Revista brasileira de parasitologia veterinaria = Brazilian journal of veterinary parasitology : Orgao Oficial do Colegio Brasileiro de Parasitologia Veterinaria最新文献

The inappropriate use of synthetic acaricides has selected resistant Rhipicephalus microplus populations. The present study evaluated the compatibility of different Metarhizium spp. propagules (conidia, blastospores, and microsclerotia) by incubating them with synthetic acaricides (amitraz, deltamethrin, and a combination of cypermethrin, chlorpyrifos, and citronellal) for 1 h, 5 h, 10 h, and 24 h. Conidia and microsclerotia of the tested isolates were usually more tolerant to synthetic acaricides than blastospores. Our study also analyzed the in vitro effect of deltamethrin associated with fungal propagules for controlling a population of R. microplus females that were not susceptible to this synthetic acaricide. The use of entomopathogenic fungi in association with deltamethrin in this tick population caused a greater tick control than did the use of the fungus or the synthetic acaricide separately.

Alternatives for Rhipicephalus microplus control are needed in the light of its resistance to acaricides. One of the ways to decrease the use of acaricides in a herd is selective control (SC). In the present study, SC was evaluated in a dairy herd consisting of different genetic groups: Holstein, Jersey, crossbreed and Girolando. Ticks were counted in the right anterior third region on around 90 cows, totaling nine evaluations at intervals of 21 days. Commercial pour-on acaricide was applied only when the infestation was greater than or equal to eight ticks larger than 4 mm in the anterior third region. Tick counts were transformed into log10 and analyzed using mixed models. There was significant difference among groups: Holstein had the highest averages of tick numbers, as expected, although 34.3% did not receive tick treatment. In the other groups, SC reduced the use of acaricides by 79.1% for crossbreed, 81.5% for Jersey and 94.9% for Girolando. The criterion used for applying the acaricide successfully kept the tick population under control. The great advantage of SC was savings to the system, without harming the animals, in addition to generate fewer residues in the animals and in the environment.

This study aimed to verify the occurrence of Dioctophyme renale in stray dogs in the city of Pelotas, in the state of Rio Grande do Sul, Brazil. The Laboratório Regional de Diagnóstico of the Universidade Federal de Pelotas received 146 wandering dogs for necropsy, sent by the City Hall of Pelotas from March 2012 to January 2020. Among the necropsied animals, seventeen dogs (11.64%) were diagnosed with dioctophymosis. Among these dogs, 11 were parasitized with one specimen in the right kidney, two dogs presented two specimens in the right kidney, and in other two dogs, the parasites were in the abdominal cavity. In one dog, two parasites were found in the left kidney; in another dog, both kidneys were parasitized, with two parasites in the right kidney and one in the left kidney. The data obtained in this study showed that the occurrence of D. renale in stray dogs in the city of Pelotas is high, and D. renale mainly parasitizes the right kidney.

Ectoparasites of 18 free-living Cuban Ground Doves, Columbina passerina insularis (Columbiformes: Columbidae), captured in the National Zoological Park, Havana, Cuba, were identified. The collected ectoparasites included two species of lice (Phthiraptera: Ischnocera): Columbicola passerinae (77.1%), and Physconelloides eurysema (50%), as well as four species of feather mites (Astigmata: Falculiferidae): Pterophagus lomatus (83.3%), Byersalges talpacoti (50%), Byersalges phyllophorus (72.2%), and Hyperaspidacarus tridentatus (27.7%). Pterophagus lomatus, B. phyllophorus, and H. tridentatus represent new records for Cuba.

Eimeria species have importance to calves because of the economic losses. The aim of this study was to identify the species of Eimeria that affect calves and the risk factors associated with its natural infection. Fecal samples (387) were collected from dairy farms in the southern Agreste of Pernambuco. The feces were evaluated using the Gordon & Whitlock technique and were cultured in 2.5% potassium dichromate for sporulation of oocysts. Odds ratio (OR) were calculated to assess risk factors. Eimeria spp. were detected in 50.65% (196/387) of the samples. Eleven species were identified, being Eimeria bovis (26.64%; 548/2057), Eimeria zuernii (19.69%; 405/2057) and Eimeria ellipsoidalis (14.49%; 298/2057) those more frequent. Small herds (OR = 1.93), calves aged up to six months (OR = 2.12), absence of manure pit (OR = 7.52), fortnightly cleaning (OR = 4.71), collective calf pens (OR = 3.26), manual milking (OR = 2.16) and absence of veterinary care (OR = 2.28) were considered to be risk factors. The data revealed pathogenic species in more than 50% of the farms. Thus, the importance of adopting sanitary measures to reduce the spread of these protozoa in herds should be done, because of economic losses associated with its infection.

A total of 132 flounder specimens (60 Paralichthys isosceles, 36 Paralichthys patagonicus and 36 Xystreurys rasile) were collected off the coast of the state of Rio de Janeiro, Brazil. The fish were measured, necropsied, and had their organs investigated for hemiurid and lecithasterid digenean trematodes and camallanid and cucullanid nematodes. Taxonomic identification of the parasites was based on morphological and morphometric characters and was conducted using bright-field and scanning electron microscopies. The trematodes Lecithochirium monticellii and Aponurus laguncula were found parasitizing P. isosceles, P. patagonicus and X. rasile while the nematodes Procamallanus (Spirocamallanus) halitrophus and Cucullanus bonaerensis were found parasitizing P. isosceles and X. rasile and P. isosceles, P. patagonicus and X. rasile, respectively. Parasite indices of prevalence, mean intensity, mean abundance, and range of infection, as well as infection site, were evaluated for each parasite species. This study allowed to evidence the first occurrence of P. patagonicus by L. monticellii; X. rasile by A. laguncula and P. (S.) halitrophus; and P. isosceles and P. patagonicus by C. bonaerensis in the Western South Atlantic Ocean.

The presence of antibodies anti-Toxoplasma gondii and Neospora caninum have been described in dogs from virtually all Brazilian states, however in the state of Amazonas, there are few studies on these coccidia. In this study the occurrence of antibodies against T. gondii and N. caninum and risk factors were determined in domiciliated dogs of Manaus, AM. Blood samples were collected from 154 dogs and, during the harvest, a questionnaire was applied with questions related to the animals. The samples were analyzed, for the presence of anti-T. gondii and N. caninum antibodies, by indirect fluorescence antibody test, with cutoff of 16 and 50, respectively. Associations between the variables studied and the presence of antibodies were made by chi-square test, fisher's exact test or G test (p<0.05). Of the 154 samples, 19 (12.3% 95% CI = 7.1% - 17.5%) were reagents to T. gondii, and association (p <0.05) was observed between the presence of antibodies and contact with other dogs. The occurrence of dogs reactive to N. caninum was 1.9% (95% CI = 0.4% - 5.6%) with 3 of the 154 dogs positives, and no association (p>0.05) was observed between the presence of N. caninum antibodies, and the variables studied.

The aim of this study was to validate a one-tube nested real-time PCR assay followed by genetic sequencing to detect and identify Cryptosporidium species and genotypes in birds. A total of 443 genomic DNA extracted from avian fecal samples were analyzed by one-tube nested real-time PCR and conventional nested PCR. By one-tube nested real-time PCR, 90/443 (20.3%) samples were positive for Cryptosporidium spp. In contrast, 36/443 (8.1%) samples were positive for Cryptosporidium spp. by conventional nested PCR. The analytical sensitivity test showed that one-tube nested real-time PCR detects approximately 0.5 oocyst (2 sporozoites) per reaction. An evaluation of analytical specificity did not reveal amplification of microorganisms that commonly present nonspecific amplification with primers used for the diagnosis of Cryptosporidium spp. The repeatability analysis showed the same result in 27 out of 30 samples (90%). As for the reproducibility of one-tube nested real-time PCR, 24 of the 30 samples examined (80%) showed the same result. All the 90 samples amplified by one-tube real-time nested PCR were successfully sequenced, leading to the identification of C. baileyi, C. galli, C. meleagridis, C. proventriculi, and Cryptosporidium avian genotype I. Genetic sequencing of conventional nested PCR amplicons was successful in 10/36 (27.8%) of positive samples.

This study aimed to evaluate foraging distance (FD) from the dung, parasitological and physiological factors in 18 Crioula Lanada lambs naturally infected by nematodes with three infection levels (IL) in a Voisin Grazing System. In the pre-experimental phase animal feces collection, deworming, observer training, animal adaptation and dung demarcation were carried out; in the experimental phase, grazing distance, feces, pasture and blood sampling. An initial exploratory analysis was carried out (Kruskal-Wallis test). Fixed predictors were selected with a cumulative logit regression model; an ordinal logistic regression mixed model identified influencing factors of ordinal responses for (i) FD, (ii) infective larvae quantity (L3). Animals approached the dung when the radiation or temperature were more intense (P < 0.05). Paddock entry/exit, IgG and L3 influenced FD over time (P < 0.05). L3, in turn, was influenced by IL, FEC and corpuscular volume (CV). In the High IL group, FD varied between 60-100 cm. Greater L3 and FEC were found in the High and Low IL from the 4th week (P < 0.05). Naturally infected Crioula Lanada lambs increased the distance from the dung, which was not related to IL but to the dynamics of solar radiation and parasitological and immunological factors.