Actinomycetes

They are Gram positive filamentous bacteria with branching filaments which resemble fungi. Infection is indolent and characterised by the presence of yellow sulfur granules which are actually clumps of bacteria. It presents as a granulomatous or suppurative inflammation with draining sinuses extruding sulfur granules. Classic locations are oral (lumpy jaw) and cervicofacial, thoracic, abdominopelvic area, musculoskeletal or CNS.

Local trauma precedes the infection helping the bacteria gain access to the subcutaneous tissue. Interestingly, pelvic actinomycosis has been seen in some IUD (intrauterine device) users. For diagnosis, granules are crushed between slides and Gram stained to show “sunray appearance”. Culture can be done anaerobically on Brain heart infusion broth or thioglycollate broth.