Phenotypic Susceptibility, β-Lactamase Gene Detection, and RAPD Typing of Clinical Pseudomonas aeruginosa Isolates from Najaf Hospitals, Iraq

Pseudomonas aeruginosa infections present significant treatment challenges due to their inherent resistance to numerous antibiotics and their capacity to develop further resistance mechanisms. This study aimed to investigate antimicrobial susceptibility profiles, detect major β-lactamase genes (blaIMP, blaSHV, blaTEM, and blaNDM), and assess genetic relatedness using RAPD typing among P. aeruginosa clinical isolates from Najaf hospitals. Materials: Twenty clinical isolates of P. aeruginosa were obtained from hospitals in Najaf City. . The identification of isolates in the laboratory was conducted using standard biochemical tests. All isolates were maintained in trypticase soy broth with the addition of 20% glycerol at –70°C. P. aeruginosa ATCC 27853 served as the standard for quality control measures. Then cultured for antibiotic sensitivity testing, there after PCR to detect the blaIMP, blaSHV, blaTEM and blaNDM genes. Results: The investigation of the antibiotics susceptibility in recent study revealed the following resistance profile among P. aeruginosa isolates: piperacillin (10%), ceftazidime (95%), ciprofloxacin (95%), tazobactam (40%), gentamicin (10%), avibactam (25%), cefepime (95%), meropenem (20%), colistin (95%), and imipenem (55%). PCR analysis revealed the presence of blaTEM in all isolates, while blaIMP, blaSHV, and blaNDM were not detected. No insertional mutation was observed in the OprD gene. In this study, the blaIMP , blaSIHV, and blaNDM genes were not detected among the isolates, and no mutation was observed regarding the presence of an insertion element in the OprD gene