A comparison of the activities of lacticin 3147 and nisin against drug-resistant Staphylococcus aureus and Enterococcus species.
OBJECTIVE
Our goal was to compare the activities of lacticin 3147 and nisin, two of the most well characterized lantibiotics, against antibiotic-resistant staphylococci and enterococci.


METHODS
We determined the MICs of lacticin 3147 and nisin for 20 strains of methicillin-resistant Staphylococcus aureus (MRSA), 20 strains of vancomycin-resistant enterococci (VRE), 6 strains of S. aureus with intermediate resistance to vancomycin (VISA), 5 strains of heterogeneous vancomycin-intermediate S. aureus (hVISA) and 4 strains of S. aureus that are susceptible to methicillin.


RESULTS
Lacticin 3147 displayed potent activity against VRE with MIC values between 1.9 and 7.7 mg/L, and varying levels of activity against S. aureus strains (MRSA, 1.9-15.4 mg/L; laboratory strains, >or=15.4 mg/L; hVISA, 15.4-30.9 mg/L; VISA, >or=61.8 mg/L). Nisin was more active against the S. aureus strains in general (MRSA and laboratory strains, 0.5-4.1 mg/L; VISA and hVISA, 2 to >or=8.3 mg/L), but was less effective than lacticin 3147 against VRE (2 to >or=8.3 mg/L).


CONCLUSIONS
Nisin is more effective against S. aureus whereas lacticin 3147 possesses greater potency against VRE. The modifications responsible for the vancomycin-resistant phenotypes of hVISA and VISA strains also provide protection against the two lantibiotics.
Piper
Clare
C
Department of Microbiology, University College Cork, College Road, Cork, Ireland.
Draper
Lorraine A
LA
Cotter
Paul D
PD
Ross
R Paul
RP
Hill
Colin
C
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001430:Bacteriocins / Q000494:pharmacology*; D016983:Enterococcus / Q000187:drug effects*; D006801:Humans; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests; D009561:Nisin / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000187:drug effects*; D020713:Vancomycin Resistance
D000900:Anti-Bacterial Agents; D001430:Bacteriocins; C082508:lacticin 481; D009561:Nisin