DECREASE IN SURFACE-CHARGE DENSITY OF KLEBSIELLA-PNEUMONIAE TREATED WITH CEFODIZIME AND ENHANCEMENT OF THE PHAGOCYTIC FUNCTION OF HUMAN POLYMORPHONUCLEAR LEUKOCYTES STIMULATED BY THE DRUG-TREATED BACTERIA

Treatment of Klebsiella pneumoniae 109 with cefodizime, ceftazidime, c efbuperazone, cefotaxime or flomoxef at a sub-minimum inhibitory conce ntration (sub-MIC) (1/4 MIC) for 1h altered its morphology. The bacter ia treated with cefodizime at sub-MICs (1/8, 1/4 MIC) enhanced the che miluminescencence (CL) of human polymorphonuclear leucocytes (PMNs), i mplying an increase in the production of active oxygen species in asso ciation with phagocytosis, whereas the tells treated with other cephal osporins at the same sub-MICs did not. Furthermore, a significant decr ease in electrophoretic mobility was induced by the bacteria treated w ith cefodizime at sub-MICs (1/8, 1/4 MIC), but other cephalosporins ne ither increased nor decreased the electrophoretic mobility significant ly. These findings suggested that cefodizime caused a morphological ch ange, with a decrease in negative surface charge density of K. pneumon iae, more easily than ceftazidime, cefbuperazone, cefotaxime or flomox ef, followed by an increase in the phagocytic activity of PMNs.