First report of Tunisian coastal water contamination by protozoan parasites using mollusk bivalves as biological indicators

• Published in: Marine pollution bulletin Vol. 117; no. 1-2; pp. 197 - 202
• Main Authors: Ghozzi, Khemissa, Marangi, Marianna, Papini, Roberto, Lahmar, Ibtissem, Challouf, Rafika, Houas, Najoua, Ben Dhiab, Rym, Normanno, Giovanni, Babba, Hamouda, Giangaspero, Annunziata
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 15.04.2017
• Subjects: Animals; Bivalve mollusks; Bivalvia - parasitology; Cryptosporidium - isolation & purification; Cryptosporidium spp; Cyclospora - isolation & purification; Cyclospora cayetanensis; Environmental Monitoring; Giardia - isolation & purification; Giardia duodenalis; Oocysts; qPCR; Toxoplasma - isolation & purification; Toxoplasma gondii; Tunisia; Toxoplasma gondii; Cryptosporidium spp; Cyclospora cayetanensis; Bivalve mollusks; qPCR; Giardia duodenalis; Tunisia
• ISSN: 0025-326X; 1879-3363
• DOI: 10.1016/j.marpolbul.2017.01.057

In order to establish seawater contamination by emerging protozoan parasites, we used qPCR to molecularly characterize and evaluate the parasitic burden of Giardia duodenalis, Cryptosporidium spp., Toxoplasma gondii, and Cyclospora cayetanensis in 1255 wild bivalve mollusks collected along the Tunisian coasts. T. gondii, G. duodenalis and C. cayetanensis were detected in 6.9% (99% CI=1.6–12.2%) pools of Ruditapes decussatus. None of the samples were found positive to Cryptosporidium spp.; 6.6% pools of R. decussatus were positive for T. gondii Type I, 1.6% for G. duodenalis assemblage A, and 1.6% for the association T. gondii Type I/C. cayetanensis/G. duodenalis assemblage A. R. decussatus harbored up to 77500 oocysts/sample of T. gondii, up to 395 cysts/sample of G. duodenalis, and 526 oocysts/sample of C. cayetanensis. These results provide the first evidence that the Tunisian coasts are contaminated by zoonotic protozoan parasites that can constitute a direct or indirect risk for human health. •Contamination of Tunisian coastal waters by protozoan parasites is undocumented.•The presence of protozoan parasites was investigated by qPCR using mollusks as bio-sentinels.•Three species of protozoan parasites with high parasitic burdens are present along the Tunisian coasts.•Zoonotic assemblage/lineage circulating in Tunisia