An investigation of beta-lactamases from clinical isolates of Bacteroides species.

Among a group of 116 clinically significant isolates of Bacteroides spp., 24 exhibited beta-lactamase activity greater than the basal level characteristic of most Bacteroides strains. Investigation of specific enzyme activity, iso-electric point and enzyme inhibition profiles revealed that the beta-lactamases involved could be divided into four groups, some showing similarity to those described in previous studies. Seven of the enzymes were able to hydrolyse cefoxitin, latamoxef or imipenem, and eight enzymes degraded penicillin in the presence of clavulanic acid. Five strains showed reduced susceptibility to cefoxitin, latamoxef or imipenem which was not associated with beta-lactamase activity.