To characterize the beta-lactamases present in ESBL-positive UTI samples from three referral hospitals in North Wales (UK) (Figure 1b), 100 bacterial strains isolated from UTI samples from each site were sub-cultured; the DNA was extracted; and the beta-lactamase genes of the blaCTX-M groups 1, 2, 9 and 8/25 were amplified using multiplex PCR and identified by DNA sequencing. The gene discussed is LACTB; the disease is bacterial urinary tract infection.