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Genetic and biochemical characterization of hyicin 3682, the first bacteriocin reported for Staphylococcus hyicus

Carlin Fagundes, Patrícia, Nascimento de Sousa Santos, Ilana, Silva Francisco, Márcia, Mattos Albano, Rodolpho, de Freire Bastos, Maria do Carmo
Microbiological research 2017 v.198 pp. 36-46
Gram-positive bacteria, Staphylococcus hyicus, amino acid substitution, antimicrobial properties, bacteriocins, coagulase negative staphylococci, food pathogens, food spoilage, milk, molecular weight, multigene family, nucleotide sequences, plasmids, siblicide
Hyicin 3682, the first bacteriocin reported for Staphylococcus hyicus, is a BsaCOL variant produced by S. hyicus 3682, a strain isolated from bovine milk. Hyicin 3682 is found in the culture supernatant, is bactericidal and its producing strain exhibits a much broader spectrum of antimicrobial activity than the producing strain of BsaCOL against several Gram-positive bacteria, which include foodborne pathogens, food-spoilage microorganisms and bacterial species of medical and veterinary importance. Sequencing of the genome of S. hyicus 3682 provided the nucleotide sequence of the entire gene cluster involved in hyicin 3682 production, which seems to be located on pRJ109, the single plasmid carried by this strain. This gene cluster is expressed and consists of 8525bp and of eight genes (hyiA, hyiB, hyiC, hyiD, hyiP, hyiF, hyiE and hyiG) encoded on the same DNA strand. The mature lantibiotic exhibits 91% identity to BsaCOL and its molecular mass was found to be ∼26Da higher due to two amino acid substitutions. S. hyicus 3682 proved to be only partially immune to its cognate bacteriocin up to 1024 AU/ml. Therefore, hyicin 3682, the first Bsa variant reported in coagulase-negative staphylococci, does exhibit antimicrobial and siblicidal activities.