[Comparative antibacterial activity of carbapenems against P. aeruginosa (2)]

Susceptibility testing of 288 clinical isolates of P. aeruginosa in 2000 was performed by the disk diffusion method with observation at regular time course. Detailed analysis of the shape of the zones of inhibition gave interesting results, i.e. double zone of inhibition was found in MEPM specifically, unlike BIPM and IPM. The incidence was 50%. Moreover same phenomenon was detected in CAZ. After analyzing this phenomenon from the results of short-time-killing curve and inducibility of AmpC beta-lactamase it seems that there is a close relationship between formation of double zone of inhibition and bactericidal activity in sub-MIC drug concentration.