Abstract
The susceptibility of 26 isolates of Nocardia asteroides to several antibiotics was determined by the agar dilution technique. Many currently available beta-lactam antibiotics were ineffective. Cefotaxime, cefmenoxime, and N-formimidoyl thienamycin were active against these strains, with 80% minimal inhibitory concentrations of 4, 4, and 2 micrograms/ml, respectively. Amikacin was the most effective agent tested.