Methods for testing antibiotic sensitivity of anaerobic bacteria

Problems are still encountered in the performance and interpretation of tests of anaerobe sensitivity to antibiotics. A review of the methods currently used was carried out in order to determine factors modifying the activity of antibiotics. The sensitivity of Escherichia coli, Staphylococcus aureus and Clostridium perfringens to various drugs was tested under different conditions (including different culture media and incubation atmospheres). Gentamicin and kanamycin showed no activity in tests with brain heart infusion agar incubated anaerobically or in 10% CO2. The activity of lincomycin was much more readily influenced by test conditions than that of clindamycin. All the drugs examined except gentamicin and kanamycin showed more activity when tested in brain heart infusion agar than in Mueller Hinton blood agar.