Susceptibility of Streptococcus mutans and Streptococcus sobrinus to antimicrobial agents after short-term oral chlorhexidine treatments.
Effects of three different types of short-term applications (1-3 times during 1 week) of chlorhexidine (1 or 40%) on the susceptibility of 863 clinical isolates of Streptococcus mutans and 53 isolates of Streptococcus sobrinus from 58 subjects were studied. Chlorhexidine-resistant isolates were not found either before or after the treatment. The minimum inhibitory concentrations (MICs) to chlorhexidine of all isolates of S. mutans were < or = 1 microgram/ml, and of S. sobrinus < or = 2 micrograms/ml. S. mutans and S. sobrinus were also susceptible to ampicillin, penicillin, cefuroxime, and tetracycline. In conclusion, different short-term chlorhexidine regimens do not induce resistance in S. mutans or S. sobrinus and, furthermore, these species have so far retained their susceptibility to common antibiotics.
Järvinen
H
H
Antimicrobial Research Laboratory, National Public Health Institute, Turku, Finland.
Pienihäkkinen
K
K
Huovinen
P
P
Tenovuo
J
J
D000667:Ampicillin / Q000494:pharmacology; D000668:Ampicillin Resistance; D002444:Cefuroxime / Q000494:pharmacology; D002710:Chlorhexidine / Q000494:pharmacology*; D004352:Drug Resistance, Microbial / Q000502:physiology*; D006801:Humans; D008826:Microbial Sensitivity Tests; D010403:Penicillin Resistance; D010406:Penicillins / Q000494:pharmacology; D013295:Streptococcus mutans / Q000187:drug effects*; D016986:Streptococcus sobrinus / Q000187:drug effects*; D013752:Tetracycline / Q000494:pharmacology; D013753:Tetracycline Resistance
D010406:Penicillins; D000667:Ampicillin; D013752:Tetracycline; D002444:Cefuroxime; D002710:Chlorhexidine