Isolamento e identificação de Toxoplasma gondii em galinhas (Gallus gallus domesticus) comercializadas em mercados populares no estado de Pernambuco, Brasil

Abstract

Toxoplasma gondii is an obligatory intracellular parasite with worldwide distribution and capable of parasitizing several homeothermic species, and which is of great importance due to its zoonotic potential. The aim of this study was to isolate and identify T. gondii from tissues of domestic chickens (Gallus gallus domesticus) raised extensively and intended for human consumption. Blood and tissue samples were collected from 25 chickens destined for slaughter. Initially, the Indirect Immunofluorescence Assay (IFAT) technique was used as screening to detect antibodies anti-T. gondii. The positive animals at the cutoff point of 16 had their tissues (brain and heart) subjected to the Bioassay in a murine model, using Swiss-Webster mice. The inoculated mice were evaluated for a 45 days period, and on the thirtieth day post-inoculation, a blood sample was collected from each inoculated mouse to detect antibodies anti-T. gondii by IFAT. Animals were euthanized on day 45 p.i. and those positive at the cutoff point of 1:16 had their brains evaluated for T. gondii cysts and subsequently inoculated into an in vitro culture of MA-104 (ATCC® CRL-2378.1) cells. Aliquots of mouse tissue and cell culture were subjected to Polymerase Chain Reaction (PCR) for confirmation through detection of the ITS-1 gene. A frequency of 68.00% (17/25) of anti-T. gondii in the evaluated chickens, which resulted in a seroconversion of 64.70% (22/34) in the inoculated mice. Seven T. gondii isolates were obtained with genetic characterization of three isolates revealing two genotypes (ToxoDB#36 and #114). From the results obtained, the presence and viability of T. gondii cysts in chickens intended for human consumption is reported. This occurrence reflects the status of environmental contamination, providing data regarding the circulation of a zoonotic agent of severe importance for public health. The presence of atypical genotypes can be attributed to the genetic diversity recorded in this region. We highlight the occurrence of the ToxoDB#36 genotype in chickens in the Pernambuco state.