Prevalence of pathogenic E. coli in herbal production had been studied by many investigations, but a few of them focused on its resistant to antibiotics. Throughout this paper, we will evaluate the minimum inhibitory concentration (MIC) of antibiotics against some E. coli strains and study the antibiotic’s time-kill against most resistant strain. Obtained results revealed that the highest MIC of tested antibiotics was observed with ampicillin and cefuroxime against E. coli-WW-4 and E. coli-SPWW-6, which attained to 512 μg/ml. While the MIC of ampicillin reached to 128 μg/ml against E. coli-SWW-20 &E. coli-LWW-8 and reached to 16 μg/ml with cefuroxime against E. coli-SWW- 20 &E. coli-LWW-8. The second highest MIC of tested antibiotic in the present study was observed with doxycycline against E.coli-SWW-20 and E.coli-SPWW-6, which reached to 256 μg/ml, while it decreased to 16 μg/ml against E. coli-WW-4 and E. coli-LWW-8 (Fig, 1). Ciprofloxacin recorded the third MIC in the current investigation, which reached to 128 μg/ml against E. coli-WW-4 and E. coli-SPWW-6,but it dropped to 16 μg/ml against E. coli-SWW-20 &E. coli-LWW-8. MICs of other tested antibiotics ranged from 16- 32μg/ml. E. coli-SPWW-6 was the most resistant strain, which could tolerant (for 8h at least) of 2xMIC of ampicillin, cefuroxime, ciprofloxacin or doxycycline
