Revista argentina de microbiología
versión On-line ISSN 1851-7617
ZARATE, M. S.; SERRUTO, G. y SMAYEVSKY, J.. In vitro activity of tigecycline in clinical isolates of multidrug resistant Acinetobacter spp. Comparison of different methods of evaluation. Rev. argent. microbiol. [online]. 2010, vol.42, n.1, pp. 53-56. ISSN 1851-7617.
Infections caused by multidrug resistant (MDRA) Acinetobacter spp. have increased worldwide. Tigecycline provides a new therapeutic option for treating these infections. We conducted a study tailored to validate an in house methodology by broth microdilution (BM) vs. commercial BM in 32 MDRA isolates. Sixty MDRA isolated in 2 time periods (2000-2003 and 2006-2008) were compared by BM, agar dilution (AD) and disk diffusion (DD) methods, as described by the CLSI and the MIC90 for each period was determined. Susceptibility was interpreted by using the breakpoints suggested by the FDA for Enterobacteriaceae. The correlation between the methodologies was performed by a scattergram, and the errors between methods were calculated. The correlation coefficients between AD and BM, and BM and DD were, r: 0.68 in both cases. For 2002-2003, the MIC90 for BM was: 1 g/ml, and for 2006-2008: 2 μg/ml. Using the FDA breakpoints for DD, we observed an unacceptable minor error (17.6%) because of false-intermediate values, considering the MIC90 was 1-2 μg/ml.
Palabras clave : Tigecycline; Acinetobacter spp.; Multidrug resistance.