Alguns aspectos da epidemiologia de Isospora suis Biester & Meurray, 1934 em granjas de suinos da região leste do Estado de São Paulo

Orientador: Urara KawazoeDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de BiologiaResumo: Atualmente Isospora suis vem sendo considerada como importante enteroparasita para leitões, causando severos danos à suinocultura industrial. O sinal clínico mais evidente é a diarréia pastosa amarelada, a qual não responde a tratamento com antibióticos. A doença representa 15 a 20% dos casos de diarréias de leitões lactentes enviados para diagnóstico nos laboratórios dos Estados Unidos e Canadá. No Brasil existem relatos de surtos da doença em Minas Gerais, Santa Catarina e Rio Grande do Sul. Os objetivos deste trabalho foram de verificar a prevalência de I.suis na Região Leste do Estado de São Paulo e observar a manifestação clínica da doença. Foram estudadas 33 granjas com e sem histórico de diarréia compativel com a isosporose, pertencentes a 20 Municípios. Foram colhidas 177 amostras de fezes em leitões entre 10 a 50 dias de idade, lactentes e desmamados. A presença de oocistos foi relacionada com o tipo de instalação e manejo da maternidade e creche. A análise estatistica dos dados obtidos foi realizada através do teste de Qui-quadrado. O presente trabalho mostrou _e existe relação entre granja com histórico e presença de oocistos e a faixa etária mais acometida era de leitões entre 10 a 19 dias de idade. Em granjas sem histórico a freqüência de oocistos era menor e ocorria igualmente entre leitões de 10 a 50 dias de idade. Nao foi observado diferença entre a eliminação de oocistos em leitões lactentes e desmamados. Em maternidades suspensas a presença de oocistos foi significativamen te menor do que em maternidades "no chão e sujas", onde o acesso às fezes era maior. Em 7 amostras foram observados oocistos cuja parede apresentava-se delgada e retraida, semelhante a Sarcocvstis _. Quatro dessas amostras foram purificadas e inoculadas experimentalmente em 4 leitões para a con firmação da espécie. O ciclo biológico e os sinais clínicos confirmaram que os oocistos inoculados eram de I. suis. Entretanto novos estudos são necessários para esclarecer se os oocistos de parede delgada ocorrem em alguma fase particular do ciclo da Isospora suis ou se pertencem a cepas especificasAbstract: Presently Isospora suis is considered as important enteropathogen of swine and cause a sisnificant problem in the swine industry. The disease is associated with scours in piglets 5-10 days of age which are generally nonresponsive to most antibacterial drugs. Isosporosis accounts for about 15 20% of alI cases of neonatal swine diarrhea submitted to United States and Canada diagnosic laboratories. They are in Brasil a report of isosporosis outbreak in Minas Gerais, Santa Catarina e Rio grande do Sul. The objective of this study was to verify the I.suis prevalence in East Sao Paulo Region and observe the clinical signs. It was performed 33 swine farms from 20 municipalites of Sao Paulo State, by collecting 177 fecal samples from nursing and weanling piglets. History of neonatal isosporosis as well type of farrowins aNd nursery houses of thouse farms were correlated to presence of I.suis oocysts. Six fecal samples were taken from each farm (2 from statistical analysis. Oocists were more freguent in farms with history of neonatal isosporosis than in those without and there history to 19 were no relation to fecal consistency. In with farms of isosporosis fecal samples from piglets between 10 weanling pigs. Their presence showed no difference between nursling and day-old had higher frequency of oocysts than in other piga. Oocyata were more frequent in fecal samples collected from dirty solid floors than from self-cleaning flo ors houses in the farrowing houses. Type and management of nursery were not associated with the presence of oocysts in wealing pigs. Of 177 Athin wall type I.suis oocysts was detected in seven wall similar to that from genus Sarcocvstis. Four of this type fecal samples. This type of oocysts had aretracted of oocysts contamination signs, the oocysts. Type could was inoculated in 4 five-day-old of pigs free for species confirmation. The clinical lesions and the life cycle confirmed that it was a I.suis Additional studies are needed to determine that tM of oocysts could appear in specific strains of I.suis or be a characteristic of certain strains wich occurs in the later stages of their developmentMestradoParasitologiaMestre em Ciências Biológica

Experimental Infection of Swine by Isospora suis Biester 1934 for Species Confirmation

A survey of Isospora suis performed in 177 faecal samples from 30 swine farms detected thin wall type I. suis oocysts in seven samples. This type of oocyst measuring 23.9 by 20.7 mm had a retracted thin wall similar to that of the genus Sarcocystis. This type of oocysts, isolated from four different faecal samples, was inoculated in four-five-days-old piglets free of contamination in order to verify the life cycle and pathogenicity of the species. The pigs were kept in individual metal cages and fed with cow milk. Daily faecal collections and examinations were performed until the 21st day after infection. MacMaster and Sheather' s methods were used for oocyst counting and identification. Infected piglets produced yellowish-pasty diarrhoea with slight dehydration. The prepatent and patent periods were respectively from 6 to 9 and 3 to 10 days after infection. Oocyst elimination was interrupted on the 10th and 11th days after infection with biphasic cycles. Thin and thick wall oocysts were detected in the same faecal samples. Thin walls were not observed in unsporulated oocysts. The observations suggest that this type of oocysts could appear in specific strains which occur in the later stages of their development. These oocysts seem to be responsible for clinical and pathogenic signs of neonatal isosporosis in pigs