Wastewater microbiology: occurrence and prevalence of antibiotic-resistant extended-spectrum <i>β</i>-lactamase-producing Enterobacteriaceae in the district wastewater system

Extended spectrum <i>β</i>-lactamase (ESBL)-producing Enterobacteriaceae, including <i>Klebsiella pneumoniae</i> and <i>Escherichia coli</i>, pose a serious risk to human health because of antibiotic resistance. Wastewater serves as a reservoir for these bacteria, contributing to the evolution and transmission of antibiotic-resistant strains. The research aims to identify ESBL bacterium in wastewater samples from District Kohat. <i>K. pneumoniae</i> and <i>E. coli</i> were confirmed as ESBL-producing bacteria through a comprehensive array of diagnostic procedures, including Gram staining, biochemical analyses, and antibiotic susceptibility testing. Fecal coliform count (FCC) analyses revealed varying microorganism levels. Both <i>E. coli</i> and <i>K. pneumoniae</i> isolates showed ESBL enzyme expression, indicating antibiotic resistance. Resistance patterns included ciprofloxacin, ampicillin, cefotaxime, cefoxitin, and amoxicillin-clavulanic acid for both species. <i>E. coli</i> displayed higher sensitivity for chloramphenicol, trimethoprim- sulfamethoxazole, and gentamicin. Ceftazidime minimum inhibitory concentration results showed <i>E. coli</i>'s higher resistance. The study accentuates the presence of antibiotic-resistant strains, emphasizing the value of effective wastewater treatment. The study provides crucial insights into microbial characteristics, fecal contamination, ESBL production, and antibiotic resistance in <i>E. coli</i> and <i>K. pneumoniae</i> isolates, advocating for monitoring and mitigation strategies.