Licheniocin 50.2 and Bacteriocins from Lactococcus lactis subsp. lactis biovar. diacetylactis BGBU1-4 Inhibit Biofilms of Coagulase Negative Staphylococci and Listeria monocytogenes Clinical Isolates

Abstract

BackgroundCoagulase negative staphylococci (CoNS) and Listeria monocytogenes have important roles in pathogenesis of various genital tract infections and fatal foetomaternal infections, respectively. The aim of our study was to investigate the inhibitory effects of two novel bacteriocins on biofilms of CoNS and L. monocytogenes genital isolates.MethodsThe effects of licheniocin 50.2 from Bacillus licheniformis VPS50.2 and crude extract of bacteriocins produced by Lactococcus lactis subsp. lactis biovar. diacetylactis BGBU1-4 (BGBU1-4 crude extract) were evaluated on biofilm formation and formed biofilms of eight CoNS (four S. epidermidis, two S. hominis, one S. lugdunensis and one S. haemolyticus) and 12 L. monocytogenes genital isolates.ResultsLicheniocin 50.2 and BGBU1-4 crude extract inhibited the growth of both CoNS and L. monocytogenes isolates, with MIC values in the range between 200–400 AU/ml for licheniocin 50.2 and 400–3200 AU/ml for BGBU1-4 crude extract. Subinhibitory concentrations (1/2 × and 1/4 × MIC) of licheniocin 50.2 inhibited biofilm formation by all CoNS isolates (p < 0.05, respectively), while BGBU1-4 crude extract inhibited biofilm formation by all L. monocytogenes isolates (p < 0.01 and p < 0.05, respectively). Both bacteriocins in concentrations of 100 AU/mL and 200 AU/mL reduced the amount of 24 h old CoNS and L. monocytogenes biofilms (p < 0.05, p < 0.01, p < 0.001).ConclusionsThis study suggests that novel bacteriocins have potential to be used for genital application, to prevent biofilm formation and/or to eradicate formed biofilms, and consequently reduce genital and neonatal infections by CoNS and L. monocytogenes.

A review on Lactococcus lactis: from food to factory

“…Other recent studies have shown the potential of L. lactis in bacteriocin production as a bio-preservative against Listeria monocytogenes [52, 53] and these bacteriocins have been found useful also for clinical applications [54] via prevention/reduction of biofilm formation. LAB bacteriocins are antimicrobial peptides which have been ribosomally synthesized at transcriptional and post-transcriptional levels; this confers auto-immunity to the producer strain [55].…”

Lactolisterin BU, a Novel Class II Broad-Spectrum Bacteriocin from Lactococcus lactis subsp. lactis bv. diacetylactis BGBU1-4

“…lactis bv. diacetylactis BGBU1-4 is broad, with the strain inhibiting different strains of Lactococcus, Lactobacillus, Enterococcus species, and some pathogenic strains (16). Standard biochemical methods confirmed the proteinaceous nature of the antimicrobial agent, as it was found to be sensitive to proteinase K and pronase E. In addition, it was active against B464, a mannose phosphotransferase (Man-PTS) deletion mutant derivative of IL1403 (17), suggesting that Man-PTS is not a receptor for its antilisterial activity.…”

“…diacetylactis BGBU1-4 strain produces at least two bacteriocins (21)(22)(23). The crude extract from the cell-free supernatant of strain BGBU1-4 inhibited growth and reduced the 24-h-old biofilms formed by clinical isolates of Listeria monocytogenes and coagulase-negative Staphylococcus spp., while the prevention of biofilm formation was demonstrated for L. monocytogenes clinical isolates (16). The genes for the production of the bacteriocin lactolisterin BU were found to be located on plasmid pBU6, which is not unusual (22)(23)(24)(25), but the results of assays with plasmid-cured derivatives of strain BGBU1-4 suggested that its broad-spectrum antimicrobial activity is a consequence of the production of at least two bacteriocins.…”

“…lactis bv. diacetylactis BGBU1-4 inhibited growth and biofilm formation and reduced the 24-h-old biofilms of coagulase-negative staphylococci and Listeria monocytogenes clinical isolates (16). The objective of this work was to purify and biochemically and genetically characterize the broad-spectrum bacteriocin lactolisterin BU, produced by L. lactis subsp.…”

Fighting biofilms with lantibiotics and other groups of bacteriocins

“… 121 Finally, an interesting study recently reported the efficacy of the class II unmodified bacteriocin licheniocin 50.2 against biofilms of L. monocytogenes as well as against coagulase-negative Staphylococcus (CoNS) biofilms. 122 CoNS are important clinically and amongst the most common CoNS pathogens are S. epidermidis , S. haemolyticus , S. saprophyticus and S. lugdunensis . 123 – 126 Cirkovic and co-workers tested the efficacy of the two new bacteriocins against twelve L. monocytogenes and eight CoNS strains.…”