Characterization of IncF plasmids carrying the blaCTX-M-14 gene in clinical isolates of Escherichia coli from Korea

• Published in: Journal of antimicrobial chemotherapy 2011-06, Vol.66 (6), p.1263-1268
• Main Authors: KIM, Juwon, IL KWON BAE, SEOK HOON JEONG, CHANG, Chulhun L, CHAE HOON LEE, LEE, Kyungwon
• Format: Article
• Language: English
• Subjects: Anti-Bacterial Agents - pharmacology; Antibiotics. Antiinfectious agents. Antiparasitic agents; Bacterial Typing Techniques; beta-Lactam Resistance; beta-Lactamases - genetics; Biological and medical sciences; Cefotaxime - pharmacology; Ceftazidime - pharmacology; Deoxyribonucleases, Type II Site-Specific - metabolism; DNA, Bacterial - chemistry; DNA, Bacterial - genetics; DNA, Bacterial - metabolism; Escherichia coli - classification; Escherichia coli - enzymology; Escherichia coli - genetics; Escherichia coli - isolation & purification; Escherichia coli Infections - epidemiology; Escherichia coli Infections - microbiology; Gene Transfer, Horizontal; Korea - epidemiology; Medical sciences; Molecular Epidemiology; Molecular Sequence Data; Molecular Typing; Pharmacology. Drug treatments; Plasmids; Polymorphism, Restriction Fragment Length; Sequence Analysis, DNA
• ISSN: 0305-7453; 1460-2091
• DOI: 10.1093/jac/dkr106

The purpose of this study was to investigate the molecular epidemiology of CTX-M-14-producing Escherichia coli clinical isolates from Korea. A total of 138 non-duplicate E. coli clinical isolates showing reduced susceptibility or resistance to ceftazidime and/or cefotaxime were included in the study. Resistance genes, genetic environment, R plasmid size and replicon type, sequence type (ST) and XbaI-macrorestriction patterns were determined. Among 138 isolates, 35 were found to carry the bla(CTX-M-14) gene. The ISEcp1 element was identified in the upstream region of the bla(CTX-M-14) gene in 32 isolates. The bla(CTX-M-14) gene was located on an IncF plasmid in 21 isolates, on an IncA/C plasmid in 1 isolate, on the chromosome in 8 isolates and on both the chromosome and an IncF plasmid in 5 isolates. The most prevalent ST was ST405 (n = 8), followed by ST354 (n = 4), ST38 (n = 3), ST69 (n = 3) and the intercontinental ST, ST131 (n = 3). PFGE and multilocus sequence typing experiments demonstrated no major clonal relationship among the CTX-M-14-producing isolates. The bla(CTX-M-14) gene was probably mobilized by IncF plasmids, which can readily spread in E. coli, causing horizontal dissemination of the resistance gene in Korea.