Prevalence, distribution and pathogenic profile ofVibrio parahaemolitycusandVibrio spp. core in shellfish (Mytilus galloprovincialisandRuditapes decussatus) collected in Sardinia (Italy): molecular fingerprinting using three pcr- based methods: BOX-pcr, REP-pcr and ERIC- pcr

The aim of our study was to investigate the prevalence and concentration ofVibrio spp. core (V.s.) andV. parahaemolyticus(V.p.) inMitylus galloprovincialis(M.g.) andRuditapes decussatus(R.d.), using phenotypic and PCR methods. Detection ofV.s. core have been carried out in samples (before and after depuration) of shellfish harvested in three areas of Sardinia (Italy), from April 2011 to May 2012. The prevalence ofV.s. was 72.3% and 76.7%, and 90.0% and 78.5%, respectively inM.gandR.d., before and post depuration. A selection of the strains were submitted to PCR for species identification ofV.s.. A prevalence of 2%, 0.40%, and 24 % ofV. cholera,V. vulnificusandV.p., were respectively showed. The prevalence ofV.p. was higher inR.d. (61%) than inM.g. (23%). Only 2/114 strains (1.8%) of.V.p. were positive fortdh+/trh- factors, and the same fortdh-/trh+, while none wastdh+/trh+.V.p. strains were submitted to three fingerprinting PCR-based methods (ERIC-, REP- and BOX-PCR). Two clusters were obtained using all the techniques. Most of the strains were grouped in one of these, especially those isolated from clams in autumn, from the same area. Our findings confirm the potential human health risk associated with the presence of pathogenicV.s. in shellfish, and that vibrios shows a different feedback to the depuration processes. Then specific measures are needed to prevent the presence of naturally occurring bacteria in the molluscs.