Antimicrobial susceptibility of periodontopathogenic bacteria.
OBJECTIVE
The aim of this study was to evaluate the resistance profiles of Aggregatibacter (Actinobacillus) actinomycetemcomitans, Porphyromonas gingivalis and Prevotella intermedia/Prevotella nigrescens and to detect possible changes in antibiotic resistance over the time period of 1991-2005.


METHODS
A. actinomycetemcomitans (125 strains), P. gingivalis (152 strains) and P. intermedia/P. nigrescens (326 strains) isolated during the years 1991-2005 were tested for their susceptibility to amoxicillin/clavulanic acid, clindamycin, metronidazole, phenoxymethylpenicillin and tetracycline using the Etest.


RESULTS
No antibiotic resistance was detected in P. gingivalis, whereas a few isolates of P. intermedia were not susceptible to clindamycin (0.9%), phenoxymethylpenicillin (13.5%) or tetracycline (12.6%). Amoxicillin/clavulanic acid, tetracycline and metronidazole were the most effective antibiotics against A. actinomycetemcomitans with 0%, 0.8% and 20.8% non-susceptible isolates, respectively. However, 88% of the A. actinomycetemcomitans isolates were non-susceptible to phenoxymethylpenicillin and 88% to clindamycin. When strains isolated in the years 1991-94 were compared with those isolated in the years 2001-04, there was no statistically significant difference in the percentage of A. actinomycetemcomitans strains non-susceptible to clindamycin, metronidazole or phenoxymethylpenicillin, or in the percentage of P. intermedia strains non-susceptible to phenoxymethylpenicillin or tetracycline (P > 0.4 each).


CONCLUSIONS
Increasing antibiotic resistances in periodontopathogenic bacteria are not yet a problem in the Northern part of Switzerland.
Kulik
Eva M
EM
Institute for Preventive Dentistry and Oral Microbiology, Dental School, University of Basel, Hebelstrasse 3, CH-4056 Basel, Switzerland. eva.kulik@unibas.ch
Lenkeit
Krystyna
K
Chenaux
Stephan
S
Meyer
Jürg
J
D016976:Aggregatibacter actinomycetemcomitans / Q000187:drug effects*; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001438:Bacteroidaceae / Q000187:drug effects*; D024901:Drug Resistance, Multiple, Bacterial / Q000502:physiology*; D008826:Microbial Sensitivity Tests; D010510:Periodontal Diseases / Q000382:microbiology; D013997:Time Factors
D000900:Anti-Bacterial Agents