In vitro activity of selected antibiotics against anaerobes.

Testing antibiotics for their activity against microorganisms is fraught with problems. The various methods and media yield different results, and controversy exists as to which is the most reliable. The technique used in our laboratory has shown wide differences in the susceptibility patterns of Bacteroides strains and other anaerobes to different antibiotics. Particularly with respect to the third-generation cephalosporins, reliable clinical data are needed to determine which in vitro tests most accurately predict clinical efficacy.