Molecular epidemiology and carbapenem resistance of Pseudomonas aeruginosa isolated from patients with burns

Abstract

Objective: The aim of this study was to investigate the molecular epidemiology and carbapenem resistance mechanisms of Pseudomonas aeruginosa isolated from patients with burns in Azerbaijan, Iran. Method: Pseudomonas aeruginosa was isolated from 38 patients with burns. Disk diffusion and agar dilution methods were used to determine antibiotic susceptibility patterns. The overproduction of AmpC β-lactamase and efflux pumps were detected by phenotypic methods. The presence of carbapenemase-encoding genes was detected by multiplex polymerase chain reaction (PCR). Expression of the OprD gene and MexAB efflux pumps were also evaluated with real-time PCR. Random amplified polymorphic DNA typing (RAPD-PCR) was used for genotyping of carbapenem-resistant Pseudomonas aeruginosa (CRPA). Results: Minimum inhibitory concentration (MIC) assays demonstrated high levels of resistance to all classes of antibiotics except colistin and polymyxin B. The initial screening by carbapenem disks indicated 24 isolates (63.15%) as CRPA. Different mechanisms of carbapenem resistance were observed, including carbapenemase production (8.4%), overexpression of AmpC (25%) and decreased expression of OprD (75%). The overexpression of MexAB efflux pumps was detected in 19 (79.1%) isolates by phenotypic assay or real-time PCR. The resistance to carbapenem was multifactorial in most cases (58.3%). The RAPD genotyping revealed different patterns with nine clusters. Conclusion: According to our results, the prevalence of CRPA is at an alarming level. Our results did not demonstrate an epidemic clone. The most common mechanism of carbapenem resistance was decreased expression of OprD. Therefore, we suggest a reconsideration in the management of CRPA infections of patients in our burn care hospital in Azerbaijan, Iran.

RAPD-PCR-Based Fingerprinting Method as a Tool for Epidemiological Analysis of Trueperella pyogenes Infections

“…To the best of our knowledge, this is the first work that describes the development and optimization of a RAPD-PCR procedure intended as a molecular tool for typing T. pyogenes strains. This technique has been demonstrated previously as a useful tool for molecular differentiation of a wide range of pathogens [ 15 , 16 , 17 , 18 , 19 , 20 ].…”

Pyoverdine as an Important Virulence Factor in Pseudomonas aeruginosa Antibiotic Resistance

“…Therefore, the virulence factor or determinant is a microbial component that favors growth or survival during infection; iron being a determining factor of intracellular survival for the growth of most bacteria and especially pathogens, such as P. aeruginosa, an opportunistic human pathogen [26,27].…”

Antimicrobial and antibiofilm activities of meropenem loaded-mesoporous silica nanoparticles against carbapenem-resistant Pseudomonas aeruginosa

“…At least two-fold decreased of the MIC in the presence of PAbN was considered as an overexpression efflux pumps. 34 The carbapenemase encoding genes were identified by the multiplex PCR according to the previous study. 35 The expression level of oprD and mexB were detected by the real-time quantitative reverse transcription PCR (RT-PCR) and specific primers for rpsL, oprD and mexB genes as recommended previously.…”