Determination of extended spectrum beta-lactamases, metallo-beta-lactamases and AmpC-beta-lactamases among carbapenem resistant Pseudomonas aeruginosa isolated from burn patients.
BACKGROUND
Pseudomonas aeruginosa is an important cause of morbidity and mortality in patients with burns.


METHODS
A total of 214 nonduplicated burn wound isolates of P. aeruginosa were recovered from burn patients. Identification of carbapenem resistant isolates and their antimicrobial susceptibility pattern was carried out using the phenotypic methods. The presence of genes encoding extended spectrum beta-lactamases (ESBLs) and metallo-beta-lactamases (MBLs) enzymes were determined by PCR. The genetic relationships between carbapenem resistant isolates were determined by Random Amplified Polymorphic DNA (RAPD)-PCR.


RESULTS
Of 214 investigated P. aeruginosa isolates, 100 (46.7%) were carbapenem resistant. All carbapenem resistant P. aeruginosa were resistant to imipenem, meropenem, ertapenem, carbenicillin, aztreonam, gentamicin and ciprofloxacin but susceptible to polymyxin B. Among 100 carbapenem resistant P. aeruginosa isolates, 3%, 65% and 52% were identified as ESBLs, carbapenemase and AmpC overproduction positive isolates respectively. The most prevalent ESBLs and MBLs genes included blaOXA-10 (97%), blaTEM (61%), blaVIM (55%), blaPER (13%), blaIMP (3%) and blaAIM (1%). RAPD analysis yielded 13 distinct profiles among 92 isolates. A dominant RAPD type was designated as A that consisting of 80 isolates.


CONCLUSIONS
This is the first report of Adelaide IMipenmase (AIM) MBLs producing P. aeruginosa from Iran and also of the high prevalence of AmpC overproduction isolates. According to the results of current study, P. aeruginosa isolates producing OXA-10, TEM, VIM, PER and IMP beta-lactamases are frequent and the population structures of these isolates are highly similar.
Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
Davood Kalantar
DK
Neyestanaki
Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
Akbar
A
Mirsalehian
Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
Fereshteh
F
Rezagholizadeh
Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
Fereshteh
F
Jabalameli
Clinical Microbiology Research Center, Ilam University of Medical Sciences, Ilam, Iran.
Morovat
M
Taherikalani
Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. Electronic address: emaneini@tums.ac.ir.
Mohammad
M
Emaneini
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics*; D002056:Burns / Q000150:complications / Q000382:microbiology*; D015780:Carbapenems / Q000494:pharmacology*; D003428:Cross Infection / Q000150:complications / Q000382:microbiology*; D024881:Drug Resistance, Bacterial; D005798:Genes, Bacterial / Q000235:genetics*; D006801:Humans; D008826:Microbial Sensitivity Tests; D016133:Polymerase Chain Reaction; D011552:Pseudomonas Infections / Q000150:complications / Q000382:microbiology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D019105:Random Amplified Polymorphic DNA Technique; D018440:beta-Lactam Resistance / Q000235:genetics*; D001618:beta-Lactamases / Q000235:genetics*
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D015780:Carbapenems; C048795:AmpC beta-lactamases; D001618:beta-Lactamases; C063912:carbapenemase
AmpC; Burn patients; ESBLs; MBLs; Pseudomonas aeruginosa