Isolation, identification and antimicrobial susceptibility pattern analysis of Escherichia coli isolatedfrom clinical samples of Bangladesh

Urinary tract infection (UTI) is one of the most common infections of the world caused by mainly Escherichia coli. The purpose of this study was to identify E. coli as causative agent of UTI in patient of different age groups and to investigate their responses against commonly used antibiotics. Altogether, 480 urine samples were analyzed by culture method. The samples were equally streaked on Blood agar, MacConkey, and Eosin Methylene Blue Agar and then incubated at 37oC for 24 hours. After 24 hours of incubation, E. coli was identified on the basis of morphological characteristics of colony on culture media. For further confirmation of the presence of E. coli, Gram staining and conventional biochemical tests were also performed. Disk diffusion method was used for susceptibility testing against seventeen different antibiotics on Muller Hinton agar. Among the 480 urine samples, 81 samples were positive for E. coli. It was found that the females were more prone to UTI than males. The result of antibiotic sensitivity test on E. coli isolates demonstrated that they were highly sensitive to Amikacin, Gentamycin, Netilmycin, Imipenem, Meropenem, Pipracillin-Tazobactam, Tobramycin, Nitrofurantoin , Azithromycin, Levofloxacin, and Ciprofloxacin. E. coli was found intermediate sensitive to third-generation Cephalosporins such as Cefixime, Cefotaxime, Ceftazidime, Ceftriaxone and least sensitive to Cotrimoxazole and Nalidixic acid. Thus, all antibiotics used in present study except Cotrimoxazole and Nalidixic acid, could be the choice for empirical treatment of UTI.