Demonstration of Actinomyces and Arachnia species in cervicovaginal smears by direct staining with species-specific fluorescent-antibody conjugate

Abstract

For direct observation of microaerophilic actinomycetes by fluorescent antibody, a procedure was developed in which pepsin treatment and rhodamine conjugate of normal serum were used to reduce nonspecific staining in cervicovaginal smears. Actinomyces israelii, Actinomyces naeslundii, and Arachnia propionica were observed in cervicovaginal smears from women who did use and who did not use an intrauterine contraceptive device. A. israelii was found more commonly in women with an intrauterine contraceptive device, but no evidence was obtained that the use of an intrauterine contraceptive device influenced the presence of either A. propionica or A. naeslundii.

PIP: A procedure was developed for the direct observation of microaerophilic actinomycetes by fluorescent antibody. In the procedure pepsin treatment and rhodamine conjugate of normal serum were used to reduce nonspecific staining in cervicovaginal smears. Observations of "A. israelli," "A. naeslundii." and "A. propionica" in cervicovaginal smears are reported. These organisms were identified by direct staining with flurescein isothiocyanate (FITC)-labeled rabbit globulin specific for each organism and by observing for a typical actinomycete morphology. In initial experiments with FITC conjugates, "A. israelli" could not be demonstrated in tissue sections known to be positive by culture and Gram stain. By using the conjugates specific for each species, examination of the sections of endometrium and endocervix showed actinomycotic filaments staining only with the anti-"A. israelli" conjugate. Examination of cervicovaginal smears from the first 25 patients with phase-control microscopy were not suitable for observations of actinomycete elements. Of the smears from the 19 patients with an IUD, 39% were postive for "A. israelli," and 17% were positive for "A. propionica." None of the smears was positive for "A. naeslundii." Only 12% and 6% of the slides from 32 patients without an IUD stained positively for "A. israelli" and "A. naeslundii," respectively.