title: Molecular epidemiology of Pseudomonas aeruginosa clinical isolates from Korea producing β-lactamases with extended-spectrum activity.
abstract: This study was performed to investigate the prevalence and molecular epidemiology of Pseudomonas aeruginosa isolates from Korea that produce enzymes with extended-spectrum (ES) activity to β-lactams. A total of 205 non-duplicate P. aeruginosa clinical isolates were collected from 18 university hospitals in Korea. PCR and sequencing experiments were performed to identify genes encoding β-lactamases. PCR mapping and sequencing of the regions surrounding the β-lactamase genes were performed. Multilocus sequence typing experiments were performed. The most common sequence type (ST) was ST235 (n = 96), and 2 single-locus variants of ST235, ST1015 (n = 1) and ST1162 (n = 1), were also identified. These 3 STs were grouped as a clonal complex (CC), CC235. The remaining 107 isolates were identified as 59 different STs. Isolates belonging to CC235 showed higher rates of non-susceptibility to imipenem (85.4% versus 47.7%) and meropenem (92.7% versus 52.3%) compared to non-CC235 isolates. All the metallo-β-lactamase (MBL)-producing isolates were identified as CC235, except for 1 ST591. Genes encoding OXA-17 and OXA-142 were detected in 1 isolate and 4 isolates of CC235, respectively; while the bla(SHV-12) gene was detected in 4 non-CC235 isolates. Class A and D β-lactamases with ES activity play a role in acquiring ceftazidime resistance in P. aeruginosa in Korea. Production of IMP-6 and VIM-2 MBLs is the main mechanisms in acquiring resistance to ceftazidime and carbapenems in P. aeruginosa isolates in Korea. Clonal spread of P. aeruginosa CC235 may be an important conduit for the dissemination of MBL genes in Korea.
authors.affiliation: Department of Dental Hygiene, Silla University, Busan, Republic of Korea.
authors.forename: Il Kwon
authors.initials: IK
authors.lastname: Bae
authors.affiliation: Department of Laboratory Medicine, MizMedi Hospital, Seoul, Republic of Korea.
authors.forename: Borum
authors.initials: B
authors.lastname: Suh
authors.affiliation: Department of Laboratory Medicine and Research Institute of Bacterial Resistance, Yonsei University College of Medicine, Seoul, Republic of Korea. Electronic address: kscpjsh@yuhs.ac.
authors.forename: Seok Hoon
authors.initials: SH
authors.lastname: Jeong
authors.affiliation: Department of Chemistry, Yonsei University, Seoul, Republic of Korea.
authors.forename: Kang-Kyun
authors.initials: KK
authors.lastname: Wang
authors.affiliation: Department of Chemistry, Yonsei University, Seoul, Republic of Korea.
authors.forename: Yong-Rok
authors.initials: YR
authors.lastname: Kim
authors.affiliation: Department of Laboratory Medicine and Research Institute of Bacterial Resistance, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Dongeun
authors.initials: D
authors.lastname: Yong
authors.affiliation: Department of Laboratory Medicine and Research Institute of Bacterial Resistance, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Kyungwon
authors.initials: K
authors.lastname: Lee
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D024881:Drug Resistance, Bacterial; D005838:Genotype; D006785:Hospitals, University; D006801:Humans; D017720:Molecular Epidemiology; D058885:Multilocus Sequence Typing; D015995:Prevalence; D011552:Pseudomonas Infections / Q000453:epidemiology* / Q000382:microbiology*; D011550:Pseudomonas aeruginosa / Q000145:classification* / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D056910:Republic of Korea / Q000453:epidemiology; D001618:beta-Lactamases / Q000235:genetics*; D047090:beta-Lactams / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D047090:beta-Lactams; D001618:beta-Lactamases
keywords: Clonal complex 235 (CC235); Extended-spectrum oxacillinase; Extended-spectrum β-lactamase; Metallo-β-lactamase