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

PLoS One. 2016 Dec 8;11(12):e0167995. doi: 10.1371/journal.pone.0167995. eCollection 2016.


Background: Coagulase 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.

Methods: The 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.

Results: Licheniocin 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).

Conclusions: This 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.

MeSH terms

  • Anti-Bacterial Agents / pharmacology*
  • Bacillus licheniformis / metabolism
  • Bacillus licheniformis / physiology*
  • Bacteriocins / pharmacology*
  • Biofilms / drug effects*
  • Biofilms / growth & development
  • Humans
  • Lactococcus lactis / metabolism
  • Lactococcus lactis / physiology*
  • Listeria monocytogenes / drug effects*
  • Listeria monocytogenes / growth & development
  • Microbial Sensitivity Tests
  • Staphylococcus / drug effects*
  • Staphylococcus / growth & development
  • Staphylococcus epidermidis / drug effects
  • Staphylococcus epidermidis / growth & development
  • Staphylococcus haemolyticus / drug effects
  • Staphylococcus haemolyticus / growth & development
  • Staphylococcus hominis / drug effects
  • Staphylococcus hominis / growth & development
  • Staphylococcus lugdunensis / drug effects
  • Staphylococcus lugdunensis / growth & development


  • Anti-Bacterial Agents
  • Bacteriocins
  • licheniocin 50.2, Lactococcus lactis

Grant support

This work was supported by the Ministry of Education, Science and Technological Development of Serbia, Grants No. 175039 and 173026, The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.