| Summary: | We determined the phenotypic profile of multidrug-resistant (MDR) <i>Escherichia coli</i> isolated from 698 samples (390 and 308 from poultry and domestic pigs, respectively). In total, 562 <i>Enterobacteria</i> were isolated. About 80.5% of the isolates were <i>E. coli</i>. Occurrence of <i>E. coli</i> was significantly higher among domestic pigs (73.1%) than in poultry (60.5%) (<i>p</i> = 0.000). In both poultry and domestic pigs, <i>E. coli</i> isolates were highly resistant to tetracycline (63.5%), nalidixic acid (53.7%), ampicillin (52.3%), and trimethoprim/sulfamethoxazole (50.9%). About 51.6%, 65.3%, and 53.7% of <i>E. coli</i> were MDR, extended-spectrum beta lactamase-producing <i>enterobacteriaceae</i> (ESBL-PE), and quinolone-resistant, respectively. A total of 68% of the extended-spectrum beta lactamase (ESBL) producers were also resistant to quinolones. For all tested antibiotics, resistance was significantly higher in ESBL-producing and quinolone-resistant isolates than the non-ESBL producers and non-quinolone-resistant <i>E. coli</i>. Eight isolates were resistant to eight classes of antimicrobials. We compared phenotypic with genotypic results of 20 MDR <i>E. coli</i> isolates, ESBL producers, and quinolone-resistant strains and found 80% harbored <i>bla</i>CTX-M, 15% <i>aac</i>(<i>6</i>)-<i>lb</i>-<i>cr</i>, 10% <i>qnrB</i>, and 5% <i>qepA</i>. None harbored TEM, SHV, <i>qnrA</i>, <i>qnrS</i>, <i>qnrC</i>, or <i>qnrD</i>. The observed pattern and level of resistance render this portfolio of antibiotics ineffective for their intended use.
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