First Molecular and Phylogenetic Identification of Toxoplasma Gondii in Sheep Liver Intended for Human Consumption in Northern Tunisia.

Abstract

The aim of this study was to estimate the molecular infection prevalence of Toxoplasma gondii in sheep liver tissues destined for human consumption. A total number of 224 liver tissues were collected from slaughtered sheep in Sejnane slaughterhouse (Northwest Tunisia). PCR was used to detect T. gondii DNA in liver tissues followed by phylogenetic analysis of amplicons. The phylogenetic tree was then constructed to compare the partial sequences of the ITS1 gene with GenBank sequences.The overall molecular prevalence of T. gondii in sheep livers was 25% (56/224). The highest molecular prevalence of T. gondii was recorded in sheep aged of less than one year old (27.3%; 52/190). Infection prevalence was significantly higher in Noire de Thibar breed (33%; 17/51) compared to other breeds (p = 0.023). There were no differences depicted according to sheep's gender. The T. gondii sequences obtained in the present study (GenBank accession numbers: OR509829 and OR509830) were 98.40-100% homologous to T. gondii sequences published in the GenBank. These results highlight a high level of T. gondii contamination of tissues destined for human consumption. Further studies are needed to improve our knowledge on different genotypes of T. gondii that infect Tunisian sheep population.