Molecular detection and genetic characterization of Toxoplasma gondii in goats’ milk and aborted goat kid tissues from Pakistan

Abstract

Toxoplasmosis is one of the most widespread foodborne diseases in humans and one of the major abortive pathogens in small ruminants. In South Punjab, Pakistan, the goat sector is pivotal in the economy and goat milk is commonly consumed raw. The aim of our study was to investigate the prevalence of Toxoplasma gondii DNA in goat milk and to genotype any isolates; additionally, the prevalence and genotype of T. gondii in aborted goat kid foetuses were investigated. From three farms, previously identified as highly seropositive, milk samples were collected from 40 goats at three different lactation intervals: 15–30, 90, and > 120 days after parturition (360 samples in total). Foetal brain and placenta tissue samples were also collected from three aborted goats. A 162 bp fragment of the 529-bp repeat element was targeted for detection of Toxoplasma DNA by real-time PCR. Positive samples were genotyped using nested-PCR targeting four genetic markers (GRA6, SAG1, 5’-SAG2, CS3). T. gondii DNA was detected in 14 milk samples (3.9 %), with higher detection in samples >120 days lactation stage (6.7 %). Between farm detection ranged from 2.5 % to 5.8 %. All aborted tissues were positive, except one foetal brain tissue (83.3 %). DNA isolates revealed type II in all samples, except one milk sample, and four aborted tissues, with either type I or III. Our results highlight that consumption of raw milk poses a potential risk to the health of consumers in this region, and the importance of implementing sanitary and/or management measures among herds to reduce Toxoplasma transmission.