β-Lactamase Production by Intestinal Spirochaetes

SUMMARY: β-Lactamase production was demonstrated in four of nineteen strains of intestinal spirochaetes isolated from human subjects. The enzyme was preferentially active against penicillins and was inhibited by clavulanic acid; it was membrane bound and non-inducible. No plasmids were detected in the intestinal spirochaetes and the β-lactamase-production characteristic was not transferable to non-producing strains.