Antimicrobial activities of ceftazidime-avibactam, ceftolozane-tazobactam, and other agents against escherichia coli, klebsiella pneumoniae, and pseudomonas aeruginosa isolated from intensive care units in Taiwan: Results from the surveillance of multicenter antimicrobial resistance in Taiwan in 2016

Chun Hsing Liao, Na Yao Lee, Hung Jen Tang, Susan Shin Jung Lee, Chin Fu Lin, Po Liang Lu, Jiunn Jong Wu, Wen Chien Ko, Wen Sen Lee, Po Ren Hsueh

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4 Citations (Scopus)


Objective: The aim of this study was to investigate the in vitro antimicrobial susceptibilities of clinically important Gram-negative bacteria from seven intensive care units in Taiwan in 2016. Materials and methods: In total, 300 non-duplicate isolates of Escherichia coli (n=100), Klebsiella pneumoniae (n=100), and Pseudomonas aeruginosa (n=100) collected from 300 patients were studied. The minimum inhibitory concentrations (MICs) of these isolates to antimicrobial agents were determined using the broth microdilution method. Carbapenemase-encoding genes (bla KPC , bla NDM , bla IMP , bla VIM , and bla OXA-48-like ) were studied for the isolates that were not susceptible to any carbapenems. Sequencing analysis of the mcr genes (mcr-1-5) was conducted for all isolates with colistin MICs ≥4 mg/L. Results: Ertapenem non-susceptibility was detected in 3% (n=3) E. coli and 12% (n=12) K. pneumoniae isolates. The susceptibility rates of imipenem, ceftazidime-avibactam (CAZ-AVB), and ceftolozane-tazobactam (CLZ-TAZ) were 99%, 99%, and 88%, respectively, for E. coli, 91%, 100%, and 80%, respectively, for K. pneumoniae, and 66%, 91%, and 93%, respectively, for P. aeruginosa. Carbapenemase-encoding genes were not detected in E. coli, were detected in four (33.3%) K. pneumoniae isolates that were not susceptible to ertapenem (three harboring blaKPC and one harboring blaOXA-48-like), and were not detected in P. aeruginosa isolates that were not susceptible to imipenem. One K. pneumoniae isolate was resistant to colistin (MIC 4 mg/L) and negative for mcrgenes. Conclusion: CAZ-AVB exhibited excellent activity against carbapenem-resistant Enterobacteriaceae, and CLZ-TAZ exhibited good activity against imipenem-resistant P. aeruginosa.

Original languageEnglish
Pages (from-to)545-552
Number of pages8
JournalInfection and Drug Resistance
Publication statusPublished - Jan 1 2019



  • Carbapenem resistance
  • Carbapenemase-encoding genes
  • Mcr
  • Second-generation
  • β-lactam
  • β-lactamase inhibitor combinations

ASJC Scopus subject areas

  • Pharmacology
  • Infectious Diseases
  • Pharmacology (medical)

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