In vitro antimicrobial activity of tigecycline against multidrug-resistant Acinetobacter baumannii strains

Abstract number: 1733_1537

Karaman S., Arslan H., Timurkaynak F., Kurt Azap Ö.

Introduction:Acinetobacter baumannii strains are important multidrug-resistant nosocomial pathogens especially in the intensive care unit. Tigecycline, member of glycylcylines, exhibits antibacterial activity against multidrug-resistant Gram-negative strains.

The aim of this study is to determine the antibacterial activity of tigecycline against the multidrug-resistant A. baumannii strains isolated from the blood cultures of the patients hospitalised in the intensive care unit.

Materials and Methods: Multidrug-resistant A. baumannii strains isolated from the patients hospitalised in the intensive care unit between the period January 2005-April 2006 were included in the study. Bacteria were identified to the species level by conventional methods and automated identification kits. Each isolate was obtained from one patient. Antimicrobial activities of ceftazidime, cefepime, piperacillin-tazobactam, amikacin, ciprofloxacin and imipenem were studied according to the CLSI criteria. Minimal inhibitory concentrations of tigecycline against 39 A. baumannii strains of which were resistant to at least four of the drugs above were studied by E test strips. ≤ 2 mg/L was chosen as the susceptibility breakpoint according to the other studies.

Results: MIC50 and MIC90 values were found to be 1.5 mg/L and 2 mg/L respectively, within a range of 0.75–4 mg/L. The susceptibility rate of the strains were determined to be 94.7%.

Conclusion: MIC50 and MIC90 values of tigecycline against multidrug-resistant A. baumannii strains were found to be high as in the other studies. However, tigecycline seems to be an alternative for the infections caused by resistant pathogens because of the high susceptibility rate (94.2%). Further studies including higher numbers of strains are needed to determine the value of tigecycline in the treatment of the infections caused by multidrug-resistant A. baumannii strains.

Session Details

Date: 31/03/2007
Time: 00:00-00:00
Session name: European Society of Clinical Microbiology and Infectious Diseases
Location: ICC, Munich, Germany
Presentation type:
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