Molecular detection of Toxoplasma gondii in marine fish from Tunisia: First report in the Southern Mediterranean Sea
摘要
Toxoplasmosis, caused by Toxoplasma gondii (T. gondii), is a ubiquitous zoonotic parasitic disease increasingly reported in marine ecosystems, raising concerns about seafood contamination and potential human exposure. Consumption of raw or undercooked fish may therefore represent a potential risk to consumers. This study aimed to investigate the presence of T. gondii DNA in marine fish from the Tunisian coast and to assess their potential role as indicators of environmental contamination. A total of 559 specimens, representing 32 species, were collected and grouped into 100 pooled samples by species. Tissue samples (gills, skin/muscle, and intestine) were analyzed using real-time PCR. Overall, 16% (16/100) of pooled samples were tested positive for T. gondii, involving 13 fish species. Positive detections were observed in both wild and farmed fish, including caged Sparus aurata. Gill tissues showed the highest frequency of detection (9/16), followed by lower detection rates in skin/muscle (4/16) and intestinal (3/16) samples. Demersal species showed the highest number of positive pools, followed by pelagic and benthopelagic specimens. However, Carnivorous fish showed higher detection rates (36%) compared to omnivorous (31.6%) and herbivorous species (14.3%). This survey provides the first molecular evidence of T. gondii in marine fish from Tunisia and highlights the potential role of certain species as indicators of environmental contamination and passive carriers of this parasite within marine ecosystems.