Prevalence of cervical colonization by Ureaplasma parvum, Ureaplasma urealyticum, Mycoplasma hominis and Mycoplasma genitalium in childbearing age women by a commercially available multiplex real-time PCR: An Italian observational multicentre study.

BACKGROUND: Mycoplasmas are frequently isolated from the genital tract. New molecular PCR-based methods for the detection of mycoplasmas can better define the real epidemiology of these microorganisms. The aim of this study was to evaluate the prevalence of mycoplasmas in a population of childbearing age women by means of PCR. METHODS: This 21-month multicentre observational study was conducted at four Italian clinical microbiology laboratories. Women reporting symptoms of vaginitis/cervicitis, or with history of infertility, pregnancy, miscarriage or preterm birth were included. Detection of Ureaplasma parvum, Ureaplasma urealyticum, Mycoplasma hominis, Mycoplasma genitalium was performed from cervical swabs by means of a commercially available multiplex real-time PCR. RESULTS: a total of 1761 women fulfilled the inclusion criteria and were included in the study. The overall prevalence was: U. parvum 38.3%, U. urealyticum 9%, M. hominis 8.6% and M. genitalium 0.6%. The proportion of foreign patients positive for U. parvum was significantly higher compared to Italian patients (37% vs 30.1%, p = 0.007) and also for overall mycoplasma colonization (53.4% vs 45.8%, p = 0.011). The number of symptomatic patients positive for M. hominis was significantly higher than that of negative controls (2.9% vs 1%, p = 0.036). A significant positive trend in mycoplasma colonization was found in relation to the pregnancy week for U. urealyticum (p = 0.015), M. hominis (p = 0.044) and for overall mycoplasma colonization (p = 0.002). CONCLUSION: multiplex RT-PCR can be a valuable tool to evaluate the real epidemiology of cervical mycoplasma colonization.

Molecular sensitivity threshold of wet mount and an immunochromatographic assay evaluated by quantitative real-time PCR for diagnosis of Trichomonas vaginalis infection in a low-risk population of childbearing women.

Vaginal trichomoniasis is a sexually transmitted infection caused by Trichomonas vaginalis, a flagellated protozoan. Diagnosis of T. vaginalis infection is mainly performed by wet mount microscopy, with a sensitivity ranging from 38% to 82%, compared to culture, still considered the gold standard. Commercial immunochromatographic tests for monoclonal-antibody-based detection have been introduced as alternative methods for diagnosis of T. vaginalis infection and have been reported in some studies to be more sensitive than wet mount. Real-time PCR methods have been recently developed, with optimal sensitivity and specificity. The aim of this study was to evaluate whether there is a molecular sensitivity threshold for both wet mount and imunochromatographic assays. To this aim, a total of 1487 low-risk childbearing women (median age 32 years, interquartile range 27-37) were included in the study, and underwent vaginal swab for T. vaginalis detection by means of a quantitative real-time PCR assay, wet mount and an immunochromatographic test. Upon comparing the results, prevalence values observed were 1.3% for real-time PCR, 0.5% for microscopic examination, and 0.8% for the immunochromatographic test. Compared to real-time PCR, wet mount sensitivity was 40% (95% confidence interval 19.1% to 63.9%) and specificity was 100% (95% CI 99.7% to 100%). The sensitivity and specificity of the immunochromatographic assay were 57.9% (95% CI 33.5% to 79.8%) and 99.9% (95% CI 99.6% to 100%), respectively. Evaluation of the wet mount results and those of immunochromatographic assay detection in relation to the number of T. vaginalis DNA copies detected in vaginal samples showed that the lower identification threshold for both wet mount (chi-square 6.1; P = 0.016) and the immunochromatographic assay (chi-square 10.7; P = 0.002) was ≥100 copies of T. vaginalis DNA/5 mcl of eluted DNA.