First molecular detection of Toxoplasma gondii in vegetable samples in China using qualitative, quantitative real-time PCR and multilocus genotyping

Toxoplasma gondii infection is becoming increasing problem in China but there is no data concerning contamination of vegetables intended for consumption with this parasite. The aim of the present study was to investigate fresh vegetables originated from open markets located in the Xining City, the Qinghai-Tibet Plateau (QTP), P.R. China for their contamination with T. gondii. A total of 279 fresh vegetable samples were collected and analysed using real-time PCR assay targeting B1 gene and multilocus genotyping. T. gondii DNA was found in 10 (3.6%) samples tested; eight of them represented T. gondii type I and remaining two T. gondii type II. The approximate level of contamination of positive vegetables samples, estimated based on quantitative real-time PCR (qPCR), ranged between less than one and 27000 T. gondii oocysts per sample, with majority not exceeding several oocysts per sample. The results of the study confirmed that T. gondii is present in vegetables offered in open markets in the Qinghai province, P.R. China; eating them unwashed and raw may therefore pose a threat to consumers. This is the first investigation describing T. gondii detection in fresh vegetables intended for consumption collected from the territory of P.R. China using sensitive molecular tools.