Effects of antibacterial agents on the elimination of 32P-labelled Escherichia coli by human polymorphonuclear cells (PMN).

Eight antibacterial agents, cephalothin, colistin, doxycycline, erythromycin, gentamicin, chloramphenicol, oxytetracycline and trimethoprim were studied in a phagocytic system using human polymorphonuclear cells (PMN) and a radio-labelled strain of Escherichia coli as test microbe. 100 micrograms/ml of either doxycycline or trimethoprim appeared to reduce the elimination of labelled products from the PMN. The effect of doxycycline was independent of heat-labile serum factors.