Toxoplasmose em suínos de criações de subsistência no estado de Pernambuco, Brasil : soroprevalência, isolamento e genotipagem de Toxoplasma gondii

Abstract

Toxoplasma gondii is an obligate intracellular coccidian protozoan that causes the toxoplasmosis, an important zoonosis. The study of the prevalence of this parasite in pigs have great importance since pork is one of the main sources of infection for humans when consumed raw or undercooked. This study aimed to determine the prevalence of antibodies, isolate and genetically characterize the Toxoplasma gondii in subsistence creations of pigs in the State of Pernambuco, Brazil. In the first study it was evaluated 224 blood samples and tissues from pigs slaughtered in municipal slaughterhouses for the presence of anti-Toxoplasma gondii antibodies by Indirect Immunofluorescence Assay (IFA). There was a significant relationship regarding the age of the animals and seropositivity (p <0.001). The positive animals had their tissues analyzed by bioassay techniques in mice, Histopathology, Immunohistochemistry (IHC) and Polymerase Chain Reaction (PCR). Of animals sampled, 38.0% (85/224) were positive in the IFA with titles ranging from 64 to 1024. In the histopathology, it was not observed injuries associated to toxoplasmosis in the evaluated tissues and in the IHC it was not obtained positive immunostaining. The PCR of pig tissues showed 14.1% (12/85) positive samples and in the mouse bioassay, 28.0% (5/18) of the samples were positive. The second study was realized with the purpose of discovering the genotypes of T. gondii in the region. It was realized a screening of positive animals in the serological tests, then, the tissues of positive animals were used for bioassay. Fifteen pools of tissues were used, of which, was obtained one isolate. The isolate obtained was characterized by RFLP -PCR, using 11 genetic markers (SAG1, SAG2, altSAG2, SAG3, BTUB, GRA6, c228, c292, L358, PK1 e APICO). It was used the RH, ME49 and VEG strains of T. gondii, that belong to types I, II and III respectively as standard in genetic characterization of isolated swines. After this genetic analysis, it was identified genotype #65 (ToxoDB), considered an atypical strain and also the first record of this genotype in pigs worldwide. The results of this study allow to conclude that Toxoplasma gondii is installed in pig herds in the state of Pernambuco and strategic and integrated measures should be taken around the prophylaxis of this disease, to prevent and control the infections in pigs and humans in the studied region.