Ann Lab Med.  2013 Sep;33(5):353-355. 10.3343/alm.2013.33.5.353.

An Increase in the Clinical Isolation of Acquired AmpC beta-Lactamase-Producing Klebsiella pneumoniae in Korea from 2007 to 2010

• Park MJ
• Kim TK
• Song W
• Kim JS
• Kim HS
• Lee J

• KMID: 1781341
• DOI: http://doi.org/10.3343/alm.2013.33.5.353

Abstract

We investigated the occurrence and genetic basis of AmpC beta-lactamase (AmpC)-mediated antibiotic resistance, by examining Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis isolates at a university hospital, from 2007 to 2010. The ampC genes were detected by multiplex AmpC PCR, and AmpC-positive strains were subjected to DNA sequencing. Extended-spectrum beta-lactamase (ESBL) production was assessed using the ESBL disk test based on the utilization of boronic acid. Carbapenem-resistant isolates were further investigated by the modified Hodge test, a carbapenemase inhibition test and SDS-PAGE experiments. AmpC expression was detected in 1.6% of E. coli (39 DHA-1, 45 CMY-2, and 1 CMY-1) isolates, 7.2% of K. pneumoniae (39 DHA-1, 45 CMY-2, and 1 CMY-1) isolates, and 2.5% of P. mirabilis (8 CMY-2 and 1 CMY-1) isolates. Of the 198 acquired AmpC producers, 58 isolates (29.3%) also produced an ESBL enzyme. Among the acquired AmpC-producing K. pneumoniae isolates, the minimum inhibitory concentration (MIC) MIC50/MIC90 values for cefoxitin, cefotaxime, cefepime, imipenem, and meropenem were >32/>32, 16/>32, 1/16, 0.25/0.5, and <0.125/0.125 microg/mL, respectively. The MIC values for carbapenem were > or =2 microg/mL for 2 K. pneumoniae isolates, both of which carried the blaDHA-1 gene with a loss of OmpK36 expression, but were negative for carbapenemase production. The acquisition of AmpC-mediated resistance in K. pneumoniae isolates increased, as did the proportion of AmpC and ESBL co-producers among the hospital isolates. The accurate identification of isolates producing AmpCs and ESBLs may aid in infection control and will assist physicians in selecting an appropriate antibiotic regimen.

Keyword

Klebsiella pneumoniae; AmpC beta-lactamases; DHA-1; CMY-2

MeSH Terms

Anti-Bacterial Agents/pharmacology
Bacterial Proteins/*genetics
DNA, Bacterial/genetics
Enterobacteriaceae Infections/*epidemiology/*microbiology
Escherichia coli/drug effects/enzymology/isolation & purification
Hospitals, University/statistics & numerical data
Humans
Klebsiella pneumoniae/drug effects/enzymology/isolation & purification/*physiology
Microbial Sensitivity Tests
Multiplex Polymerase Chain Reaction
Proteus mirabilis/drug effects/enzymology/isolation & purification
Republic of Korea/epidemiology
beta-Lactamases/*genetics
Anti-Bacterial Agents
Bacterial Proteins
DNA, Bacterial
beta-Lactamases

Reference

1. Philippon A, Arlet G, Jacoby GA. Plasmid-determined AmpC β-lactamases. Antimicrob Agents Chemother. 2002; 46:1–11. PMID: 11751104.

2. Bauernfeind A, Chong Y, Schweighart S. Extended broad spectrum β-lactamase in Klebsiella pneumoniae including resistance to cephamycins. Infection. 1989; 17:316–321. PMID: 2689349.

3. Song W, Kim JS, Kim HS, Yong D, Jeong SH, Park MJ, et al. Increasing trend in the prevalence of plasmid-mediated AmpC β-lactamases in Enterobacteriaceae lacking chromosomal ampC gene at a Korean university hospital from 2002 to 2004. Diagn Microbiol Infect Dis. 2006; 55:219–224. PMID: 16545935.

4. Pérez-Pérez FJ, Hanson ND. Detection of plasmid-mediated AmpC β-lactamase genes in clinical isolates by using multiplex PCR. J Clin Microbiol. 2002; 40:2153–2162. PMID: 12037080.

5. Clinical and Laboratory Standards Institute. Performance standards for antimicrobial susceptibility testing. Nineteenth informational supplement, M100-S21. Wayne, PA: CLSI;2011.

6. Song W, Jeong SH, Kim HS, Kim HS, Shin DH, Roh KH, et al. Use of boronic acid disk methods to detect the combined expression of plasmid-mediated AmpC β-lactamases and extended-spectrum β-lactamases in clinical isolates of Klebsiella spp., Salmonella spp., and Proteus mirabilis. Diagn Microbiol Infect Dis. 2007; 57:315–318. PMID: 17174510.

7. Anderson KF, Lonsway DR, Rasheed JK, Biddle J, Jensen B, McDougal LK, et al. Evaluation of methods to identify the Klebsiella pneumoniae carbapenemase in Enterobacteriaceae. J Clin Microbiol. 2007; 45:2723–2725. PMID: 17581941.

8. Giske CG, Gezelius L, Samuelsen Ø, Warner M, Sundsfjord A, Woodford N. A sensitive and specific phenotypic assay for detection of metallo-β-lactamases and KPC in Klebsiella pneumoniae with the use of meropenem disks supplemented with aminophenylboronic acid, dipicolinic acid and cloxacillin. Clin Microbiol Infect. 2011; 17:552–556. PMID: 20597925.

9. Kaczmarek FM, Dib-Hajj F, Shang W, Gootz TD. High-level carbapenem resistance in a Klebsiella pneumoniae clinical isolate is due to the combination of bla_ACT-1 β-lactamase production, porin OmpK35/36 insertional inactivation, and down-regulation of the phosphate transport porin PhoE. Antimicrob Agents Chemother. 2006; 50:3396–3406. PMID: 17005822.

10. Song W, Kim JS, Kim MN, Kim EC, Park YJ, Yong D, et al. Occurrence and genotypic distributions of plasmid-mediated AmpC β-lactamase-producing Escherichia coli and Klebsiella pneumoniae in Korea. Korean J Lab Med. 2002; 22:410–416.

11. Song W, Suh B, Choi JY, Jeong SH, Jeon EH, Lee YK, et al. In vivo selection of carbapenem-resistant Klebsiellae pneumonia by OmpK36 loss during meropenem treatment. Diagn Microbiol Infect Dis. 2009; 65:447–449. PMID: 19766430.

12. Shin SY, Bae IK, Kim J, Jeong SH, Yong D, Kim JM, et al. Resistance to carbapenems in sequence type 11 Klebsiella pneumoniae is related to DHA-1 and loss of OmpK35 and/or OmpK36. J Med Microbiol. 2012; 61:239–245. PMID: 21940650.