Outer membrane proteins of Klebsiella pneumoniae after exposure to ciprofloxacin.

Suppression of bacterial growth of two Klebsiella pneumoniae strains after a short time exposure to ciprofloxacin at suprainhibitory concentrations was found (postantibiotic effect-PAE). PAEs induced by ciprofloxacin at 2 x MIC were 4.1 h and 5.3 h for the strains tested, the concentration of 4 x MIC manifested a suppression of the bacterial growth which lasted 5.9 h and 6.3 h. Delay of regrowth of K. pneumoniae strains exposed to suprainhibitory concentrations of quinolones was shown also by other authors. New information concerning the outer membrane protein profile of K. pneumoniae after PAE has been found. SDS-PAGE analysis revealed that outer membrane protein patterns isolated from K. pneumoniae strains treated with a suprainhibitory concentration of ciprofloxacin did not show apparent changes as compared to controls.