Susceptibility patterns and characterization of beta-lactamases in clinical isolates of Bacteroides fragilis.
Strains of Bacteroides fragilis isolated from clinical specimens are known to be frequently resistant to penicillins or cephalosporins. The production of beta-lactamases is the major mechanism in this resistance. Up to now at least five types of beta-lactamase enzymes have been described in the Bacteroides fragilis group. The purpose of this study was to evaluate the susceptibility to different antibiotics and the prevalence of the beta-lactamase types among 100 Bacteroides fragilis strains isolated from clinical specimens in Italy. MICs of 11 antibiotics were determined by the reference agar dilution method and by the new E test (AB Biodisk, Sweden). Results showed an acceptable correlation between the MICs determined for most strains, although those obtained by the E test tended to be lower. In the beta-lactam resistant strains the enzyme activity and isoelectric points were determined on crude enzyme extract.
Bacteriology and Medical Mycology Department, National Institute of Health, Rome, Italy.
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Mastrantonio
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Spigaglia
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Sebastianelli
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001442:Bacteroides Infections / Q000188:drug therapy / Q000382:microbiology*; D001441:Bacteroides fragilis / Q000187:drug effects* / Q000201:enzymology / Q000302:isolation & purification; D004352:Drug Resistance, Microbial; D006801:Humans; D007558:Italy; D008826:Microbial Sensitivity Tests; D018440:beta-Lactam Resistance; D001618:beta-Lactamases / Q000302:isolation & purification / Q000378:metabolism*
D000900:Anti-Bacterial Agents; D001618:beta-Lactamases