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Tigecycline Evaluation Surveillance Trial (TEST) – Global in vitro antibacterial activity against Gram-positive and Gram-negative pathogens

Abstract number: 1134_02_9

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

Background:

Tigecycline, a member of a new class of antimicrobials (glycylcyclines), has been shown to have potent expanded broad spectrum activity against most commonly encountered species responsible for community and hospital acquired infections. The TEST program determined the in vitro activity of tigecycline compared to amikacin, ampicillin, imipenem, cefepime, ceftazidime, ceftriaxone, levofloxacin, minocycline, and piperacillin/tazobactam against gram negative rods in addition to linezolid, penicillin, and vancomycin for the gram positive species. Isolates were collected from hospitals in North America, Europe and Asia throughout 2004.

Methods:

A total of 6383 clinical isolates were identified to the species level at each participating site and confirmed by the central laboratory. Minimum Inhibitory Concentration (MICs) were determined by the local laboratory using supplied broth microdilution panels and interpreted according to NCCLS guidelines.

Results:

As shown in the table below, tigecycline's activity was similar to imipenem against Enterobacteriaceae. It inhibited multi-resistant ESBL and AmpC producers with a MIC equal or lesser than 2 mcg/ml. Although similar to other classes of broad spectrum antimicrobial agents against non-fermenters, tigecycline was especially active against Acinetobacter spp. demonstrating the lowest MIC90 of 2 mcg/ml. Tigecycline successfully inhibited S. aureus with MIC90 of 0.25 mcg/ml regardless of sensitivity or resistance to methicillin. The same results were noticed against enterococci. Tigecycline's MIC90 was consistent regardless of vancomycin susceptibility.

Conclusion:

Tigecycline's in vitro activity was comparable to or greater than most commonly prescribed antimicrobials. The presented data suggest that tigecycline may be an effective and reliable therapeutic option against both aerobic gram-positive and aerobic gram-negative bacteria, including multi-drug resistant strains regardless of degree or type of resistance.

Table for P809

 Enterobacteriaceae (n=3,804)P.aeruginosa (n=449)Acinetobacter spp. (n=612)S. aureus (n=733)Enterococcus spp. (n=785)
RangeMIC50MIC90RangeMIC50MIC90RangeMIC50MIC90RangeMIC50MIC90RangeMIC50MIC90 
Tigecycline0.03–160.25010.06–>168>160.008–4120.03–10.120.250.3–0.50.060.12
Amikacin0.5–>6424<=0.5–>64480.5–>648>64      
Ampicillin0.5–>32>32>324–>32>32>328–>32>32>320.06–>1616>160.25–>161>16
Cefepime0.5–>320.52<=0.5–>324320.5–>3232>32      
Ceftazidime8–>32816<=8–>32<=8328–>32>32>32      
Ceftriazone0.06–>640.068<=0.06–>64>64>640.12–>64>64>640.5–>648>641–>64>64>64
Imipenem0.12–>160.510.25–>16180.25–>161160.12–>160.25>160.25–>161>16
Levofloxacin0.008–>80.068<=0.008–>82>80.15–>8>8>80.06–>320.5>320.25–>3232>32
Minocycline0.5–>1628<=0.5–>16>16>160.5–>16180.25–>80.250.50.25–>88>8
Pip/tazobactam0.06–>1281160.12–>12841280.06–>12864>1280.25–>162>160.5–>164>16
Penicillin         0.06–>8>8>80.5–>84>8
Linezolid         0 5–4220.5–>822
Vancomycin         0.25–4110.25–>321>32

Session Details

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