title: Emergence of colistin resistance in Pseudomonas aeruginosa ST235 clone in South Korea.
abstract: In this study, the prevalence and characteristics of metallo-β-lactamase (MBL)-producing Pseudomonas aeruginosa isolates in South Korea were investigated. Among 215 P. aeruginosa isolates collected from eight hospitals, 77 (35.8%) and 72 (33.5%) were resistant to imipenem and meropenem, respectively. Of the 77 imipenem-resistant isolates, MBL genes were identified in 34 isolates (blaIMP-6in 33 isolates and blaVIM-2in 1 isolate). All of the MBL-producing isolates belonged to a globally prevailing genotype, sequence type 235 (ST235), and all of the IMP-6-producing isolates showed a deletion of nucleotide 209 of the porin gene oprD. Of the 33 IMP-6-producing ST235 isolates, 9 were resistant to colistin and exhibited resistance to all antimicrobial agents included in this study. PhoPQ and PmrAB amino acid alterations were not identical in the colistin-resistant isolates, indicating independent emergence of colistin resistance in this high-risk clone. Carbapenem resistance in P. aeruginosa has increased in South Korea owing to the dissemination of IMP-6-producing ST235 isolates, which showed high-level resistance to meropenem. Emergence of colistin resistance in the disseminated resistant clone would be a significant threat because few alternatives are left for the treatment of systemic infections.
authors.affiliation: Division of Infectious Diseases, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, Republic of Korea.
authors.forename: Yu Mi
authors.initials: YM
authors.lastname: Wi
authors.affiliation: Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea.
authors.forename: Ji-Young
authors.initials: JY
authors.lastname: Choi
authors.affiliation: Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea.
authors.forename: Ji-Young
authors.initials: JY
authors.lastname: Lee
authors.affiliation: Division of Infectious Diseases, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Cheol-In
authors.initials: CI
authors.lastname: Kang
authors.affiliation: Division of Infectious Diseases, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea; Asia-Pacific Research Foundation for Infectious Diseases, Seoul, Republic of Korea.
authors.forename: Doo Ryeon
authors.initials: DR
authors.lastname: Chung
authors.affiliation: Division of Infectious Diseases, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Kyong Ran
authors.initials: KR
authors.lastname: Peck
authors.affiliation: Division of Infectious Diseases, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea; Asia-Pacific Research Foundation for Infectious Diseases, Seoul, Republic of Korea.
authors.forename: Jae-Hoon
authors.initials: JH
authors.lastname: Song
authors.affiliation: Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea; Asia-Pacific Research Foundation for Infectious Diseases, Seoul, Republic of Korea. Electronic address: ksko@skku.edu.
authors.forename: Kwan Soo
authors.initials: KS
authors.lastname: Ko
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics; D003091:Colistin / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial; D005838:Genotype; D006801:Humans; D058889:Molecular Typing; D015995:Prevalence; D011446:Prospective Studies; D011552:Pseudomonas Infections / Q000453:epidemiology / Q000382:microbiology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics / Q000302:isolation & purification; D056910:Republic of Korea / Q000453:epidemiology; D001618:beta-Lactamases / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D001618:beta-Lactamases; D003091:Colistin
keywords: Colistin resistance; IMP-6; MBL; Metallo-β-lactamase; ST235