Abstract

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Bacterial isolates from wastewater and sediments of the Ntanwogba open drainage system in Port Harcourt city was tested for their susceptibility to antibiotics. Wastewater samples were collected twice a week for a period of six months from February through July using standard analytical methods. Results obtained showed that the sediment samples had Escherichia coli with the highest percentage of occurrence of 23.8%, followed by Klebsiella pneumoniae and Proteus mirabilis M18 with 19% each, while Burkholderia multivorans and Pseudomonas fluoresceins had the least occurrence of 4.8% each. Wastewater samples showed that Escherichia coli also had the highest percentage occurrence of 21.2%, followed by Enterobacter asburiae and Plesiomonas shigelloides with 15.2% each, while Pseudomonas fluoresceins had the least occurrence of 6.1%. Antibiotic sensitivity of strains was conducted using the disc diffusion method. The antibiotic sensitivity test carried out on the bacterial isolates showed 100% resistance to Augmentin, Ceftazidime, Cefuroxime, Ceftriaxone, Cloxacillin and Cefi.xime. However, 2.08% were susceptible to Ciprofloxacin, 33.3% to Erythromycin, 77.8% to Gentamicin, 87.5% to Nitrofurantoin and 96.3% to Ofloxacin. Bacillus ginsengisoli was the most resistant, but sensitive to only Ofloxacin, Burkholderia multivorans was the most susceptible bacterial isolate and was susceptible to Ciprofloxacin, Gentamicin, Nitrofurantoin, Ofloxacin. This was followed by Enterobacter asburiae that was sensitive to Gentamicin, Nitrofurantoin, Ofloxacin. While Escherichia coli, Klebsiella pneumoniae, Plesiomonas shigelloides, Proteus mirabilis Ml 8, Proteus mirabilis Ml 9, Pseudomonas fluoresceins and Pseudomonas nitroreducens were all sensitive to Nitrofurantoin and Ofloxacin. The high level of resistance to antimicrobial agents recorded in this study shows that the wastewater effluents and the receiving water bodies could pose a potential health risk to the surrounding communities who depend on these water sources for various domestic activities. Therefore, proper waste water management is fundamental for maintaining public health and protecting the quality of the environment

Keywords: Open drains, pathogenic bacteria, antibiotic resistance, wastewater, sediments