Tigecycline Evaluation Surveillance Trial (TEST) – Global in vitro antibacterial activity against selected species of glucose non-fermenting organisms

Abstract number: 1134_02_11

Bouchillon S., Stevens T., Johnson B., Johnson J., Hoban D., Hackel M., Person M., Dowzicky M.


Glucose non-fermenting gram negative rods are known to be highly resistant in hospital settings and have always been a challenge for clinicians and hospital infection control. The degree or type of resistance may be due to several sophisticated mechanisms such as production of broad spectrum beta-lactamases, efflux pumps and altered membrane permeability, inactivating most classes of antimicrobials that are available for treatment (cephalosporins, carbapenems, aminoglycosides, fluoruquinolones). Tigecycline, a member of a new class of antimicrobials (glycylcyclines), has been shown to have potent expanded broad spectrum activity against most species of Enterobacteriaceae and selected species of non-fermenters, as well as Gram positives, atypicals and anaerobes. The TEST program determined the in vitro activity of tigecycline compared to amikacin, ampicillin, imipenem, cefepime, ceftazidime, ceftriaxone, levofloxacin, minocycline and piperacillin/tazobactam against members of Acinetobacter spp. and Pseudomonas aeruginosa collected from hospitals in North America, Europe and Asia.


A total of 2513 non-fermenting clinical isolates were identified to the species level at each participating site and confirmed by the central laboratory. Isolates were collected throughout 2004. Minimum Inhibitory Concentration (MICs) were determined by the local laboratory using supplied broth microdilution panels and interpreted according to NCCLS guidelines.


The cephalosporins were ineffective towards A. baumannii (n = 424). Tigecycline showed the lowest MICs against A. baumannii with a MIC50/MIC90 of 0.5/2 mcg/ml, outperforming amikacin, 74.3% inhibition MIC50/MIC90 4/64, imipenem, 79.5% MIC50/MIC90 0.5/16, and minocycline, 85.4% MIC50/MIC90 1/8. Similar findings were found in other species of the Acinetobacter genus.


The presented data suggest that tigecycline may be an effective and reliable therapeutic option against strains of Acinetobacter spp., including multi-drug resistant strains regardless of degree or type of resistance.

Session Details

Date: 01/08/2007
Time: 00:00-00:00
Session name: XXIst ISTH Congress
Location: Oxford, UK
Presentation type:
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