Actinomyces infection. Light micrograph of a cervical smear showing infection by the opportunistic pathogen Actinomyces. Actinomyces infection is seen here as an aggregation of organisms in large black sulfur granules with small black-stained bacteria seen on the periphery. Actinomyces is a filamentous bacterium that branches freely and resembles fungal hyphae. Cervical infection is associated with the use of an inter-uterine contraceptive device (IUD) and may lead to pelvic inflammatory disease. IUDs encrusted with Actinomyces can rupture the uterine wall, causing actinomycetoma. Papanicolaou stain. Magnification: x100 at 35mm size.