi in six-banded armadillos (Euphractus sexcinctus) from the semiarid region of northeastern Brazil. Twenty specimens of E. sexcinctus were captured alive by wildlife veterinarians from their natural habitats in different locations. The animals were euthanized following induction of anesthesia, and different biological samples were collected. Infection with four pathogens was subsequently evaluated: Leishmania infection was investigated by spleen and liver Polymerase Chain Reaction (PCR); Leptospira spp. infection was evaluated by kidney PCR and serologically by microscopic agglutination test; T. gondii infection was assessed by PCR of the heart, lung, and spleen; and T. cruzi infection was investigated by heart and whole blood PCR and hemoculture. All tests presented negative results apart from whole blood PCR to detect T. cruzi, which was positive in one of the 20 animals tested and confirmed by genetic sequencing. It is important to highlight that this is the first study comprising a molecular investigation of different zoonotic pathogens in six-banded armadillos, and the findings reported here bring new and important knowledge regarding zoonotic diseases in this species.

This study evaluated dynamics of antibodies in dogs treated for canine visceral leishmaniasis (CVL). Twenty-one dogs naturally infected by Leishmania spp. were grouped based on the treatment protocol: G1 (n=4) received allopurinol; G2 (n=10) allopurinol with miltefosine; and G3 (n=7) allopurinol, miltefosine and Leish-Tec® vaccine. The dogs were monitored monthly for a period of one year. To verify serum antibody titers, an indirect immunofluorescence reaction was performed. We found that dogs from G1 and G2 had lower clinical scores and antibody titers, when compared to the parameters evaluated in pre-treatment; however, clinical relapses were observed in three animals. In G3, clinical scores were lower than pre-treatment; however, they presented relatively stable antibody titers and no clinical relapse was observed. All animals submitted to the evaluated treatment protocols showed relative improvement in clinical signs. Furthermore, the immune response of animals must be considered, given the challenges of parasitic loads in infections. Therefore, it is necessary to complement the methods of clinical and therapeutic monitoring of dogs with CVL in order to establish the risk of transmissibility of the agent in infected and treated dogs.

The tucunaré (Cichla sp.) is an Amazonian fish that is heavily commercialized in the state of Amapá, and it can be infected by a variety of parasites, including coccidia of the genus Calyptospora, which are identified at the genus level by analyzing the structures that comprise its morphology. This study aimed to describe the morphology and histopathology of Calyptospora sp. parasitism in Cichla monoculus Spix, 1929 in the Municipality of Pracuúba, Amapá, Brazil. Nine specimens were acquired from the Lake Sacaizal by artisanal fishermen and transported in isothermal boxes to the Integrated Morpho-molecular and Technologies Laboratory (LIMT) of the Federal Rural University of the Amazon in Belém, Pará, where they were necropsied. Fragments of the liver were removed to visualize cysts using light microscopy and processed for scanning electron microscopy and histology analyses. The analysis revealed that 66.6% of the fish examined had clusters of oocysts in the hepatic region, resulting in the formation of melanomacrophagic centers. The oocysts were sphere-like, with a diameter of 21 µm. They contained four pyriform sporocysts, 8.7 µm long and 4.9 µm wide, with sporopods in the posterior region.