Revista Brasileira De Parasitologia Veterinaria最新文献

Bovine parasitic otitis poses challenges in diagnosis, treatment and involves various agents, such as bacteria, fungi, mites, and nematodes. This study focused on the nematodes and bacteria isolated from the auditory canals of dairy cattle. A total of twenty samples were collected from dairy cattle in two states of Brazil. The results showed that Metarhabditis freitasi and M. costai nematodes were identified in 75% of samples. Bacterial species from the ear, identified via mass spectrometry, revealed that different strains were present in 65% of the cattle. Mycoplasma spp. were identified in 45% of samples through molecular techniques. Gram-negative bacteria and Mycoplasma spp. were exclusively found in nematode-infected cattle. Furthermore, the bacteria exhibited resistance to multiple antimicrobial classes, and demonstrating multiresistance. Electron microscopy revealed biofilm aggregates on the cuticle of Metarhabditis spp., suggesting a potential role of these nematodes in bacterial migration and interaction with nervous tissue. Thirteen bacterial strains demonstrated biofilm formation ability, indicating their potential pathogenic role. This research highlights the persistent and complex nature of parasitic otitis, emphasizing the significant role of nematode-bacteria associations in its pathogenicity. The presence of resistant strains and biofilm formation underscores the challenges in managing the diagnosis and treatment of bovine parasitic otitis.

This paper describes a novel in vivo study of Cymbopogon citratus (lemon grass) to assess its anthelmintic activity. To this end, C57BL/6 mice were separated into three groups: G1: uninfected; G2: negative control infected with Heligmosomoides polygyrus bakeri and administered with 3% dimethyl sulfoxide (DMSO); and G3: infected with H. polygyrus bakeri and treated with C. citratus aqueous extract (50mg/kg). The extract and H. polygyrus bakeri were administered via gavage and the anatomo-histopathological evaluation of the animals took place after necropsy and organ removal. In addition, the number of eggs per gram of feces (epg) and of adult parasites in the small intestine of each animal, as well as blood cell counts, were assessed. The in vivo assay revealed a reduction in the epg (54%), number of adult nematodes (89%), number of eosinophils, and intestinal lesions in mice treated with C. citratus. These results suggest that the crude aqueous extract of C. citratus at the dose evaluated here has anthelmintic and possibly anti-inflammatory properties, given its effectiveness against gastrointestinal H. polygyrus bakeri nematodes and the recovery of damaged tissues. Therefore, this plant shows potential to control gastrointestinal nematodes.

Canine monocytic ehrlichiosis (CME) is an infectious disease that causes hematological changes in dogs. This study investigated the correlations between hematological and hemorheological parameters, serum proteins, and triglycerides in dogs with CME. Fifty-nine blood and/or bone marrow samples were collected from dogs with or without clinical signs of CME. Blood samples preserved with EDTA were subjected to rheological analysis to investigate blood viscosity. Fourteen dogs with Ehrlichia canis infection (CME group) and 20 without clinical signs and E. canis infection (CG) were selected by qPCR based on Ecaj_0503 gene. The blood viscosity of the infected dogs (CMEG) was lower than that of the control group (CG). The mean values and standard error of erythrocytes (CG: 6.71 ± 0.20; CMEG: 4.82 ± 0.23), platelets (CG: 235.6 ± 15.67; CMEG: 151.07 ± 16.51), and albumin (CG: 3.04 ± 0.15; CMEG: 2.65 ± 0.12) in the infected dogs were lower (p<0.005) than those in the control group. The decrease in erythrocytes influenced the decrease in blood viscosity. Total protein, albumin and triglycerides levels correlated with blood viscosity in infected dogs. Overall, this study shows that dogs with CME have decreased blood viscosity primarily due to anemia and interactions with negative acute-phase proteins.

A total of 384 animals (sheep, goat, cattle, and buffalo) were examined for the presence of hydatid cysts only in the lungs. The lung tissue samples associated with the hydatid cyst were collected immediately after slaughter, followed by fixation in 10% formalin. The fixed tissue was subjected to paraffin embedding technique. Tissue sections of 5 microns were cut by microtome and stained using Harri's Haematoxilin and Eosin method. Overall, 13.80% of ruminants were found positive for lung infections with hydatid cyst. Only the sex of ruminants showed significant (P < 0.05) association with the infection of hydatid cyst in lungs. All other variables, such as species of ruminants, age, and months showed non-significant (P > 0.05) association. Pulmonary sections taken from infected animals revealed laminated membranes encased in a region with significant (P < 0.05) cellular infiltration (53.4 ± 7.9 µm2), primarily composed of lymphocytes, plasma cells, macrophages, and occasionally neutrophils, and eosinophils. In addition, significant (P < 0.05) epithelial disruption in the bronchioles (0.94 ± 0.05 µm2) and alveolar septa were also noticed in sections. These histopathological findings lead to the conclusion that pathological changes occur in the tissues surrounding the cyst as well as in areas more distant from the cyst.

In Brazil, spotted fever (SF) is caused by two species of Rickettsia, both of which are transmitted by Amblyomma ticks: Rickettsia rickettsii, which results in severe and often fatal cases, and Rickettsia parkeri, which causes a mild illness. This study focused on R. parkeri in Amblyomma ovale ticks from the Maciço de Baturité region, Ceará, Northeast Brazil, an area endemic for SF with mild symptoms. We examined 60 domestic dogs with access to the forest for ticks and Rickettsia seroprevalence. A landscape analysis was conducted in all forest patches within 2-10 km from the main forest edge. In total, 125 A. ovale ticks were collected from 30 dogs (50%). DNA from 65 ticks was tested using genus-specific Rickettsia primers. Three (4.6%) tick specimens tested positive for R. parkeri while the Rickettsia seroprevalence among the dogs was 55% (33/60). A probable occurrence of Rickettsia transmission was observed in the fragmented Atlantic rainforest, which has 1,019 ha of preserved land and 50.6 km of perimeter border. The land's characteristics allow for semi-domiciled dogs to access forest fragments, where A. ovale ticks are commonly present. Infected ticks may parasitize the dogs, which then transport the ticks into homes, potentially transmitting SF-causing bacteria to humans.

A new parasite of the Class Myxozoa is described in the gallbladder of the ornamental angelfish Pterophyllum scalare, in two municipalities in the state of Amapá, Brazil, based on morphological, morphometric and phylogenetic descriptions. From October 2022 to August 2024 fifty-five angelfish specimens were sampled in Macapá (n=10) and Tartarugalzinho (n=45). Slightly arched mixospores were observed by light microscopy and had characteristics consistent with those of the genus Ceratomyxa. These obtained an average length of 1.6 ± 0.2 µm and 11.5 ± 1.1 µm in thickness. The polar capsules were subspherical and 0.7 ± 0.1 µm long and 0.6 ± 0.1 µm wide, with 3 to 4 turns of the polar filament. Phylogenetic analysis showed that the new species is grouped in the family Ceratomyxidae, in addition to being positioned in the same subclade of freshwater ceratomyxids from the Brazilian Amazon, demonstrating that this species shares a common ancestor with its close relatives, based on geographic affinity. Ceratomyxa tavariensis n. sp. is the first species of the class Myxozoa described infecting angelfish in Brazil, and the thirteenth species of Ceratomyxa described in the country.

Little is known about parasites in wild mammals kept as pets. For this study, fecal and skin/fur samples and ectoparasites from 55 wild and pet mammals attended at a veterinary clinic were evaluated. Opossums (Didelphis albiventris and Didelphis aurita) were parasitized by helminths (Aspidodera sp., Cruzia tentaculata, Trichuris sp., Turgida turgida and Acanthocephala gen. sp.), screw-worm fly larvae (Cochliomyia hominivorax), ticks (Amblyomma dubitatum and Amblyomma sculptum) and fleas (Ctenocephalides felis). Hedgehogs (Atelerix albiventris) were parasitized by mites (Caparinia tripilis), capybaras (Hydrochoerus hydrochaeris) by ticks (A. dubitatum and A. sculptum), a ferret (Mustela putorius furo) by fleas (C. felis), an orange-spined hairy dwarf porcupine (Sphiggurus villosus) by screw-worm fly larvae (C. hominivorax) and another for ticks (Amblyomma longirostre). Overall, mites were found only in pet animals and helminths were found only in wild animals. Infestation by Caparinia tripilis was only found in animals with concomitant illness or stress. Cruzia tentaculata actively exited its opossum host by passing through the animal's anus as its clinical condition worsened.

Gallery forests harbor mammals and sand flies that may be involved in the transmission of Leishmania spp. parasites. Characterizing the enzootic cycles of Leishmania spp. is essential for understanding its transmission dynamics. We analyzed the presence of Leishmania spp. in mammals and sand flies in gallery forests during the dry season in the Cerrado. Four gallery forests were investigated in May and September 2014. Our capture effort included 1,280 HP trap-nights, 16 Shannon trap-nights for sand flies, and 5,120 trap-nights for mammals. After identifying the mammalian and sand fly species, SSU rRNA and ITS-1 polymerase chain reaction (PCR) were used to detect Leishmania spp. A total of 1,209 sand flies belonging to 13 species were captured, mainly Bichromomyia flaviscutellata. Leishmania spp. DNA was not detected in the analyzed sand fly females. PCR analysis of 153 mammals revealed Leishmania spp. in 20 samples (13%) in May (early dry season), when the infection rate was 31% in one gallery forest. The host species were Rhipidomys macrurus, Gracilinanus agilis, and Didelphis albiventris. We observed a low frequency of mammals infected with Leishmania spp., which was not detected in sand flies. Our results indicate that Leishmania spp. infection is higher in mammals during the early dry season in Cerrado gallery forests.

Canine leishmaniasis is a parasitic disease whose agents are transmitted through the bites of infected phlebotomine sand flies. This disease is endemic in tropical and subtropical regions, including Brazil. However, information on its prevalence in dogs in some Brazilian states remains limited. This study aimed to assess the seroprevalence of canine leishmaniasis in Rio Branco, Brazil. Blood samples were collected from 375 dogs aged > 6 months. Two distinct serological methods, dual path platform test (DPP) and enzyme linked immunosorbent assay (ELISA), were used to investigate the occurrence of anti-Leishmania spp. antibodies. The results showed a seroprevalence of 38.1%, indicating that the disease occurred in this region. Blood samples considered positive in at least one of the serological methods were subjected to conventional polymerase chain reaction (PCR), which confirmed the presence of infection in 28.3% (106/375) of the total samples. This is the first study to provide detailed information on the seroprevalence of canine leishmaniasis in dogs in Rio Branco, highlighting the importance of disease surveillance and control. Effective actions, such as education campaigns on sand fly prevention and control measures, are necessary to reduce the occurrence of canine and human leishmaniasis in cities.

Some fish parasites can cause a variety of symptoms in humans, including allergies. This was a cross-sectional study based on interviews, serum analysis by ELISA for anti-Pterobothrium heteracanthum IgG and a statistical evaluation. Four individuals were seroreactive (6.25%), with no association with fish handling (p = 1.000) or with ingestion more than twice a week (p = 0.232). There was a significant association (p = 0.032) between reactivity and the absence of allergy symptoms. Seroreactivity against P. heteracanthum in humans was detected, but was not associated with the amount of fish ingested, handled, or with allergic complaints.