Spontaneous resistance in Lactococcus lactis IL1403 to the lantibiotic lacticin 3147.
The ability and frequency at which target organisms can develop resistance to bacteriocins is a crucial consideration in designing and implementing bacteriocin-based biocontrol strategies. Lactococcus lactis ssp. lactis IL1403 was used as a target strain in an attempt to determine the frequency at which spontaneously resistant mutants are likely to emerge to the lantibiotic lacticin 3147. Following a single exposure to lacticin 3147, resistant mutants only emerged at a low frequency (10(-8)-10(-9)) and were only able to withstand low levels of the bacteriocin (100 AU mL(-1)). However, exposure to increasing concentrations, in a stepwise manner, resulted in the isolation of eight mutants that were resistant to moderately higher levels of lacticin 3147 (up to 600 AU mL(-1)). Interestingly, in a number of cases cross-resistance to other lantibiotics such as nisin and lacticin 481 was observed, as was cross-resistance to environmental stresses such as salt. Finally, reduced adsorption of the bacteriocin in to the cell was documented for all resistant mutants.
Guinane
Caitriona M
CM
Department of Microbiology, University College Cork, Cork, Ireland.
Cotter
Paul D
PD
Hill
Colin
C
Ross
R Paul
RP
D000327:Adsorption; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001430:Bacteriocins / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial; D013294:Lactococcus lactis / Q000187:drug effects* / Q000254:growth & development; D009113:Muramidase / Q000494:pharmacology; D009154:Mutation
D000900:Anti-Bacterial Agents; D001430:Bacteriocins; C082508:lacticin 481; D009113:Muramidase