The strain (1622) was isolated from a bronchial alveolar lavage specimen and identification was carried out by the API 20NE identification system. Minimum inhibitory concentrations (MIC) of a range of antibiotics were determined by the agar dilution method.4 A cell-free extract of strain 1622 was prepared and (cid:2)-lactamase bands were detected by isoelectric focusing (IEF) on a polyacrylamide gel. Inhibitors were applied to the gel to detect enzyme inhibition. Imipenem hydrolysis was demonstrated by a microbiological assay.2 This assay was modified to increase sensitivity and quantify the activity of the enzyme.3 Curing

thank the Acute Healthcare Research Committee of the Scottish for grant number K/MRS/50/C2522 to SGBA and HKY. This supported the above work and partially funds SB.