Molecular Detection and Prevalence of Toxoplasma gondii in Ready-to-eat Vegetables and Oysters in Central Luzon, Philippines

Toxoplasmosis, a parasitic infection caused by T. gondii, may be considered as a neglected disease in the Philippines. Consumption of raw or undercooked cyst-containing meat and accidental ingestion of oocysts excreted in the environment are two of the main routes in acquiring the infection. In the Philippines, there is no comprehensive or updated information on the prevalence of T. gondii among human populations and as a food-borne pathogen. We detected T. gondii DNA in ready-to-eat (RTE) vegetables and oysters sold in markets in Central Luzon, Philippines using molecular method. Six (10%) out of the 60 collected vegetable samples tested positive through nested PCR amplification of B1 gene. As for the oyster samples, four (9.09%) out of the 44 collected pooled samples were positive for T. gondii. Phylogenetic analyses revealed all the DNA sequences retrieved from positive samples clustered with T. gondii with a virulent Type 1 genotype (accession no: KX270388). Further studies should be done to identify the exact genotypic profiles of the T. gondii detected in the vegetable and oyster samples to infer pathogenicity and possible sources of contamination. Our findings suggest possible transmission patterns of T. gondii oocysts as a potential health threat to consumers.