DETECTION OF MUTATIONS CONFERRING EXTENDED-SPECTRUM ACTIVITY ON SHV BETA-LACTAMASES USING POLYMERASE CHAIN-REACTION SINGLE-STRAND CONFORMATIONAL POLYMORPHISM (PCR-SSCP)

Single strand conformational polymorphism (SSCP) is a recently develop ed technique used to detect single base mutations in short PCR-generat ed amplimers. The method has been adapted and applied to differentiati on of beta-lactamase genes. Each of the five standard SHV strains used produced a unique SSCP pattern, allowing the possibility of rapid ide ntification of the SHV genes of other isolates. A clinical isolate tha t phenotypically produced SHV-5 yielded a pattern of major bands indis tinguishable from that of the SHV-5 standard strain, illustrating the applicability of this technique. We therefore report a reliable and re producible technique that can be applied to the characterisation of th e SHV beta-lactamases.