Abstract: Urinary Tract Infection (UTI) is one of the most common bacterial infections and E.coli is known to be as an important cause of UTIs. Because bacterial resistances to antibiotics are increasing, therefore a reliable method of antimicrobial resistance detection is important in treatment of UTIs. The objective of the present study is to evaluate and compare the performance of disk diffusion agar with E.test for antimicrobial susceptibility testing of E.coli isolated from UTI. This study was carried out on 250 isolates of E.coli from patients with UTI in Shariati Hospital of Tehran University of Medical Sciences in year 2005. Antibiotic susceptibility testing was performed by disk diffusion method (Iranian and Italian) for Trimetoprim sulfhamethoxazole, Gentamysin, Ceftazidim, Nitrofurantoin and Ciprofluxacin and Minimum Inhibitory Concentration (MIC) determination was performed by E.test for the same set of antimicrobial. All tests were performed on Muller Hinton agar. The results of this study show that disk diffusion agar may be used as a preliminary screen for antibiotic susceptibility testing of E.coli and is less sensitive than Italian disk diffusion and E.test. By comparison of 3 above mentioned methods E.test is the most sensitive and shows the effective dose of antibiotic for treatment and prevention of antibiotic resistance. Comparison of E.test with Iranian disk diffusion agar showed paramount differences in antibiotic agreement (max 37.8 %) these differences in case of Ceftazidim and Gentamysin were, respectively 76.8 and 62.2% whereas comparison of E.test with Italian disk diffusion agar showed less difference of antibiotics agreement (max 11.2%).
Y. Erfani , H. Choobineh , R. Safdari , A. Rasti and S. Alizadeh , 2008. Comparison of E. Test and Disk Diffusion Agar in Antibiotic Susceptibility of E. coli Isolated from Patients with Urinary Tract Infection in Shariati Hospital (Iran). Research Journal of Biological Sciences, 3: 24-27.