Effects of antibiotics on the adsorption of klebsiella pneumoniae to cultured cells

Abstract

A cell suspension of a Klebsiella pneunmoniae strain was given on a monolayer of HeLa cells, then adsorption of the strain in the cells was tested. In these experiments, 104-106 CFU were adsorbed within 3 hours if the cell suspension contained less than 106 CFU. When AMK was added at concentrations of 10 or 100 MIC, no multiplication of the organisms was noted after 18 and 6 hours, respectively, when tested by solid medium. When tested by a broth medium, however, the organisms were detected even 18 hours later in 100 MIC. Similar results were obtained with DOXY at 6 hours in 100 MIC. With β-lactam antibiotics 102-108 CFU and 104-105 CFU of the organisms were observed using solid and broth media, respectively. Concerning the morphological features of the organisms, no change was observed at 100 MIC of AMK when viewed under the light microscope. By scanning electron microscopy, cellular damage was observed both in the bacterial and HeLa cells, and recovery of morphological alteration was shown by the removal of AMK. Also, when treated with β-lactam antibiotics, elongation of cells and discharge of intracellular substances were observed by light microscopy. © 1988, Japanese Society of Chemotherapy. All rights reserved.