Molecular Typing of Multidrug-Resistant Pseudomonas aeruginosa Isolates Obtained from Hospitalized Burn Patients by Rep-PCR

Backgrounds: Multidrug-resistant Pseudomonas aeruginosa is known as a major opportunistic pathogen in burn patients with hospital-acquired infections. The aim of this study was to investigate antibiotic resistance and the capability of (GTG) 5-PCR (polymerase chain reaction) assay for molecular typing of P. aeruginosa strains isolated from clinical samples of hospitalized burn patients in southern Iran. Materials Methods: This cross-sectional research was carried out on 70 P. aeruginosa isolates collected from hospitalized burn patients in southern Iran from June 2020 to January 2021. Antimicrobial susceptibility patterns of the isolates were determined using disk diffusion method. Additionally, repetitive extragenic palindromic-PCR (rep-PCR) method was used to examine the genetic similarities among the strains. Findings: Antimicrobial susceptibility patterns revealed that the highest antibiotic resistance was against gentamicin (95.8%), followed by imipenem (94.3%) and piperacillin–tazobactam (92.8%), while colistin was the most effective antimicrobial agent. Rep-PCR typing revealed that 60 P. aeruginosa strains were classified into 49 GTG5 types (G1-G49), which were then grouped into 12 clusters (A-L) and 10 isolates with unique banding patterns according to the 80% cut off point. Conclusion: The present study data indicated a substantial resistance to the studied antimicrobial agents, especially the last-resort antimicrobial agents. In addition, rep-PCR analysis revealed that most of the evaluated strains had partial genetic diversity; therefore, infection control activities should be carried out to decrease the colonization of MDR P. aeruginosa isolates in the hospital setting.