Document Type: Original Articles


1 Department of Bacteriology and Virology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran

2 Department of Bacteriology and Virology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran Shiraz HIV/AIDS Research Center, Shiraz University of Medical Sciences, Shiraz, Iran


AbstractBackground: Escherichia coli, known as a clinically significantbacteria, can cause a wide range of infections, including urinarytract infections (UTIs), blood stream infections (BSIs), andcan frequently be isolated from various clinical specimens.Evaluation of antimicrobial resistant pattern is a necessaryaction, especially about such bacteria which are frequent andlife threatening. The aim of this study was to determine thefrequency and antimicrobial resistance pattern of E. coli isolatesobtained from various clinical specimens.Methods: This retrospective study was performed within a sevenmonth period from January 2015 to August 2015 at a specializedwomen and children hospital in Shiraz, Iran. E. coli isolates wereobtained from various clinical specimens and identified usingstandard microbiological procedure. Antimicrobial susceptibilitypatterns were determined using disk diffusion method inaccordance with CLSI recommendation.Results: Of the total 130 positive cultures, the majority of E.coli isolates were obtained from urine (96=73.8%) and blood(11=8.5%) specimens. Overall, gentamicin (70.8%) was theeffective antibiotic for the tested E. coli isolates. E. coli isolatesobtained from urine specimens showed the highest resistancerates against ampicillin (84.4%) and nalidixic acid (61.5%);while they showed the most sensitivity to gentamicin (79.2%),nitrofurantoin (70.8%) and ciprofloxacin (66.7%). Moreover,the highest antibiotic resistance rates belonged to the isolatesrecovered from endotracheal tube (ETT).Conclusion: The results showed that gentamicin was the mosteffective antibiotic against E. coli infections. However, inaddition to the gentamicin, we can recommend nitrofurantoinand ciprofloxacin as the other effective agents for UTIs.


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