Garvicins AG1 and AG2: Two Novel Class IId Bacteriocins of Lactococcus garvieae Lg-Granada

Abstract

Lactococcus garvieae causes infectious diseases in animals and is considered an emerging zoonotic pathogen involved in human clinical conditions. In silico analysis of plasmid pLG50 of L. garvieae Lg-Granada, an isolate from a patient with endocarditis, revealed the presence of two gene clusters (orf46–47 and orf48–49), each one encoding a novel putative bacteriocin, i.e., garvicin AG1 (GarAG1; orf46) and garvicin AG2 (GarAG2; orf48), and their corresponding immunity proteins (orf47 and orf49). The chemically synthesised bacteriocins GarAG1 and GarAG2 presented inhibitory activity against pathogenic L. garvieae strains, with AG2 also being active against Listeria monocytogenes, Listeria ivanovii and Enterococcus faecalis. Genetic organisation, amino acid sequences and antimicrobial activities of GarAG1 and GarAG2 indicate that they belong to linear non-pediocin-like one-peptide class IId bacteriocins. Gram-positive bacteria that were sensitive to GarAG2 were also able to ferment mannose, suggesting that this bacteriocin could use the mannose phosphotransferase transport system (Man-PTS) involved in mannose uptake as a receptor in sensitive strains. Intriguingly, GarAG1 and GarAG2 were highly active against their own host, L. garvieae Lg-Granada, which could be envisaged as a new strategy to combat pathogens via their own weapons.

Optimized recombinant production of the bacteriocin garvicin Q by Corynebacterium glutamicum

“…Activity of the class II bacteriocin pediocin PA-1 was shown to be sensitive to oxidation of a methionine residue. As GarQ contains a methionine in position 5 of the active peptide, we hypothesized that GarQ may be inactivated by oxidation of this methionine and cultivation in low oxygen conditions may reduce oxidative inactivation Garvicin AG2 is a natural variant of GarQ, in which the methionine in position 5 is changed to a phenylalanine ( Maldonado-Barragán et al, 2022 ). To test if this peptide may be protected against oxidative inactivation, we purchased a synthetic GarQ variant with the M5F amino acid exchange (GarQ M5F ) from a commercial supplier and compared its activity to native GarQ in pHluorin2 assays using L. lactis LMG2785/pNZ-pHin Lm or L. monocytogenes EGDe/pNZ-pHin Lm ( Figure 6A ).…”

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

“…Garvicins AG1 and AG2 are two novel class IId bacteriocins of L. garvieae Lg-Granada isolated from the blood of a patient with endocarditis. They exhibit antimicrobial activity against other L. garvieae strains, and AG2 can also inhibit the growth of Listeria monocytogenes, Listeria ivanovii, and Enterococcus faecalis [25]. Apparently, that the majority of bacteriocins produced by L. garvieae are narrow-spectra bacteriocins.…”

“…The most representative bacteriocin is the lactibiotic nisin, which is the rst and most widely used bacteriocin in the food preservation and there have been no reports of widespread drug resistance [8,22]. L. garvieae is a LAB and so far, various bacteriocins have been found in different L. garvieae strains, including garviecin L1-5 [23], Garvicin ML [11], Garvieacin Q [16], garvicin A [24], Garvicin KS [17,18], Garvicins AG1, and Garvicins AG2 [25]. This study reports a novel bacteriocin, garvicin-SHAMU-LG6, that was produced by L. garvieae strain SHAMU-LG6 (CCTCC No: M 2023482), and whose wide antimicrobial activity against various pathogenic bacteria as well as MDRP, and high pH and thermal stability highlight its potential as a promising clinical therapeutic drug.…”

Comprehensive Review on the Biocontrol of Listeria monocytogenes in Food Products

“…Class IId bacteriocins are linear non-pediocin like peptides. Some more recently discovered examples are garvicin A, garvicin AG1, and garvicin AG2 [ 27 ].…”