Occurrence of extended spectrum beta lactamase (ESBL) producing Escherichia coli in wastewater from two hospitals in Akure

Document Type : Original Article


Department of Microbiology, School of Life Sciences, Federal University of Technology, Akure, Nigeria


Background and rationale: Hospital wastewater is heavily contaminated with different microorganisms, resulting in a major public health threat in the developing world. This study was conducted to detect the presence of extended spectrum beta lactamase (ESBL) producing Escherichia coli (E. coli) in hospital wastewater of University of Medical Science (UNIMED) teaching hospital and University health center FUTA. Methods: Wastewater was collected from outlets in different wards, laboratories, laundry, and pipe borne water was collected as a control. The wastewater underwent bacteriological analysis using membrane filtration, identifying all bacteria isolates based on cultural, morphological, and biochemical characteristics. Zones of inhibition were interpreted to screen E. coli isolates for antibiotic susceptibility. Molecular detection of ESBL in E. coli isolates survivability at various pH, temperature, and salt concentrations were examined as well. Results: It was observed that the total bacterial counts in wastewater collected from UNIMEDTH and FUTA Health Center ranged from 51.96±0.76 cfu/ 100 ml (tap water) to 865.44±2.06 cfu/ 100 ml (Microbiology Laboratory) and 74.77±0.21 cfu/ 100 ml (nurse station) to 416.41±2.86 cfu/ 100 ml (Wound treatment ward) respectively, while the total coliform counts in UNIMED and FUTA health centre ranged from 4.40±0.07 cfu/ 100 ml (tap water) to 375.32±1.33 cfu/ 100 ml  (Microbiology Laboratory) and 5.54±0.11 cfu/ 100 ml (tap water) to 80.41±0.48 cfu/ 100 ml (doctors’ station) respectively. The least and most frequent bacterial isolates were Aeromonas hydrophila and E. coli respectively. Septrin, chloramphenicol, amoxicillin, augmentin and gentamicin had lower zones of inhibition against E. coli isolates. Conclusion: This study revealed that hospital wastewater could serve as an important source for exposure and dissemination of ESBL producing E. coli, which could pose a health risk to the people in the hospital environment and surrounding water bodies.


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