RESISTANCE TO BETA-LACTAM ANTIBIOTICS IN BACTEROIDES SPP

Bacteroides spp., particularly B. fragilis, are well-recognised bacter ial pathogens. Production of the typical beta-lactamases of Bacteroide s restricts the therapeutic use of beta-lactam agents mainly to the be ta-lactamase inhibitor combinations and carbapenems. These compounds h ave the advantage of broad-spectrum activity and the ability to combat polymicrobial infections. Resistance of Bacteroides spp. to beta-lact am antibiotics appears to be increasing, largely because of an overall increase in beta-lactamase activity. There has been a rise in the pre valence of isolates showing high-level production of typical Bacteroid es beta-lactamases and an increase in reports other potent beta-lactam ase types. In the case of B. fragilis, metallo-enzymes are a particula r threat to current therapeutic practice, as they are not inhibited by common beta-lactamase inhibitors and are able to hydrolyse carbapenem s. The presence of permeability barriers may confer low-level beta-lac tam resistance and supplement the effect of activity. There beta-lacta mase are also sporadic reports of loss of beta-lactam activity because of reduced affinity of the penicillin-binding proteins.