Domestic wastewater is considered a favorable environment for the survival of broad arrays of microorganisms. The current study aimed to characterize the bacteria isolated from two domestic wastewater treatment plants in Jazan, KSA. Morphological and biochemical tests were used to identify the bacterial isolates. Moreover, the antibiotic susceptibility pattern of the bacteria isolates was studied using disc diffusion method. The enteric Gram-negative Enterobacteriaceae were identified as Citrobacter freundii, Pantoea sp., Serratia liquefaciens, Serratia odorifera, Proteus vulgaris, Rahnella aquatilis, Enterobacter sp., Escherichia coli, and Enterobacter cloacae. Simultaneously, non-enteric Gram-negative bacilli were identified as Sphingomonas paucimobilis, Pseudomonas putida, Pseudomonas aeruginosa, Aeromonas sobria, Chryseomonas luteola, and Pasteurella aerogenes. Also, the Gram-positive isolates were identified as Staphylococcus xylosus, Kocuria kristinae and Staphylococcus epidermidis. At the same time, a high level of resistance against Ampicillin/Sulbactam (94.5%) was observed while the recorded percentage of resistance against trimethoprime/sulphamethoxoazole, ticarcillin, imipenen, piperacillin, colistin, cefoxitin and cefepime were 67%, 62%, 22.2%, 33.3%, 22.2%, 83.3% and 38.9% respectively. This study highlighted the existence of multiple antibiotic resistant strains in the tested sewage wastewater that could be attributed to the disproportionate use of antibiotics for human and animal diseases.
Key words: Bacteria, Sewage, Biochemical characteristics, Identification, Antibiotic resistance
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