Seroprevalence and genetic characterization of Toxoplasma gondii in domestic pigs intended for human consumption in Cuba

Domestic pigs are considered as one of the main intermediate hosts in the zoonotic transmission of Toxoplasma gondii in many countries. Serological and molecular studies are warranted to better understand the epidemiology and transmission patterns of this parasite worldwide. To date, seroepidemiological information on T. gondii in domestic pigs in Cuba is very scarce and there are no reports of T. gondii genotypes circulating in this country. Here, we aimed to estimate the seroprevalence of T. gondii and provide genetic characterization of the strains circulating in slaughtered pigs intended for human consumption in Central Cuba. Seroprevalence was determined in 450 serum samples from slaughtered pigs in Villa Clara province using ELISA. Anti-Toxoplasma gondii IgG antibodies were detected in 100 animals (22.2%, 95% CI: 18.5-26.2). Conventional PCR of the 529-bp marker of T. gondii was performed in hearts and diaphragm tissues of all ELISA-seropositive pigs. Toxoplasma gondii DNA was detected in four animals. Further genetic characterization of the positive DNA samples was performed by multilocus PCR-RFLP and PCR-sequencing typing tools. Molecular analysis revealed four different genetic profiles that were combinations of type I, II, III and u-1 alleles, suggesting the circulation of non-clonal genotypes of T. gondii in domestic pigs in Cuba. Our results indicate that T. gondii is widely distributed in slaughtered pigs in this country, which might have important implications for public health. To the best of our knowledge, this is the first report on genetic characterization of T. gondii in Cuba. Although preliminary, the results suggest a high genetic diversity of T. gondii in the study region. Further studies based on parasite isolation are needed to definitively identify the genotypes circulating and characterize the virulence of strains detected in pigs in Cuba, and to assess the risk of zoonotic transmission from pork products in this country.