Evaluation of β-lactamases and Molecular Typing of Pseudomonas aeruginosa Clinical Strains Isolated from Hospitalized Children in Tehran

Background: The opportunistic human pathogen, Pseudomonas aeruginosa, is a critical cause of nosocomial infection with high morbidity and mortality rate. Eradication P. aeruginosa has been troublesome due to its capacity develop strong multidrug resistance (MDR). Objectives: purposes this study were define the pattern antimicrobial sensitivity, typing, prevalence metallo-β-lactamase (MBL) detect oprD, blaCTX-M, blaSHV, blaTEM, blaIMP, blaNDM, blaVIM among clinical isolates collected from Tehran hospitals. Methods: Clinical hospitalized children in selected hospitals March 2019 February 2020. susceptibility test (AST) was performed by Kirby-Bauer disk diffusion method. Composed disc tests screen MBL production. MBLs extended-spectrum β-lactamases (ESBL) encoding genes amplified polymerase chain reaction (PCR). Amplification oprD gene for carbapenem-resistant aeruginosa. Random polymorphic DNA (RAPD-PCR) Fingerprinting used genotyping isolates. Results: A total 80 collected. Isolates resistant cefepime 35%, ceftazidime 20%, ciprofloxacin 22%, tazobactam 16%. Out isolates, 16 carbapenems-resistant. Gentamicin, tobramycin, amikacin had highest susceptibilities 85%,90%, 90%, respectively. OprD, blaTEM detected 80(100%), 36(45%),22 (27.5%), 17 (21.25%), 1 (1.25%) blaIMP In study, not no mutation observed regarding presence an insertion element OprD gene. divided into 13 14 common single types, Conclusions: showed rate β- lactamases production, carbapenem-resistant, which can be related different mechanisms, alarming. On other hand, results demonstrated that there beta-lactam antibiotic clonal spread hospital population. This shows necessity molecular surveillance tracking beta-lactamase-producing strains.