T. Nishihata et al., INHIBITORY EFFECT OF CLINDAMYCIN ON PRODUCTION OF BETA-LACTAMASE IN BETA-LACTAM-RESISTANT BACTERIA, Biological & pharmaceutical bulletin, 17(5), 1994, pp. 715-720
The inhibitory effect of clindamycin on beta-lactamase biosynthesis wa
s investigated in beta-lactam resistant bacteria with inducible and/or
constitutive production of the enzyme(s). Clinical isolates of Entero
bacter cloacae (E. cloacae) and Pseudomonas aeruginosa (P. aeruginosa)
were examined. Three strains of each, against which sulbactam at 8 mu
g/ml reduced the minimum inhibitory concentration (MIC) of cefoperazon
e (CPZ) at least 4 fold, were studied in greater detail. Although clin
damycin had no appreciable effect on bacteria growth at concentrations
up to 50 mug/ml, it suppressed inducible beta-lactamase biosynthesis
almost completely at a concentration of 20 mug/ml. There was also a si
gnificant reduction of constitutive enzyme biosynthesis by clindamycin
at 50 mug/ml. Thus, it was estimated that a high concentration of cli
ndamycin was required to suppress beta-lactamase biosynthesis in beta-
lactamase producing bacteria of the constitutive type.