ABSTRACT
This study was undertaken to determine the beta-lactamases which are cephalosporinases that confer resistance to a wide variety of beta - lactam drugs and that may thereby create serious therapeutic problems. Forty clinical isolates of Klebsiella pneumoniae recovered from different specimens collected from Kasr Al-Aini hospital, Cairo, Egypt were tested. Klebsiella pneumoniae showed 100% resistance against amoxicillin and penicillin, followed by ampicillin/sulbactam [75%], tobramycin [72.5%], cephradine and tetracycline [70%]. In contrast it showed 90% sensitivity and intermediate susceptibility against imipenem followed by azithromycin, which showed 67.5%, ofloxacin [55%] and levofloxacin [50%]. ESBL tests were performed using the recommended methods by Clinical and Laboratory Standards Institute [CLSI] as disc diffusion method and the phenotypic confirmatory test by combination disc method showing ESBL positive results in ration of 87.5% for the first test and 90% for the second confirmatory test. Sixty percent of isolates of Klebsiella penumoniae tested using boronic acids were of class C beta-lactamases producer. Detection of AmpC or ESBLs may aid in hospital infection control and the ability of the physician to prescribe the most appropriate antibiotic, thus decreasing the selective pressure, which generates antibiotic resistance