INVESTIGADORES
SAAVEDRA Maria Lucila
congresos y reuniones científicas
Título:
In silico genomic identificacion and analysis of enterococcal food safety molecular markers
Autor/es:
BONACINA J; SUAREZ, N; SAAVEDRA L; SESMA F
Reunión:
Congreso; Congreso Argentino de Microbiología General; 2013
Resumen:
Microorganisms of the genus Enterococcus are autochthonous lactic acid bacteria found in high number in artisanal fermented products such as cheeses and sausages. They resist technological processes and due to their metabolisms they guarantee particular organoleptic and safety properties of the final product. In addition, enterococci produce antimicrobial peptides named enterocins active against the food borne pathogen Listeria monocytogenes and spoilage microorganisms showing a great potential for biopreservation. On the other hand, despite the technological properties of this genus, they can harbor pathogenic markers and they can be resistant to antibiotics of clinical relevance. The dualistic aspects of enterococci still represent a great challenge to the food industry and constitute a vast field for scientific research. E. mundtii CRL 35 and E. faecium CRL 1879 are two strains isolated from different home-made northwestern Argentinean cheeses, extensively studied in our laboratory. The genomes of both strains were recently sequenced by next generation sequencing technologies (454 pirosequencing for CRL35 and Ion torrent for CRL1879). The aim of the present work is to in silico identify and analyze the presence of genes involved in bacteriocin production and potential virulence factors. Genomic analysis using the RAST Server, Bactibase database and Blast algorithms showed that both strains carried genes encoding antilisterial compounds. Moreover, E. faecium CRL 1879 genome revealed the presence of multiple-bacteriocin genes i.e. the biosynthetic cluster for enterocin A, enterocin B, enterocin P, enterocin SE-K4, enterocin X and a novel two component bacteriocin. Regarding E. mundtii CRL35, we confirmed that this strain contain only one bacteriocin biosynthetic cluster (enterocin CRL35) previously described in our laboratory. No virulence factors or antibiotics resistance genes were detected in both strains except ccf in E. faecium CRL1879. Microbial genomic studies have considerable impact in the discovery of novel antimicrobial compounds and represent a start point to a further functional characterization before they that can be exploited by food or pharmaceutical industries. IX