Antibiotic Susceptibility Patterns and Molecular Epidemiology of Metallo-β-Lactamase Producing Pseudomonas Aeruginosa Strains Isolated From Burn Patients

Abstract

Background:Failure in the treatment of burn patients infected with Pseudomonas aeruginosa could happen as a result of the acquisition of antibiotic resistance, including carbapenems.Objectives:The aim of the present study was to investigate the phenotypic and genotypic characteristics of the Pseudomonas aeruginosa strains, isolated from burn patients.Patients and Methods:During a 12 month period, in this cross-sectional study, two hundred seventy strains of Pseudomonas aeruginosa were isolated from the burn patients in Ghotbeddin Burn Hospital, Shiraz, Iran. Screening for the carbapenem resistance in the isolates was carried out by the E test method. Sensitivity patterns of metallo-β-lactamase (MβLs) producing strains of pseudomonas to eleven antibiotics were determined by the mentioned method. The epidemiological associations of these strains were determined by Pulsed-field gel electrophoresis (PFGE).Results:Of the 270 strains, 60 (22.2%) were resistant to imipenem and meropenem, classified as MβLs producing. MβLs producing strains of pseudomonas were completely resistant to five tested antibiotics while their sensitivities to the three most effective antibiotics including ceftazidime, amikacin and ciprofloxacin were 23.4%, 6.7 % and 1.7%, respectively. In PFGE, 37 patterns from the genome of Pseudomonas aeruginosa were observed. Majority of the strains (43; 71.6%) exhibited more than 80% similarity, based on the drawn dendrogram.Conclusions:According to the results, none of the tested antibiotics is safe to prescribe. As PFGE revealed, a limited number of Pseudomonas aeruginosa types are predominant in the hospitals which infect the burn patients.

Investigation of the Chemical Composition and Different Effects of a Rumex dentatus Methanol Extract Against Drug Resistant Pseudomonas aeruginosa Isolates

“…A previous study addressed examined Iranian isolates of P. aeruginosa that were resistant to penicillin (100%), tetracycline (90.19%), streptomycin (64.70%), and erythromycin (43.13%) (3). Another study showed a 22.2% resistance of P. aeruginosa to imipenem and meropenem (4). The appearance of pan-drug resistant strains of this pathogen render it truly untreatable with current antibiotics and has spurred efforts to develop antibacterial agents active against them (4,5).…”

“…Another study showed a 22.2% resistance of P. aeruginosa to imipenem and meropenem (4). The appearance of pan-drug resistant strains of this pathogen render it truly untreatable with current antibiotics and has spurred efforts to develop antibacterial agents active against them (4,5). An alternative and safe approach to treatment is to use medicinal plants (6).…”

Morphological and Bactericidal Effects of Amikacin, Meropenem and Imipenem on Pseudomonas aeruginosa

“…Sigma factor encoded by rpoS gene, is a positive regulator of many genes including those involved in the synthesis of exotoxin and antibiotic tolerance. Studies showed that cells with mutations in the rpoS gene have less ability to survive than those without mutation in rpoS ( 14 , 15 ). Due to increased mortality rate in burned patients infected with P. aeruginosa , we decided to study in vitro morphological effect of routine antibiotics used for patients' treatment in our hospital (amikacin, meropenem and imipenem) on P. aeruginosa .…”

Characterization of Toxin-Antitoxin (TA) Systems in Pseudomonas aeruginosa Clinical Isolates in Iran

“…Multidrug-resistant P. aeruginosa (MRPA) is currently one of the major concerns in health care systems, as it causes nosocomial infections in hospitals throughout the world, including in Iran. Japoni et al have reported that 22% of metallo-β-lactamase-producing P. aeruginosa isolates were completely resistant to imipenem, meropenem, piperacillin/tazobactam, ampicillin, and aztreonam ( 16 ), while Moniri and Tavajjohi detected a 30% rate of multidrug-resistant isolates in their study ( 17 ). Therefore, new strategies are needed to solve the problem of MRPA.…”