ISOLATION, IDENTIFICATION AND ANTIBIOTIC SENSITIVITY OF ESCHERICHIA COLI AND SALMONELLA SPECIES FROM HOSPITAL WASTE WATER IN DHAKA CITY

Abstract

The use of antibiotics in the hospitals for patient care, and disinfection is a global scenario, but it has become a threatening issue for all. Antibiotics are partially metabolized and residual quantities reach into hospital waste water. A cross-sectional study was conducted between January and June 2021 from different hospitals waste water to identify the Escherichia coli (E. coli) and Salmonella spp. A total of 100 samples were collected for bacteriological analysis. Bacteria were identified using morphological, cultural and biochemical characterization. The E. coli showed metallic sheen and pink colored colonies on EMB agar and MacConkey agar respectively. It was gram negative and showed small rod shaped arranged in single or pair shaped. It was noticed as positive to Indole, MR and catalase test but negative to VP test. In case of Salmonella spp, it was observed as black smooth colonies on SS agar. These bacteria were observed as short rod-shaped gram-negative bacteria. The MR and catalase test were positive but Indole and VP test were negative. The occurrence of E. coli and Salmonella spp. were 80% and 87%, respectively. The antibiotic sensitivity test indicated that the both types of isolated E. coli and Salmonella spp. were highly resistant to tetracycline (100%). Besides, E. coli was resistant to ampicillin (93.75%) and sensitive to ciprofloxacin (65%), streptomycin (62.5%) and gentamycin (93.5%) but Salmonella spp. was highly resistant to ampicillin (100%) and sensitive to ciprofloxacin (73.86%), gentamycin (79.54%) and streptomycin (34%). Hospital waste water contained antibiotic resistant bacteria that was reported as alarming voice to public health.