Comparison of fluorescent antibody technique and conventional staining methods in diagnosis of cervico-facial actinomycosis.

Eight formalin-fixed and paraffin-embedded biopsies with a histopathology suggestive of actinomycosis, were tested with fluorescent antibody technique using antiserum specific against Actinomyces israelii. The method was found effective even in decalcified tissue material. Positive fluorescent staining resulted, not only in the colonies but also in the surrounding cells, suggesting the presence of intracellular Actinomyces antigens. The possibility of retrospective biopsy study is very helpful in cases of prolonged infections. Grocott's stain was found to be most effective conventional method for screening suspected actinomycosis.