Toxoplasma gondii molecular and immunological identification and risk factors associated with infection in chicken slaughtered at triângulo Mineiro region, Minas Gerais, Brazil

Abstract

This study aimed to determine the occurrence of anti-Toxoplasma gondii antibodies in the serum of slaughtered chickens in the region of Triângulo Mineiro, Minas Gerais, Brazil, to detect the parasite in tissues (heart and brain) of serologically positive chickens, based on molecular analysis, and to investigate risk variables associated with the infection. Sera from 417 chickens raised in extensive, semi-intensive, and intensive production systems were tested by an indirect immunofluorescent antibody test (IFAT) and indirect hemagglutination antibody test (IHA). Polymerase chain reaction (PCR) was performed to detect T. gondii DNA in brain and heart tissues. Antibody anti-T. gondii were found in 37.65% (157/417) of chickens by IFAT, and in 75.06% (313/417) by IHA. The Kappa index showed a weak concordance between the techniques (0.087). Association was observed between seropositivity and the variables, age (p < 0.0001), type of feeding (p < 0.0001) and collective raising with other animal’s species (p < 0.0001). Association, based on IFAT, was not observed between seropositivity and the variables, sex (p = 0.0526), presence of cats (p > 0.9999), and presence of rats (p > 0.9999). Presence of parasite DNA was detected in brain samples from two chickens, which were raised in intensive and semi-intensive production systems. The results suggest the meat of these slaughtered animals may serve as a transmission source of this protozoan to humans.