Drug-resistant Nocardia asteroides infection in a patient with acquired immunodeficiency syndrome.

We have reported what we believe to be the first case of disseminated infection due to a multiply drug resistant strain of Nocardia asteroides in a patient with the acquired immunodeficiency syndrome and concomitant disseminated histoplasmosis. This strain of the organism fits a pattern of susceptibility that is rare among N asteroides isolates in general and has been called the type 5 pattern, described as a resistance to broad spectrum cephalosporins, ciprofloxacin, and all aminoglycosides except amikacin. The recognition of disease due to this group of organisms is especially important in patients with AIDS because sulfonamides, considered the drugs of choice for treatment of N asteroides infection, are associated with a high incidence of adverse effects in these patients.