Determinación de los subtipos de Toxoplasma gondii en muestras de lechuga (Lactuca sativa l.) del mercado América de Ambato

Abstract

Toxoplasma gondii is a parasite that causes ocular toxoplasmosis, a zoonosis that affects one-third of the world's population and significantly harms pregnant women and immunocompromised individuals. It has been shown to have several routes of transmission, mainly related to cat feces and undercooked meat. However, there are also routes of transmission through raw vegetables, especially green leafy vegetables such as lettuce (Lactuca sativa L). In Ecuador, there is no information on the presence of this parasite in vegetable matrices, nor on its molecular characterization. The objective of this research was to determine the presence of T. gondii in lettuce sold in the América market in Ambato and to identify whether it belongs to subtype II or III by amplifying the SAG2 gene and using nested PCR. A descriptive and exploratory analysis was carried out, in which 21 samples from seven market stalls were analyzed. Eleven of these samples were identified microscopically, and seven of them showed molecular evidence of the presence of T. gondii (33, percent). However, none of the samples were compatible with subtypes II or III, suggesting that non-archetypal strains of T. gondii may be circulating in the city. In conclusion, the study determined the presence of T. gondii in lettuce samples and provides preliminary evidence on the genetic variability of the parasite, laying the groundwork for future research.