Antibiotic resistance of Pseudomonas aeruginosa and Escherichia coli isolated from untreated water of hospitals in Baghdad city

Abstract

Abstract: Antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in untreated hospital wastewater form a major environmental and public health concern. The aim of this study was to investigate the antibiotic resistance patterns of Pseudomonas aeruginosa and Escherichia coli isolated from untreated wastewater of hospitals in Baghdad. These bacteria were selected to represent the most prevalent gram-negative bacteria found in hospital wastewater, and they have the potential to generate resistance and spread resistance genes to antibiotics. A total of 150 samples were collected during January 2024- May 2024. VITEK 2 system correctly identified and 16S rRNA gene confirmed 10 (6.7%) and 12 (8%) isolates of P. aeruginosa and E. coli respectively. All (100%) P. aeruginosa isolates and 10 (83%) of E. coli isolates were positive for Bla_CTX-M gene while all isolates were negative for other genes (bla_SHV, bla_VIM and Bla_TEM). P. aeruginosa and E. coli isolates were found to show the highest sensitivity to Colistin and the highest resistance to Ticarcillin, Piperacillin, Imipenem and Meropenem. The findings of this study indicate that wastewater of hospitals requires additional treatment to reduce discharged ARB and ARGs in the receiving water bodies. As a result, the efficiency of the quality should be continuously monitored and assessed.