Colistin-sparing regimens against Klebsiella pneumoniae carbapenemase-producing K. pneumoniae isolates: Combination of tigecycline or doxycycline and gentamicin or amikacin

Hung Jen Tang, Chih Cheng Lai, Chi Chung Chen, Chun Cheng Zhang, Tzu Chieh Weng, Yu Hsin Chiu, Han Siong Toh, Shyh Ren Chiang, Wen Liang Yu, Wen Chien Ko, Yin Ching Chuang

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7 Citations (Scopus)


Background/Purpose: In vitro studies of the combination of an aminoglycoside with tigecycline or doxycycline against Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae isolates are rarely published. The goal of this study was to evaluate the antibacterial activity of the combination regimens. Methods: Thirteen genetically different KPC-producing K. pneumoniae isolates were randomly selected. Drug concentrations of amikacin, gentamicin, tigecycline, and doxycycline were adjusted to 1-, 1/2-, and 1/4-fold of respective minimum inhibitory concentrations (MICs). Each drug alone or the combinations of amikacin or gentamicin with tigecycline or doxycycline were tested by combination studies. Results: Treatment with the 1× MIC concentration in combinations of amikacin or gentamicin and tigecycline or doxycycline for 24 hours resulted in bactericidal activity of 84-100% in the isolates. Treatment with 1/2× MIC combinations resulted in synergism of 69-100% in the isolates. Notably, doxycycline plus gentamicin or amikacin was synergistic for all tested isolates. However, bactericidal or synergistic effect was barely evident following 1/4× MIC combinations. There was no antagonism in any of the combination regimens. Conclusion: Enhanced activity was noted following treatment with doxycycline combined with gentamicin or amikacin against KPC-producing K. pneumoniae isolates, warranting further in vitro and animal investigations before clinical application.

Original languageEnglish
Pages (from-to)273-281
JournalJournal of Microbiology, Immunology and Infection
Issue number2
Publication statusPublished - Apr 1 2019
Externally publishedYes



  • Aminoglycoside
  • Doxycycline
  • KPC
  • Synergism
  • Tigecycline

ASJC Scopus subject areas

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

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