Presence of Contracaecum spp. in teleosts cultured and fished in Sardinia.

Abstract

This study reports the results of the finding of Contracaecum spp. during a survey on endoparasites isolated from cultured and wild fish and also from some cephalopods caught in Sardinian waters. Contracaecum spp. is a nematode belonging to the Anisakidae, and is reported to cause zoonosis in humans. Nematodes were detected after visual inspection and enzymatic digestion and then identified by morphologic observation, which was confirmed by PCR. The results show that Contracaecum spp. were found in both fish caught from sea or lagoon, and in both cultured and wild fish: 33 of the parasitized samples were wild fish (24 caught in the sea and 9 in lagoons) and 11 were cultured ones. The prevalence of Contracaecum spp. was higher in Diplodus spp. (16.0%), Sparus aurata (15.8%) and Mullus spp. (14.6%). Larvae were also found by enzymatic digestion at muscular level in 5 species, with the highest prevalence in S. aurata (10.5%). The results of this study indicate that Contracaecum spp. was present in cultured fish such as S. aurata, Diplodus spp. and Dicentrarchus labrax. All cultured fish with parasites were collected from land-based semi-intensive tanks whose water came from an adjacent lagoon. Finally, the evidence that this parasite is found in both cultured and wild fish leads us to re-consider the zoonotic potential of Contracaecum spp., in particular when one bears in mind its dimensions at the L3 stage, when it is barely visible to the human eye.