Lacticin 3147 displays activity in buffer against Gram-positive bacterial pathogens which appear insensitive in standard plate assays

Lacticin 3147 is a broad-spectrum bacteriocin produced by Lactococcus lacti s subsp. lactis DPC3147, which has been shown to be active against a range of food-borne bacteria. The reported inhibitory range for lacticin is exten ded to include methicillin-resistant Staphylococcus aureus, vancomycin-resi stant Enterococcus faecalis, penicillin-resistant Pneumococcus, Propionibac terium acne and Streptococcus mutans. This extended host range is not obvio us from traditional agar plate-based methods, but reductions in bacterial c ell numbers by up to 6 log(10) cfu ml(-1) was observed after 2 h in time-ki ll curve studies conducted in broth, suggesting that the bacteriocin may ha ve potential as a therapeutic agent in the treatment of human infections.