Prevalence of Ambler class A and D β-lactamases among clinical isolates of Pseudomonas aeruginosa in Korea

• Published in: Journal of antimicrobial chemotherapy 2005-07, Vol.56 (1), p.122-127
• Main Authors: Lee, Seungok, Park, Yeon-Joon, Kim, Myungshin, Lee, Hae Kyung, Han, Kyungja, Kang, Chang Suk, Kang, Moon Won
• Format: Article
• Language: English
• Subjects: Antibiotics. Antiinfectious agents. Antiparasitic agents; beta-Lactamases - classification; beta-Lactamases - genetics; Biological and medical sciences; Drug Resistance, Bacterial; ESBLs; extended-spectrum β-lactamases; Humans; Medical sciences; Microbial Sensitivity Tests; OXA-17; P. aeruginosa; Pharmacology. Drug treatments; Pseudomonas aeruginosa; Pseudomonas aeruginosa - drug effects; Pseudomonas aeruginosa - enzymology
• ISSN: 0305-7453; 1460-2091
• DOI: 10.1093/jac/dki160

Objectives: Recently, resistance to extended-spectrum cephalosporins due to acquired β-lactamases has been reported in Pseudomonas aeruginosa. The aim of this study was to investigate the prevalence of Ambler class A and D β-lactamases and their extended-spectrum derivatives and antimicrobial susceptibilities of P. aeruginosa isolated from various parts of Korea. Methods: A total of 252 consecutive, non-duplicate isolates of P. aeruginosa were studied for the presence of class A or D β-lactamase. Antibiotic susceptibility tests and PCR amplification of genes encoding class A (blaPSE-1, blaPER-1, blaVEB-1, blaTEM, blaSHV, blaCTX-M and blaGES-1) and class D β-lactamases (blaOXA-groupI, blaOXA-groupII and blaOXA-groupIII) were performed. For PCR-positive isolates, isoelectric focusing (IEF) analysis, sequencing and pulsed-field gel electrophoresis (PFGE) were performed. Results: In 64 (25.4%) isolates, structural genes for PSE-1 (6.3%), OXA-10 (13.1%), OXA-4 (4.3%), OXA-30 (2.0%), OXA-2 (2.3%) and OXA-17 (0.4%) were found; their distribution varied between provinces. None harboured blaPER-1, blaVEB-1, blaTEM, blaSHV, blaCTX-M and blaGES-1. The cross-class resistance rates to other antibiotics was significantly higher in class A and D β-lactamase producers than in non-producers (P < 0.001 for aminoglycosides, ciprofloxacin and meropenem). Conclusions: OXA-type β-lactamases are widespread, but their extended-spectrum derivatives are rare among P. aeruginosa in Korea. To our knowledge, this is the first report of OXA-17, an extended-spectrum derivative of OXA-10, outside the Middle East. In addition, combined resistance to ticarcillin and aminoglycosides was a useful indicator for P. aeruginosa producing PSE- or OXA-type β-lactamases in this study.