Garvicin-SHAMU-LG6, A Novel Bacteriocin from Lactococcus garvieae That Exert Broad Antimicrobial Activity Against Drug-Resistant Pathogens

Abstract

Background Accelerating growth and global expansion of antimicrobial resistance has deepened the demand for discovery of novel antimicrobial agents. Bacteriocins have attracted increasing interest because of their high efficiency, low toxicity and being not easy to cause drug resistance. This study aims to investigate a novel broad-spectrum bacteriocin, contributing to the pharmaceutical fields. Results From a human urine specimen, we isolated a strain thatproduced a novel broad-spectrum bacteriocin, which was identified as Lactococcus garvieae SHAMU-LG6. The bacteriocin, termed garvicin-SHAMU-LG6. The Oxford cup methoddemonstrated it could inhibit the growth of various clinically pathogenic and multidrug-resistant pathogens (MDRP). Whole genome sequencing analysis found a putative gene cluster, that shared 10% similarity with the most similar known bacteriocin cluster. In addition, the cell-free supernatant (CFS) of L. garvieae SHAMU-LG6 exerts antimicrobial activity against S. aureus by disrupting the integrity of bacterial cells. Furthermore, garvicin-SHAMU-LG6 was preliminary purified from the CFS of L. garvieae SHAMU-LG6. Its crude extraction showed good pH (pH 3 to 11) and heat stability (30℃ to 121℃) and resistance to the digestion of chymotrypsin, trypsin, proteinase K, and bromelain. Conclusions All these studies suggested that garvicin-SHAMU-LG6 has the potential to be used as a therapeutic drug against pathogenic bacteria as well as MDRP in the food and pharmaceutical fields.