Susceptibility of Bacteroides non-fragilis and fusobacteria to amoxicillin, amoxicillin/clavulanate, ticarcillin, ticarcillin/clavulanate, cefoxitin, imipenem and metronidazole.
The susceptibility of 234 Bacteroides non-fragilis strains and 56 fusobacteria from 12 European centers to amoxicillin, amoxicillin/clavulanate, ticarcillin, ticarcillin/clavulanate, cefoxitin, imipenem and metronidazole was tested and related to beta-lactamase production. Beta-lactamase production was detected in 42.3 % of the Bacteroides strains and 26.8% of the fusobacteria. The MIC90 of amoxicillin for beta-lactamase-negative strains was 0.5 microgram/ml and the MIC90 of ticarcillin 2.0 micrograms/ml. In the case of beta-lactamase-positive strains the MIC90 of amoxicillin (32 micrograms/ml) and ticarcillin (16 micrograms/ml) dropped to less than or equal to 1.0 microgram/ml upon addition of clavulanate; 65.8% of these strains were susceptible to amoxicillin and 98.2% to ticarcillin, but all were susceptible when clavulanate was added. All strains were susceptible to imipenem and metronidazole, and 99.3% to cefoxitin.
Jacobs
M R
MR
Department of Pathology (Clinical Microbiology), Case Western Reserve University, Cleveland, Ohio 44106.
Spangler
S K
SK
Appelbaum
P C
PC
D000658:Amoxicillin / Q000494:pharmacology; D001439:Bacteroides / Q000187:drug effects*; D002440:Cefoxitin / Q000494:pharmacology; D019818:Clavulanic Acid; D002969:Clavulanic Acids / Q000494:pharmacology; D004338:Drug Combinations; D005673:Fusobacterium / Q000187:drug effects*; D015378:Imipenem / Q000494:pharmacology; D008795:Metronidazole / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D013982:Ticarcillin / Q000494:pharmacology
D002969:Clavulanic Acids; D004338:Drug Combinations; D008795:Metronidazole; D019818:Clavulanic Acid; D002440:Cefoxitin; D015378:Imipenem; D000658:Amoxicillin; D013982:Ticarcillin