Microbiological and chemical evaluation of Helix spp. snails from local and non-EU markets, utilised as food in Sardinia

Abstract

With this study, 28 pools of snails of the genus <i>Helix</i>, respectively <i>Helix aspersa</i> (n=24) and <i>Helix vermiculata</i> (n=4) were analysed. They were taken from snail farming and stores. The snails were from Sardinia, other regions of Italy, and from abroad. All the samples were examined as pool looking for these microbiological target: <i>Salmonella</i> spp., <i>Listeria monocytogenes</i>, <i>Escherichia coli</i> O157, <i>Clostridium perfringens</i>, Norovirus and Hepatitis A Virus (HAV). In the same pools, the concentration of cadmium and lead by inductively coupled plasma mass spectrometry was also determined. The levels of these heavy metals were quite high, especially for cadmium. Two samples were positive for <i>Salmonella</i> spp., while no sample was positive for <i>Escherichia coli</i> O157, HAV and Norovirus. Two samples were positive for <i>Clostridium perfringens</i> and 8 for <i>Listeria monocytogenes</i>. The microrganisms related to <i>Listeria monocytogenes</i> were identified using biochemical techniques, then serotyped and gene sequenced by multiple loci sequence typing technique. Furthermore, antimicrobial restistence was tested on the same samples.