Occurrence of extended spectrum beta lactamase (ESBL) producing gram-negative bacteria in wastewaters from selected hospitals in Ibadan, Oyo State, Nigeria

Abstract

As an environmental antimicrobial resistance reservoir, untreated hospital wastewater plays a crucial role in the spread of antibiotic-resistant genes. The goal of this study was to look at the genetic drivers of ESBL resistance in Gram-negative bacteria isolates from hospital wastewater in Ibadan, Nigeria. A total of 408 bacterial isolates were obtained, with 54 being chosen for Polymerase Chain Reaction (PCR) testing due to resistance to more than three antibiotic classes. All the fifty-four ESBL producers were resistant to ceftazidime, while 40 (74.07%) showed resistance to cefotaxime. Percentage resistance to azithromycin, sulfamethoxazole trimethoprim, cefotaxime and streptomycin was 59.26 %, 64.81%, 74.07% and 75.93% respectively. Twenty seven of the ESBL- producing isolates representing 50.00 % was resistant to oxacillin. Moreover, percentage resistance to ciprofloxacin and cefepime was 38.89% and 31.48% respectively. BlaTEM-1 had the highest percentage frequency of occurrence of 85.19% while blaCTX-M had the least value of 7.41%. The percentage occurrence for resistant gene blaSHV-2, and blaSHV-1, was 20.37%, and 5.56% respectively. The presence of ESBL bacteria in hospital wastewater shows the role played by the discharge of untreated hospital wastewater in the horizontal spread of antibiotic resistance genes. As a result, Nigeria's tradition of discharging untreated hospital effluent into the environment poses a serious threat to public health.