ENHANCED SUSCEPTIBILITY OF ESCHERICHIA-COLI PRETREATED WITH RP7293 TOLEUKOCYTE ACTIVITY - COMPARISON WITH OTHER ANTIMICROBIAL AGENTS

Antimicrobial agents may interact with polymorphonuclear leukocytes an d directly modify the leukocyte functions, or bacteria can be modified by the antimicrobial agents causing them to be treated differently by phagocytic cells. Brief exposure of bacteria to high levels of antimi crobials can affect their interaction with leukocytes. The susceptibil ity of Escherichia coli to phagocytosis and killing by human polymorph onuclear leukocytes in the presence of normal human serum following tr eatment with RP7293, a new natural streptogramin, was examined, and a comparison made with clavulanic acid/amoxicillin, ciprofloxacin and fo sfomycin. Pretreatment of E. coli for 10 min with 4 x MIC of RP7293 cl early sensitized the bacteria to leukocytic killing in the presence of normal human serum (10% v/v).