An Indirect Immunofluorescence Method for Detection of Mycoplasma hominis in Vaginal Smears

Abstract

We developed a novel method for the detection of Mycoplasma hominis from vaginal swabs using an indirect immunofluorescence technique. It is a rapid and simple method that can be finished in only 5 hr and is more sensitive than the usual culture isolation method. The indirect immunofluorescence method was applied to vaginal smears from 193 healthy women and 33.7% gave a positive test. This value was much higher than that (11.4%) obtained from the same specimens by the culture method. When vaginal smears were subjected to Papanicolaou staining after the indirect immunofluorescence method, the specific immunofluorescence of the epithelial cells was located exactly at the sites of granular aggregates stained with Papanicolaou stain. A histological examination by Papanicolaou staining showed that the incidence of inflammation seems to be slightly higher in M.carriers than in non-carriers.Mycoplasma hominis is a microorganism found in the human urogenital tract (21) and is transmitted by sexual contact (13,14). The colonization of the organism in the genital tract is associated with preterm birth, prematurity and low birth weight (2, 10). It has also been regarded as being casually associated with urethritis, prostatitis, postpartum fever, salpingitis and pyelonephritis (3,18). Further, extra-urogenital infections caused by M. hominis have been reported (11,17,19,22). An epidemiological study on the carriers of M. hominis is important for an understanding of its etiologic role in urogenital inflammations, as well as in terms of public health. Observation of Japanese healthy young women done by Kanamoto et al (12) showed that 8.8% of the pregnant women were colonized with the organism. The prevalence of the organism in healthy women in other countries varies from 5.3 to 48.8%, depending on the investigators (4,20). In order to investigate the spread of this organism among Japanese women and the incidence of inflammatory diseases in carriers, we examined specimens collected from 193 volunteers. In general, the laboratory diagnosis of M. hominis is carried out by culture isolation, followed by specific differentiation using specific antisera. Confirmative diagnosis 831