Interaction of subminimal inhibitory concentrations of clindamycin and gram-negative aerobic organism: Effects on adhesion and polymorphonuclear leukocyte function

The effect of pre-incubation of Pseudomonas aeruginosa, Klebsiella pneumoniae and Proteus mirabilis with sub-inhibitory concentrations (sub MICs) of clindamycin on the adherence of these organisms was studied. Culturing these organisims in the presence of clindamycin (4 mg/l) resulted in significant enhancement of adherence for Ps. aeruginosa and Pr. mirabilis and decreased adherence for K. pneumoniae . Furthermore, the effect of pre-exposure to clindamycin on polymorphonuclear leukocyte (PMNLs) function against these organisms was determined. Filtrates of Pr. mirabilis pre-exposed to clindamycin promoted PMNL chemotaxis. No effect on chemotaxis PMNL phagocytosis for all the organisms was increased after they were pre-exposed to clindamycin.