Infection and Drug Resistance (Jul 2019)

Resistance mechanisms and molecular epidemiology of carbapenem-nonsusceptible Escherichia coli in Taiwan, 2012-2015

  • Chang YT,
  • Siu LK,
  • Wang JT,
  • Wu TL,
  • Chen YH,
  • Chuang YC,
  • Lin JC,
  • Lu PL

Journal volume & issue
Vol. Volume 12
pp. 2113 – 2123

Abstract

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Ya-Ting Chang,1 L Kristopher Siu,2 Jann-Tay Wang,3 Tsu-Lan Wu,4 Yu-Hui Chen,5,6 Yin-Ching Chuang,7,8 Jung-Chung Lin,9 Po-Liang Lu1,101Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; 2National Institutes of Infectious Diseases and Vaccinology, National Health Research Institutes, Miaoli, Taiwan; 3Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan; 4Department of Clinical Pathology, Linkou Chang Gung Memorial Hospital, Taoyuan, Taiwan; 5Infection Control Center, Chi Mei Medical Center, Tainan, Taiwan; 6Department of Nursing, College of Medicine and Life Science, Chung Hwa University of Medical Technology, Tainan, Taiwan; 7Department of Internal Medicine and Medical Research, Chi Mei Medical Center, Tainan, Taiwan; 8Department of Internal Medicine, Chi Mei Medical Center, Tainan, Taiwan; 9Division of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan; 10College of Medicine, Kaohsiung Medical University, Kaohsiung, TaiwanPurpose: This study aimed to investigate the resistance mechanisms and molecular epidemiology of carbapenem-nonsusceptible Escherichia coli (CnsEC) in Taiwan.Patients and methods: From 2012 to 2015, 237 E. coli isolates with minimum inhibitory concentrations of imipenem or meropenem >1 μg/mL were collected in a nationwide surveillance and subjected to polymerase chain reaction (PCR) for carbapenemase, AmpC-type β-lactamase, and extended spectrum β-lactamase (ESBL) genes. We evaluated outer membrane proteins (OmpF and OmpC) loss and conducted multilocus sequence typing and pulsed-field gel electrophoresis (PFGE). Isolates that were resistant to all carbapenems were designated as pan-carbapenem-resistant E. coli (pCREC) in this study.Results: The predominant resistance mechanism of CnsEC in Taiwan was the CMY-2 β-lactamase in combination with OmpF and OmpC loss. Sequence type 131 was the most prevalent type (29.2%). Among 237 CnsEC isolates, 106 (44.7%) isolates were pCREC and 18 (7.59%) produced carbapenemase. The prevalence of carbapenemases increased from 6% in 2012 to 11.36% in 2015. Various carbapenemases including KPC-2, IMP-8, NDM-1, NDM-5, VIM-1, OXA-48, and OXA-181 were identified, with NDM-1 being the most common (38.9%) carbapenemase. Comparison between pCREC and non-pCREC among the non-carbapenemase-producing CnsEC isolates revealed SHV, CMY, co-carriage of SHV and CTX-M and concurrent loss of both OmpF and OmpC were more commonly detected in the pCREC group. PFGE revealed no nationwide clonal spread of carbapenemase-producing E. coli.Conclusion: NDM-1 was the most common carbapenemase and combination of CMY-2 and concurrent OmpF and OmpC porin loss was the most prevalent resistance mechanism in CnsEC in Taiwan.Keywords: multidrug resistance, carbapenemase, Enterobacteriaceae, epidemiology

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