Determinación de una técnica de referencia para la susceptibilidad antimicrobiana de bacterias anaeróbicas de importancia clínica

Abstract

The selection of antibiotics for the treatment of anaerobic infections is generally based on purely empirical criteria, with antimicrobial sensitivity tests being carried out only in reference centres. For this reason, it is important to investigate a technique appropnate for use in less specialized clinical bacteriology laboratories. In this study, four antimicrobial sensitivity tests (elution in a broth disk, macrodilution, rnicrodilution and dilution in agar) were carried out using four reference strains with known sensitivity patterns. The reproducibility, concordance, speed and ease of use of each test was compared. The results obtained showed that the most reproducibletest was dilution in agar, followed by microdilution, macrodilution and elution. In terms of concordance the best test was dilution in agar, followed by macrodilution, elution and microdilution. The most complex test was dilution in agar, followed by microdilution, macrodilution and elution. As this study did not find any single test which, aione, proved better than any other in all the criteria analized, we recommend that a combination of at least two tests be used in the study of antimicrobial susceptibility of anaerobes.