Detection of structural genes for enterocins production among enterococci isolated from french traditional fermented sausages
Résumé
In European countries, the demand for traditional food products has increased. Dry fermented sausages, mainly manufactured with pork and/or lean beef and pork fat, account for a significant part of traditional meat products. Many studies have dealt with the microbiology of traditional fermented sausages but there are few detail studies of properties of individual genera. The genus Enterococcus involved about 55 validated species. Its representants are mostly lactic acid producing; they can possess probiotic properties or produce bacteriocins (antimicrobial substances); on the other side, some strains can posess virulence factors genes. Our study has been focused on positive property-on detection of structural genes for enterocins production among enterococci isolated from French traditional fermented sausages. Enterocins are proteinaceous antimicrobial substances produced mostly by enterococci with inhibition spectrum against Gram-positive but also against Gram-negative bacteria. This study was performed in the framework of the EU project TRADISAUSAGE-QLK1-CT2002-02240; that is why also French traditional fermented meat products were analysed. Samples of products from 10 low-capacity processing units (placed in Massif-central-France) were collected. Sampling was performed from the initial meat (Z), during processing (M) and from the final product (F). Sampling and analytical methods for the microbiota analysis were based on the International Organisation for Standardisation (ISO). Enterococci were counted on M-Enterococcus agar (Merck, Germany). Fifty–three pure colonies were identified by PCR (primers) confirmed by Maldi-Tof identification system. Enterocins genes were tested by primers and PCR. Most of strains belonged to the species Enterococcus faecium, followed by E. faecalis and other not specified species. Strains survived in Oxgall bile evironment in high %. The most detected was Ent P gene (34%) followed by Ent A gene (27%) and Ent L50B (20%). The least was detected Ent B gene (19%).