Development of resistance of some Klebsiella species isolated locally from urinary tract infection to some beta - lactam antibiotics

200 urine specimens were collected from patients with urinary tract infection and speculated for Klebsiella species. 70 specimens (35%) showed growth and 11 isolates (15.7%) were identified as Klebsiella species (K. pneumoniae, K oxytoca and K. ozaenaej. Most of locnl isolates revealed high resistance to antibiotics: Penicillin G, Ampicillin, Amoxicillin, Piperacillin, Cephalothin, Cefaclor and Cefotaxime, moderate resistance to cephalexin, Ceftazidime and Cefixim and low resistance to Augmentin, Cefoxitin an Ceftizoxime. The MICs of Amoxicillin, Piperacillin, Cephalexin and Cephalothin (512-1024) Hg/ml were higher than other antibiotics (32-512) jig/ml and 10 isolates (90.9%) produced ^-lactamase. The cations Mg2+ and Ca2+ were more affective in decreasing the ceftizoxime MICs than other cations. No significance effect of Fe3+ and Zn2+ on MICs in all concenentrations (1, 2.5, 5, 10) jig/ml while Na+ caused increasing in MICs at concentrations (0.5, 1)%.