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Tigecycline activity tested against 22,950 bloodstream infection isolates worldwide

Abstract number: 1134_02_20

Jones R., Sader H., Stilwell M., Fritsche T.

Objective:

To assess the activity of tigecycline (formerly GAR936), a novel glycylcycline, against recent bloodstream infection (BSI) pathogen isolates from six continents. Frequency of clinical occurrence of these pathogens was determined and their antibiograms assessed using NCCLS reference broth microdilution methods.

Methods:

A total of 22,950 strains were tested by the M7–A6 (2003) method with interpretations from M100–S14 (2004). A tigecycline susceptible (S) breakpoint was defined as <=2 mg/L for comparison purposes only, although <=4 mg/L has been used for tetracyclines. The rank order of pathogens was: S. aureus (SA; 34.2%), coagulase-negative staphylococci (CoNS; 14.1%), E. coli (EC; 13.2%), enterococci (ENT; 12.7%), Klebsiella spp. (KSP; 5.3%), P. aeruginosa (PSA; 4.0%), Enterobacter spp. (EBS; 2.9), beta-haemolyticstreptococci (BST; 2.8%); S. pneumoniae (SPN; 2.4%), and viridans group streptococci (VgS; 1.6%). More than 20 comparison agents were tested including tetracycline (TC) and ciprofloxacin (CIP).

Results:

BSI pathogens (Gram-positive and Enterobacteriaceae) tested against tigecycline are shown in the table. Tigecycline was consistently active against TC-resistant (R) strains (89–100% S versus 45–90%). MIC50:% S results for other BSI species were: P. mirabilis (4 mg/L:10), Acinetobacter spp. (0.5 mg/L:77), Serratia spp. (1 mg/L:81), S. maltophilia (1 mg/L:77) and indole-positive Proteae (1 mg/L:54). Tigecycline exhibited a broader spectrum of activity against BSI isolates when compared to CIP, TC, older aminoglycosides and imipenem. Tigecycline was not active against PSA (MIC50, 8 mg/L; 4.0% of BSI isolates).

Conclusions:

Tigecycline exhibited a wide spectrum of antimicrobial potency versus BSI isolates collected worldwide. Serious infections in nosocomial environments should benefit from tigecycline among the investigational Phase 3 agents focused on R strains.

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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