الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 124 |  |  |
| | | from | 124 | | |
Abstract
This study was aimed to characterize the Extended-spectrum beta-lactamases among clinical isolates of members of Enterobacteracae including E.coli, klebsiella pnumoniae and proteus isolates by phenotypic method like disk diffusion method and genotypic method by polymerase chain reaction (PCR) by using of oligonucleotide primers that are specific for a β-lactamase genes.
Ninty clinial isolates obtained from different 220 clinical speciemens (155 urine, 40 blood,15 sputum and 10 pus speciemen) were collected from Zagazig University Hospitals and Al-Ahrar Educatioal Hospital.
Fifty four (60%) isolates were identified as E.coli while klebsiella pnumoniae were comprised (31.1%) of the isolates followed by proteus (8.9%).
Identification of these isolates was based mainly on culture and biochemical characters of the isolates like growth on MacCkonky ,EMB, TSI, IMViC, urease tests, motility and swarming phenomenon.
All these isolates undergo susceptibility test to both beta-lactam and non beta-lactam antimicrobial agents by disk diffusion method.
The susceptibility of E.coli isolates towards beta-lactam antibiotics showed high resistance toward ceforuxime (88.9%) followed by ceftazidime (57.4%) and revealed sensitivity(68.5%) to both ceftriaxone and aztreonam.
The susceptibility of klebsiella pnumoniae isolates showed resistanc (64.3%) to ceforuxime .while the isolates revealed sensitivity 64.3% and 60.7% respectively to cefotaxime and azteronam.
While Proteus isolates showed resistanc to cefuroxime (62.5%) and revealed senstivity (62.5%) to ceftazidime.On the other hand the susceptibility of clinical isolates to non beta-lactams showed that E.coli isolates had high senstivity to nitrofurantoin (98%) followed by gentamycin (87%) and ciprofloxacin (70.4%). while the same isolates showed resistance (68.5%) to tetracycline.
In addition, klebsiella pnumoniae isolates had high sensitivity reached about (75%) to sulphamethoxazole-trimethoprim followed by (64.3%) to gentamycin and showed high resistance toward tetracycline (85.7%) and (57.1%) to ciprofloxacin.