| Extended-spectrum beta-lactamases (ESBLs) are extremely broad-spectrum beta-lactamase enzymes found in a variety of Enterobacteriaceae. When producing these enzymes, organisms become highly effective at inactivating various beta-lactam antibiotics. The magnitude of this threat in Israel at the outpatient level is not well known. Section 1 of this project evaluates the incidence of ESBL-producing bacteria in outpatients in our region, and analyzes the antimicrobial susceptibility pattern of those strains. A total of 2098 Gram-negative uropathogens isolated from outpatients' urine cultures were screened for ESBL. Sixty-four (3.1%) proved to be ESBL-producers. The resistance rates for ESBL-producing E. coli and Klebsiella spp were the following: ampicillin/sulbactam 63.0% and 100.0%, amoxicillin/clavulanate 34.8% and 66.7%, ciprofloxacin 43.5% and 50.0%, gentamicin 17.4% and 72.2%, nitrofurantoin 21.7% and 55.6%, and trimethoprim/sulfamethoxazole 52.2% and 58.8% respectively.; Although the risk factors for the development of ESBL-producing bacteria have been researched in the hospitalized patient, those factors have not been defined for the outpatient in the community level. In Section II, the risk factors for the development of ESBL-producing bacteria in outpatients were evaluated. Clinical data from a total of 311 non-hospitalized patients suffering from community-acquired urinary tract infection due to E. coli or Klebsiella sp. (128 ESBL-positive and 183 ESBL-negative) were obtained. Using univariate and multivariate analysis, the following were identified as independent risk factors: previous hospitalization in the last 3 months, antibiotic treatment in the last 3 months, age over 60 years, diabetes, gender (male), and K. pneumoniae infection. Among the different antibiotic classes, 2nd and 3rd generation cephalosporins, quinolones, and penicillin were identified as independent risk factors.; Due to considerable geographical variations, the performances of ESBL detection and confirmation methods must be determined in every country and location. In Section III, the sensitivity of Single Disk Diffusion Test (SDDT), Inhibitor Potentiated Double Disk (IPDD), Etest, and Aproximation Test (AT) were evaluated in a collection of 326 ESBL-positive organisms isolated in Israel, including E. coli, Klebsiella spp, Proteus spp, and Enterobacter spp. IPDD using cefotaxime and ceftazidime, or ceftazidime and cefpodoxime proved to be the best option in our country. |
