Blee`S

Microbiología

Estudio de susceptibilidad a tigeciclina: Influencia del agar Mueller-Hinton en el método de difusión en agar y validación del método E-test® para Acinetobacter baumannii
PatriciaGarcía C., Lorena Porte T. y Daniel Curcio J.

In vitro evaluation of tygecicline: Influence of Mueller-Hinton agar in agar diffussion methods and validation of E-test® for Acinetobacter baumanniiTigecycline is a glicylcicline with broad antimicrobial spectrum. Susceptibility testing to this drug for Acinetobacter is difficult in hospitals due to the utilization of the disk diffusion method.FDA break points have shown an unacceptable rate of errors (23%) for disk diffusion versus broth microdilution in American studies and overcall of resistance depending on the brand of Mueller Hintonagar used. Modifications to these FDA break points have been proposed, but there is not enough evidence yet. Data from a multicenter study from Chile allowed the evaluation of the characteristics of theagar used for susceptibility testing and the utility of E-test as an alternative MIC method for Acinetobacter. The Mueller Hinton agar brand is an important factor that affects disk diffusion methodresults. There is very good correlation between broth microdilution and E-test for the susceptibility category as well as for MIC determination. The intermediate and resistant results obtained withdisk diffusion method should be checked by using E-test. Key words: Tigecycline, antibiograms, bacterial sensitivity tests, minimum inhibitory concentration, disk diffusion antimicrobial tests. Palabrasclave: Tigeciclina, antibiogramas, test de sensibilidad bacteriana, concentración inhibitoria mínima, test de difusión por disco.

Pontificia Universidad Católica de Chile, Santiago Departamento deLaboratorios Clínicos Laboratorio de Microbiología (PGC) Hospital Militar de Santiago, Chile Laboratorio Clínico (LPT) Buenos Aires, Argentina Sanatorio Itoiz (DCJ) Correspondencia a: Patricia...