Annals of Clinical Microbiology, The official Journal of the Korean Society of Clinical Microbiology

6

Weeks in Review

2

Weeks to Publication
Indexed in KCI, KoreaMed, Synapse, DOAJ
Open Access, Peer Reviewed
pISSN 2288-0585 eISSN 2288-6850

A Korean Nationwide Surveillance Study for Non-Typhoidal Salmonella Isolated in Humans and Food Animals from 2006 to 2008: Extended-Spectrum β-Lactamase, Plasmid-Mediated AmpC β-Lactamase, and Plasmid-Mediated Quinolone Resistance qnr Genes

Original article

Annals of Clinical Microbiology (Ann Clin Microbiol) 2012 March, Volume 15, Issue 1, pages 14-20.

https://doi.org/10.5145/ACM.2012.15.1.14

A Korean Nationwide Surveillance Study for Non-Typhoidal Salmonella Isolated in Humans and Food Animals from 2006 to 2008: Extended-Spectrum β-Lactamase, Plasmid-Mediated AmpC β-Lactamase, and Plasmid-Mediated Quinolone Resistance qnr Genes

Hae-Sun Chung1, Hyukmin Lee2, Yangsoon Lee1, Dongeun Yong1, Seok Hoon Jeong1, Bok-Kwon Lee3, Suk-Chan Jung4, Suk-Kyung Lim4, Kyungwon Le1, Yunsop Chong1
1Department of Laboratory Medicine and Research Institute of Bacterial Resistance, Yonsei University College of Medicine, Seoul, 2Department of Laboratory Medicine, Kwandong University College of Medicine, Goyang, 3Division of Enteric Bacterial Infections, Center for Infectious Diseases, Korea National Institute of Health, Cheongwon, 4Animal, Plant and Fisheries Quartine and Inspection Agency, Anyang, Korea

Abstract

Background: The emergence of non-typhoidal Salmonella (NTS) with decreased susceptibilities to fluoroquinolone, ampicillin, or ceftriaxone has been reported worldwide. However, current surveillance studies of resistance among NTS in Korea are limited. Thus, the antimicrobial susceptibilities; resistance mechanisms such as extended-spectrum β-lactamase (ESBL), plasmid-mediated AmpC β-lactamase (PABL), and plasmid-mediated quinolone resistance (PMQR); and molecular epidemiologic characteristics were investigated in the present study.

Methods: National Institute of Health and National Veterinary Research and Quarantine Service collected NTS strains from 219 clinical and 293 non-clinical specimens from 2006 to 2008. The antimicrobial susceptibilities were determined using the Clinical and Laboratory Standards Institute disk diffusion test. ESBL, PABL, and qnr genotyping were performed using PCR and nucleotide sequencing. Pulsed-field gel electrophoresis was used for the molecular epidemiologic study.

Results: The resistance to ampicillin in clinical and non-clinical NTS was 49% and 18 to 47%, respectively. The resistance rates to trimethoprim-sulfamethoxazole in clinical and non-clinical NTS were 8% and 0 to 41%, respectively. The rates to extended- spectrum cephalosporin were 0 to 1%. One CTX-M- 15-producing isolate and four CMY-2-producing isolates were detected. Notably, PFGE analysis showed four isolates carrying blaCMY-2, including one non-clinical strain had high clonality. Although the rate of ciprofloxacin resistance was very low, two qnrS1-carrying NTS strains were detected in non-clinical specimens.

Conclusion: The resistance rates to ampicillin in both clinical and non-clinical NTS were high, while those to trimethoprim-sulfamethoxazole varied depending on the specimen. NTS strains harboring CTX-M-15- type ESBL or CMY-2-type PABL were detected even though the resistance rates to cephalosporins were very low. Four NTS strains carrying the blaCMY-2- gene implied zoonotic infection. Continuous effort to minimize transfer of resistance genes in NTS is necessary. (Korean J Clin Microbiol 2012;15:14-20)

Keywords

Antimicrobial susceptibility, Extended- spectrum β-lactamase, Korea, Non-typhoidal Salmonella, Plasmid-mediated AmpC β-lactamase, Plasmid-mediated quinolone resistance