Resistência contra ectoparasitas em bovinos da raça Crioula Lageana e meio-sangue Angus avaliada em condições naturais / Resistence against ectoparasites in CriouloLageano and crossbred Angus cattle in southern Brazil under natural conditions

Este trabalho foi desenvolvido com o objetivo de avaliar a resistência aos ectoparasitas em bovinos jovens da raça Crioula Lageana e meio-sangue Angus em condições naturais. Foram utilizados 10 machos castrados em cada grupo, recém desmamados (6-8 meses) e mantidos sob as mesmas condições de manejo, em pastagens cultivadas de inverno e verão, no município de Monte Castelo - SC, sofrendo infestação natural por ectoparasitas. A cada 28 dias, fêmeas de carrapatos (Rhipicephalus (Boophilus) microplus) com tamanho acima de 4 mm foram quantificadas nos dois lados do corpo de cada animal, bem como os nódulos com larvas de Dermatobia hominis. A espessura da capa do pelame foi também avaliada a cada coleta e os animais foram classificados quanto à coloração do pelame. Os animais da raça Crioula Lageana foram mais resistentes às infestações por D. hominis e R. microplus. Não houve diferença entre a disposição de carrapatos e bernes conforme os lados direito e esquerdo dos animais. Os animais de pelagem escura albergaram a maior porcentagem de ectoparasitas nos grupos avaliados.

This study was carried out to evaluate the breed resistance against ectoparasites infestations in Crioula Lageana and crossbred Angus male calves under natural condition. Ten weaned and neutered male calves (6-8 months) of each group were kept together in winter and summer pastures in Monte Castelo, Santa Catarina State. Every 28 days, female ticks (Rhipicephalus (Boophilus) microplus) more than 4 mm long were counted on the right and left side of the body of each animal, as well as the D. hominis nodules. Coat thickness also was measured at each sampling and all animals were classified according coat color. Crioula Lageana group was less infested by D. hominis than crossbred Angus in five times and by ticks in the infestation peak (P<0.05). There were no differences in the distribution of the ticks and grubs between animal body sides. Dark-haired animal in both groups were the most susceptible.

Resistance against gastrointestinal nematodes in Crioulo Lageano and crossbred Angus cattle in southern Brazil.

Gastrointestinal nematode (GIN) infection is a major cause of production losses in cattle. This study was carried out to evaluate the natural resistance against nematode infection in Crioulo Lageano and crossbred Angus male calves. Crioulo Lageano is a local cattle breed in the state of Santa Catarina, in southern Brazil. Ten weaned calves of each breed were grazed together on pasture and naturally infected with nematodes between July 2009 and December 2010. Once every 28 days, we collected fecal and blood samples for parasitological and immunological tests, as well as recording body weights. After 19 samplings, all animals were slaughtered for quantification and identification of GINs. We found that the animals had been infected with the following nematode species, in decreasing order by the mean number of specimens: Trichostrongylus axei, Cooperia punctata, Ostertagia ostertagi, Haemonchus placei, Oesophagostomum radiatum, and Trichuris spp. There were no significant differences between the Crioulo Lageano and crossbred Angus groups in terms of worm burden or nematode fecal egg count, nor in terms of the mean levels of immunoglobulin (G and A) against C. punctata and H. placei antigens, except in IgA mean level in abomasal mucus against H. placei adult worms that was significantly higher in crossbred Angus cattle (p<0.05). At the end of the study, the crossbred Angus cattle were heavier than were the Crioulo Lageano cattle (mean live weight, 507.35 and 390.3 kg, respectively). Comparative parasitological and immunological evaluation revealed no difference between two breeds in terms of their natural resistance against GINs.

Morphologic organization of pulmonary granulomas in mice infected with Paracoccidioides brasiliensis.

A morphologic study of the lungs was carried out in Swiss mice infected with yeast isolated from Paracoccidioides brasiliensis (Pb18). The lung was processed 1, 2, 4, and 8 weeks after inoculation for histologic staining with hematoxylin and eosin (H&E), methenamine silver nitrate (Gomori-Grocott), and picrosirius to qualitative and quantitative analyses of the granulomas and the presence of fungal lesions. The numbers of CFUs/g counted in the lungs were 189.8 +/- 20.64, 353.6 +/- 46.21, 547.2 +/- 108.1, and 295.2 +/- 89.17 in the first, second, fourth, and eighth weeks, respectively. One week after infection, inflammatory cells and reticular and collagens fibers, the latest typical of fibrosis, were detected. After 2 and 4 weeks, a progressive intensification of the infection and fibrosis was observed, but in week 8 a more organized granuloma was evident, with macrophages, epithelioid cells, and yeasts in the central portion, and intense peripheral basophilia. Pycnotic structures typical of apoptotic bodies were observed in weeks 1 and 8. The different histologic staining used acted as a fundamental tool for the study of the morphologic organization of granuloma formation.

Proposta para teste carrapaticida por imersão de larvas de Rhipicephalus (Boophilus) microplus: avaliação em cipermetrina e amitraz / Proposal of an acaricide laboratory test larvae immersion of Rhipicephalus (Boophilus) microplus: evaluation with cypermethrin and amitraz

The aim of this work was to develop a technique of acaricides evaluation by immersion of larvae. Larvae were obtained from 30 engorged females of Riphicephalus (Boophilus) microplus were collected in a ranch in Lages, Santa Catarina state, Brazil. Larvae were obtained from 10mg of eggs placed into 5ml disposable syringes, previously prepared and kept under controlled conditions of laboratory, and collected between the third and the twelfth day of oviposition. Seven to ten days old larvae were submitted to the acaricide laboratory test, in ten replications, by their immersion in eight dilutions of commercial acaricides (amitraz or cypermethrin), for 30 seconds; for each replication and commercial product, a control group was immersed in distilled water. Results were evaluated 24 hours after each treatment by counting the number of live and dead larvae. The mean LD50 values and standard error of the mean for cypermethrin and amitraz were 2.99 ± 0.36 and 17.22 ± 4.20 ppm, respectively, for a confidence interval of 95 percent. The proposed acaricide laboratory test procedures by larvae immersion offered promising results for the evaluation of acaricides.

Objetivou-se desenvolver uma técnica de avaliação de carrapaticidas por imersão de larvas de Riphicephalus (Boophilus) microplus. As larvas foram obtidas a partir de ovos de 30 teleóginas coletadas em bovinos de uma propriedade rural do município de Lages, SC, Brasil, os quais foram acondicionados em alíquotas de 10mg por seringa descartável de 5ml, previamente preparadas e mantidas em câmara climatizada até a eclosão. Larvas com sete a dez dias de idade foram submetidas à imersão por 30 segundos em oito diluições de produtos carrapaticidas comerciais à base de amitraz e de cipermetrina, cada uma com dez repetições, sendo mantido um grupo controle para cada repetição e produto, o qual foi imerso em água destilada. A leitura foi realizada 24 horas após o tratamento com a contagem de larvas vivas e mortas. A média de DL50 para cipermetrina foi de 2,99ppm e o erro padrão de 0,36 e para o amitraz foi de 17,22ppm e o erro padrão de 4,20, com intervalo de confiança (IC) 95 por cento.

[Amblyomma tigrinum in the Municipality of Lages, SC, and biology observations under laboratory conditions]. / Amblyomma tigrinum no Município de Lages, SC e observações da biologia em condições de laboratório.

To study the biological features of Amblyomma tigrinum, samples of engorged females collected from dogs in the city of Lages, SC, Brazil, were maintained in Petri dishes into an incubator at 27+/-1 degrees C and 80+/-10% RH, for egg laying. For the development of the subsequent experimental phases, artificial infestations were performed in rabbits using the technique of the cotton bag glued to the ear's base. The mean period of hatch, feeding and larval molt were 11.67, 5.93 and 10.96 days, respectively, whereas the mean period of feeding and nymph's molt were 12.40 and 16.27 days, respectively. Only one engorged female was obtained, with detachment observed on the 22(nd) day. The longevity periods for larvae, nymphs and adults were 75, 96 and 150 days respectively.

Amblyomma tigrinum no Município de Lages, SC e observações da biologia em condições de laboratório / Amblyomma tigrinum in the Municipality of Lages, SC and biology observations under laboratory conditions

Com objetivo de observar os parâmetros biológicos de Amblyomma tigrinum, fêmeas ingurgitadas, coletadas de cães da cidade de Lages-SC, foram acondicionadas em placas de Petri, mantidas em câmara climatizada tipo BOD regulada à temperatura de 27 + 1º C, 80 + 10 por cento UR e escotofase para realização da postura. Para o desenvolvimento das fases sucessivas do experimento, foram realizadas infestações em coelhos, por meio da técnica do saco de pano aderido à base das orelhas. Os períodos médios de eclosão, de ingurgitamento e de ecdise larval foram de 11,67; 5,93 e 10,96 dias, respectivamente. Os períodos médios de ingurgitamento e de ecdise ninfal foram de 12,40 e 16,27 dias respectivamente. Foi obtido o ingurgitamento de uma fêmea, com desprendimento no 22º dia. A longevidade foi de 75, 96 e 150 dias, para larvas, ninfas e adultos respectivamente.

To study the biological features of Amblyomma tigrinum, samples of engorged females collected from dogs in the city of Lages, SC, Brazil, were maintained in Petri dishes into an incubator at 27±1ºC and 80±10 percent RH, for egg laying. For the development of the subsequent experimental phases, artificial infestations were performed in rabbits using the technique of the cotton bag glued to the ear's base. The mean period of hatch, feeding and larval molt were 11.67, 5.93 and 10.96 days, respectively, whereas the mean period of feeding and nymph's molt were 12.40 and 16.27 days, respectively. Only one engorged female was obtained, with detachment observed on the 22nd day. The longevity periods for larvae, nymphs and adults were 75, 96 and 150 days respectively.

[Proposal of an acaricide laboratory test larvae immersion of Rhipicephalus (Boophilus) microplus: evaluation with cypermethrin and amitraz]. / Proposta para teste carrapaticida por imersão de larvas de Rhipicephalus (Boophilus) microplus: avaliação em cipermetrina e amitraz.

The aim of this work was to develop a technique of acaricides evaluation by immersion of larvae. Larvae were obtained from 30 engorged females of Riphicephalus (Boophilus) microplus were collected in a ranch in Lages, Santa Catarina state, Brazil. Larvae were obtained from 10mg of eggs placed into 5ml disposable syringes, previously prepared and kept under controlled conditions of laboratory, and collected between the third and the twelfth day of oviposition. Seven to ten days old larvae were submitted to the acaricide laboratory test, in ten replications, by their immersion in eight dilutions of commercial acaricides (amitraz or cypermethrin), for 30 seconds; for each replication and commercial product, a control group was immersed in distilled water. Results were evaluated 24 hours after each treatment by counting the number of live and dead larvae. The mean LD50 values and standard error of the mean for cypermethrin and amitraz were 2.99 +/- 0.36 and 17.22 +/- 4.20 ppm, respectively, for a confidence interval of 95%. The proposed acaricide laboratory test procedures by larvae immersion offered promising results for the evaluation of acaricides.