Actinomycetoma with negative culture: a therapeutic challenge.

Nocardia, Actinomyces, and Streptomyces species comprise the three broad classes of organisms that are causative for bacterial mycetoma. Although culture and molecular laboratory studies can usually identify the precise etiologic agent in bacterial mycetoma, occasionally these methods fail to clarify this situation. We report a classic clinical case of this infectious disease where usual diagnostic methods failed to identify the responsible organism, and discuss the empiric approach to such cases.