Use of Boronic Acid Disks for the Detection of Extended-spectrum beta-lactamase and AmpC beta-lactamase in Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca and Proteus mirabilis.
10.5145/KJCM.2009.12.1.24
- Author:
Soon Deok PARK
1
;
Young UH
;
In Ho JANG
;
Ohgun KWON
;
Kap Jun YOON
;
Hyo Youl KIM
Author Information
1. Department of Laboratory Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea. mizpark66@empal.com
- Publication Type:Original Article
- Keywords:
Extended-spectrum beta-lactamase;
Plasmid- mediated AmpC beta-lactamase;
Boronic acid;
Coproducers
- MeSH:
Bacterial Proteins;
beta-Lactamases;
Boron;
Cefoxitin;
Escherichia;
Escherichia coli;
Humans;
Klebsiella;
Klebsiella oxytoca;
Klebsiella pneumoniae;
Masks;
Mirabilis;
Penicillinase;
Pneumonia;
Proteus;
Proteus mirabilis
- From:Korean Journal of Clinical Microbiology
2009;12(1):24-29
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
BACKGROUND: Accurate detection of organisms producing extended-spectrum beta-lactamase (ESBL) and AmpC beta-lactamase is very important for treatment of patients. However, unlike the ESBL confirmatory test, there are no guidelines for detection of organisms producing AmpC beta-lactamase. We evaluated a detection method using boronic acid (BA) for ESBL and AmpC beta-lactamase. METHODS: Clinical isolates of Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, and Proteus mirabilis showing intermediate resistance or resistance to cefoxitin (FOX) or positive for ESBL were tested. A > or =5 mm increase in zone diameter of ceftazidime/clavulanic acid/BA (CAZ/CA/BA) and/or cefotaxime/clavulanic acid/BA (CTX/CA/BA) versus CAZ/BA and/or CTX /BA was considered positive for ESBL. Likewise, a > or =5 mm increase in zone diameter of FOX/BA and/or cefotetan/BA (CTT/BA) versus FOX and/or CTT alone was considered positive for AmpC beta-lactamase. RESULTS: Among 622 clinical isolates, ESBL positive rates by the CLSI ESBL confirmatory test or by the BA method were 18.1% or 18.4% for E. coli, 38.3% or 40.4% for K. pneumoniae, 8.7% or 8.7% for K. oxytoca, and 14.8% or 14.8% for P. mirabilis, respectively. AmpC beta-lactamase positive rates using the BA method were 3.7% for E. coli, 33.3% for K. pneumoniae, 0% for K. oxytoca, and 7.4% for P. mirabilis. The detection rates of coproducing ESBL and AmpC beta-lactamase were 2.4% in E. coli 27.1% in K. pneumoniae, and 3.7% in P. mirabilis. CONCLUSION: The ESBL confirmatory method using BA was found to enhance the detection of ESBLs, even when potentially masked by AmpC beta-lactamase.
