الفهرس Only 14 pages are availabe for public view
 |  | from | 129 |  |  |
| | | from | 129 | | |
Abstract
Serratia marcescens was once considered a non-pathogenic microorganism is now a known opportunistic pathogen. Nosocomial infections caused by this organism are often hard to treat because of both the intrinsic and acquired resistance to multiple groups of antimicrobial agents. The red pigment characteristic of S. marcescens exact association with multi-drug resistance is still unclear. The overall aim of this study was to understand the association between pigment production and multi-drug resistance in environmental and clinical isolates. Twenty three isolates, 18 clinical and five environmental isolates were collected. Isolates were identified morphologically, microscopically, biochemically and genetically. Antimicrobial susceptibility revealed that S. marcescens isolates exhibited maximal resistance against amoxicillin, amoxicillin-clavulanic acid, cephradine, colistin, ampicillin-sulbactam, and erythromycin. Meanwhile, isolates showed variable sensitivity toward cefoxitin, ceftriaxone, ceftazidime, cefotaxime and cefepime.all isolates were completely sensitive toward gentamicin, sulfamethoxazole-trimethoprim, meropenem, aztreonam, and ciprofloxacin. The resistance toward Ý-lactams antibiotics suggested that the isolates might possess extended spectrum beta lactamases genes (ESBL) e.g. (blaSHV-blaTEM-blaCTX-M) and/ or AmpC genes. Initial phenotypic screening for ESBL detection revealed that 14 isolates (60.8%) were phenotypic ESBL producer