In vitro antibacterial activity of tigecycline against resistant Gram-negative bacilli and enterococci by time-kill assay Article

Full Text via DOI: 10.1016/j.diagmicrobio.2009.03.023 PMID: 19501791 Web of Science: 000267277300010

Cited authors

  • Pankey, George A.; Ashcraft, Deborah S.


  • This time-kill study was performed with 65 genetically unique clinical isolates of Gram-negative bacilli and enterococci to further define the antibacterial activity of tigecycline. To our knowledge, this is the largest published time-kill study evaluating tigecycline activity to date. Isolates evaluated were 10 meropenem-resistant Acinetobacter baumannii; 15 Escherichia coli, including 10 extended-spectrum beta-lactamase (ESBL) producers; 15 Klebsiella pneumoniae, including 10 ESBL producers; 20 vancomycin-resistant Enterococcus faecium (VRE), including 10 that were linezolid resistant; and 5 vancomycin-susceptible Enterococcus faecalis. Time-kill testing was performed using tigecycline concentrations of 1x, 2x, and 4x MIC with colony-forming units (CFU) per milliliter determined at 0, 4, 8, 12, 24, 36, and 48 h. Tigecycline MICs (mu g/mL) were <= 1 for E. coli and K. pneumoniae, regardless of the isolates' ESBL production; A. baumannii, 0.06 to 4; 9/10 (90%) were <= 2; E. faecalis <= 0.12; and VRE <= 0.25, regardless of linezolid susceptibility. In the time-kill assay, tigecycline significantly inhibited bacterial growth when compared with the growth control. The reduction in growth was <3 log(10) CFU/mL for all isolates, indicative of a bacteriostatic effect. (C) 2009 Elsevier Inc. All rights reserved.

Publication date

  • 2009

International Standard Serial Number (ISSN)

  • 0732-8893

Start page

  • 300

End page

  • 304


  • 64


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