EFFECTS OF MICS AND SUB-MICS OF ANTIBIOTICS ON PRODUCTION OF CAPSULARPOLYSACCHARIDE OF KLEBSIELLA-PNEUMONIAE

In the present study, we examined whether MICs and sub-MICs of antimic robial agents belonging to two different classes, ciprofloxacin and ce ftazidime, were able to influence the production and release of cell-a ssociated and soluble (extracellular) capsular polysaccharide (CPS), r espectively, in a heavily encapsulated strain of Klebsiella pneumoniae (B5055). Using a CPS-specific enzyme-linked immunosorbent assay, we f ound that the amount of cell-associated CPS increased in a dose depend ent manner by more than 10-fold under the influence of the MIC of ceft azidime and by more than 100-fold under the influence of the MIC of ci profloxacin. The largest amounts of CPS were measured by using the MIC of either antibiotic substance. Electron microscopic studies showed t hat the diameter of the capsule was significantly increased compared w ith the diameter for untreated controls. Thus, both antimicrobial agen ts genuinely stimulated CPS production.