ABSTRACT
The term actinomycete is an informal designation for Šlamentous gram-positive bacteria with high G + C content in their genome and that belong to the order Actinomycetales in the class Actinobacteria.1,2 Most aerobic actinomycetes are soil saprophytes and are rarely encountered in clinical practice, but some are serious pathogens of humans and animals causing a number of diseases that include actinomycetoma, actinomycosis, and nocardiosis. The clinical manifestations and severity of the disease and the prognosis in an infected host are extremely variable and may be determined by factors such as the route of infection and the presence or absence of a properly functioning immune system.3 The diagnosis of actinomycete infections has been hindered by a combination of clinical and microbiologic difŠculties, including their often nonspeciŠc clinical presentation, a requirement for invasive diagnostic biopsy procedures, difŠculty in isolation, and incorrect identiŠcation.
