PRELIMINARY CHARACTERIZATION OF SALIVARICIN 1328 BIOSYNTHETIC CLUSTER, A BACTERIOCIN PRODUCED BY Lb. salivarius CRL1328, A VAGINAL ISOLATE

VERA PINGITORE E.; HEBERT E M.; SESMA F.; NADER-MACIAS M.E.

Buenos Aires

Congreso; Biolatina 2006; 2006

Abstract: Vaginal lactobacilli play an important role in the prevention of urogenital infections. Lactobacillus salivarius subsp. salivarius CRL 1328, isolated from the vaginal tract, was found to produce a bacteriocin-like with inhibitory activity against urogenital pathogens, such as Neisseria gonorrhoeae, Enterococcus faecalis and E. faecium. Since this bacteriocin could be included in a vaginal probiotic formula together with microorganisms selected by other beneficial properties, this study was aimed to know the amino acid sequence of the bacteriocin(s) produced by L. salivarius subsp. salivarius CRL 1328 and its further sobreexpression or synthetic synthesis. Degenerate primers were designed, based on known sequences of antimicrobial peptides genes. Positive results were obtained in PCR amplifications using primers for the genes coding the two peptide-bacteriocins. Different PCR strategies were used to “walk” the region adjacent to the bacteriocin genes. The cluster was amplified, cloned in TOPO-TA 2.1 vector, transformed in E. coli DH10B, and sequenced. The sequence analysis of the salivaricin 1328 locus revealed that is very similar to the bacteriocin cluster of Lb. salivarius UCC118, a strain isolated from human intestinal tract that produce a two peptide bacteriocin called ABP118. Based on the amino acid sequence, synthetic peptides were designed and a study of mechanism of action is in progress.