THE PREVALENCE OF INDUCIBLE P-LACTAMASE IN CLINICAL ISOLATES OF YERSlNIA ENTEROCOLlTlCA

Summary In a prevalence study, 100 clinical isolates of Yersinia enterocolitica belonging to biotypes lA, 3 and 4 isolated in Australia were examined for the induction of /3-lactamase in broth at 28OC using imipenem as an inducer. An increase in /3lactamase activity ranging from 15 to 93 fold was observed with all 36 isolates of biotypes 1A and 3 confirming that both enzyme B and enzyme "B-like" in biotype 3 and biotype 1A Yersinia enterocolitica were readily inducible. By contrast, imipenem failed to induce /3-lactamase in any of the 64 isolates of Yersinia enterocolitica belonging to biotype 4.