Beta-lactamase stability of temocillin.

The stability of temocillin to 12 different beta-lactamase preparations was studied using high pressure liquid chromatography and was compared with that of aztreonam, cefotetan and cefotaxime. Temocillin was the most stable beta-lactam examined, being as stable as cefotetan to most of the beta-lactamases tested. However, cefotetan was hydrolysed at measurable rates by the beta-lactamase of Enterobacter cloacae P99, in contrast to temocillin which was completely stable to this enzyme. Aztreonam was hydrolysed at a slow rate by many of the preparations, being especially labile to the enzyme from Klebsiella oxytoca K1. Cefotaxime was hydrolysed at varying rates by all the preparations.