Clonal spread of Klebsiella pneumoniae producing CMY-2 AmpC-type β-lactamase in surgical intensive care units

Hsin Chun Lee, Jing Jou Yan, Jiunn Jong Wu, Chai Ming Chang, Chi Jung Wu, Nan Yao Lee, Po Ling Chen, Ching Chi Lee, Wen Chien Ko

Research output: Contribution to journalArticlepeer-review


Background and purpose: CMY-2, an AmpC-type β-lactamase, has become more prevalent in Klebsiella pneumoniae isolates at the National Cheng Kung University Hospital, Tainan, Taiwan. This retrospective study investigated the epidemiological characteristics of CMY-2-producing strains of K. pneumoniae. Methods: Molecular experiments were performed to describe the blaCMY-2 gene carriage rate and the trend of K. pneumoniae isolates with resistance to cefoxitin between January 2001 and June 2003. The epidemiological correlation between patients with blaCMY-2-positive K. pneumoniae was further analyzed and compared by chart review and pulsed-field gel electrophoresis (PFGE). Results: Of 285 cefoxitin-resistant K. pneumoniae isolates, 69 (24.2%) carried a blaCMY-2 sequence. The first blaCMY-2-positive isolate of each patient was genotyped by PFGE; 49 (89.1%) of 55 were genetically related. Forty five isolates (91.8%) were noted between January and September 2002. Eighteen isolates were from patients in 2 surgical intensive care units (SICUs), and 23 were from patients with prior SICU stays. Compared with patients with non-epidemic CMY-2-producing isolates, patients with the epidemic clone had a shorter duration of hospital stay (p = 0.007) and SICU stay (p = 0.01) before isolation. Recent surgery was independently associated with acquisition of epidemic CMY-2-producing K. pneumoniae. Conclusions: An unrecognized clonal spread of K. pneumoniae producing CMY-2 AmpC-type β-lactamase in SICUs was found. Cross-transmission of the epidemic clone, suggested by a shorter hospital stay before isolation of the bacterium and the association with recent surgery, highlights the importance of surveillance to recognize an epidemic and initiate control measures.

Original languageEnglish
Pages (from-to)479-487
Number of pages9
JournalJournal of Microbiology, Immunology and Infection
Issue number6
Publication statusPublished - 2009 Dec

All Science Journal Classification (ASJC) codes

  • Immunology and Allergy
  • Immunology and Microbiology(all)
  • Microbiology (medical)
  • Infectious Diseases

Fingerprint Dive into the research topics of 'Clonal spread of Klebsiella pneumoniae producing CMY-2 AmpC-type β-lactamase in surgical intensive care units'. Together they form a unique fingerprint.

Cite this