Mercury accumulation in Mediterranean Fish and Cephalopods Species of Sicilian coasts: correlation between pollution and the presence of Anisakis parasites.

The aim of this study was to investigate mercury accumulation in some species, caught in Mediterranean Sea, in the period between May and December 2015, and to compare it to the presence of Anisakis parasites. The samples were examined by direct mercury analyzer (DMA-80) for their Hg levels. The metal concentration was compared to the presence or the absence of Anisakis parasites. Significant differences in Hg concentration in analysed samples were observed. The low-infested fishes contained 1-6 larvae of parasites whereas the high-infested one had 7-83 larvae.

Survey on the presence of A. simplex s.s. and A. pegreffii hybrid forms in Central-Western Mediterranean Sea.

In this study, 1029 fish and cephalopod samples came from Central-Western Mediterranean (FAO 37.1.1 and FAO 37.1.3) were analysed for Anisakidae larvae research with the aim to identify possible hybridisations between Anisakis pegreffii and Anisakis simplex s.s. species. A total of 1765 larvae were detected, with prevalence values between 8.1% and 100%. The morphologic analysis revealed characters attributable to morphotype I of Anisakis in 98.5% of the examined larvae, while 1.5% belonged to the morphotype II. PCR-based Restriction Fragment Length Polymorphism (PCR-RFLP) analysis of the entire ITS region (ITS1, 5.8S and ITS2) of nuclear ribosomal DNA (rDNA) was performed with HinfI and HhaI restriction enzymes. The majority of the larvae examined by PCR-RFLP were identified as A. pegreffii (71%), with a prevalence on horse mackerel from FAO 37.1.3, while 10% were identified as A. simplex s.s., 2% as A. physeteris and 17% as A. pegreffii×A. simplex s.s. hybrid genotype. The sequence analysis confirmed the hybridisation in the 85% of the larvae recognised as hybrid forms by PCR- RFLP, suggesting this form as the product of natural interspecific recombination due to the presence of sympatry areas. The presence of hybrid forms were mostly found in fish samples from FAO subzone 37.1.1. This is the first report of A. pegreffii x A. simplex s.s. hybrid genotype in fishes caught off the coasts of Sicily (Southern Italy). Finally, this study provided substantial information about the geographical distribution of Anisakidae family in Central-Western Mediterranean Sea.

Validation of the TrichinEasy® digestion system for the detection of Anisakidae larvae in fish products.

Anisakis and other parasites belonging to the Anisakidae family are organisms of interest for human health, because of their high zoonotic potential. Parasites belonging to this family can cause Anisakiasis, a parasitological disease caused by the ingestion of raw, infested fish products. Furthermore, evidence from the EFSA (European Food Safety Authority; EFSA 2010) has highlighted the allergological potential of nematodes belonging to the Anisakis genre. The detection and identification of Anisakidae larvae in fish products requires an initial visual inspection of the fish sample, as well as other techniques such as candling, UV illumination and artificial digestion. The digestion method consists of the simulation of digestive mechanics, which is made possible by the utilization of HCl and pepsin, according to EC Regulation 2075/2005. In this study, a new Anisakidae larvae detection method using a mechanical digestion system called Trichineasy® was developed. A total of 142 fish samples, belonging to 14 different species, were examined to validate the method. A reaction mixture with 100 g of sample, 10 g of pepsin (1:10000 NF) and 50 ml of 10% HCl at 36 ± 1°C for 20 minutes was evaluated to be the best condition for the digestion of fish samples. These parameters have also allowed the detection of viable larvae after digestion. The results confirm this instrumentation as a valuable and safe tool for the detection of Anisakidae larvae in fishery products.