Rapid PCR Detection of Mycoplasma hominis, Ureaplasma urealyticum, and Ureaplasma parvum

Objective. We compared laboratory developed real-time PCR assays for detection of Mycoplasma hominis and for detection and differentiation of Ureaplasma urealyticum and parvum to culture using genitourinary specimens submitted for M. hominis and Ureaplasma culture. Methods. 283 genitourinary specimens received in the clinical bacteriology laboratory for M. hominis and Ureaplasma species culture were evaluated. Nucleic acids were extracted using the Total Nucleic Acid Kit on the MagNA Pure 2.0. 5？μL of the extracts were combined with 15？μL of each of the two master mixes. Assays were performed on the LightCycler 480 II system. Culture was performed using routine methods. Results.？？M. hominis PCR detected 38/42 M. hominis culture-positive specimens, as well as 2 that were culture negative (sensitivity, 90.5%; specificity, 99.2%). Ureaplasma PCR detected 139/144 Ureaplasma culture-positive specimens, as well as 9 that were culture negative (sensitivity, 96.5%; specificity, 93.6%). Of the specimens that tested positive for Ureaplasma species, U. urealyticum alone was detected in 33, U. parvum alone in 109, and both in 6. Conclusion. The described PCR assays are rapid alternatives to culture for detection of M. hominis and Ureaplasma species, and, unlike culture, the Ureaplasma assay easily distinguishes U. urealyticum from parvum. 1. Introduction Mycoplasma hominis, Ureaplasma urealyticum, and Ureaplasma parvum are small, fastidious bacteria belonging to the Mollicutes class. They lack a cell wall (preventing staining with Gram stain) and are not sensitively detected on routine bacterial cultures. Optimal recovery requires specialized media and growth conditions. There are several human pathogens in the genera Mycoplasma and Ureaplasma which are responsible for a variety of clinical manifestations involving multiple body systems [1]. M. hominis causes septic arthritis and postpartum fever and has been associated with pelvic inflammatory disease and bacterial vaginosis [2]. Ureaplasma species can cause acute urethritis and have been associated with bacterial vaginosis, preterm birth, and neonatal respiratory disease [1, 3]. Although M. hominis and Ureaplasma species can be cultured, this requires technical skill for interpretation of microscopic colonies and takes two to five days. U. urealyticum was the only Ureaplasma species until 2002, when U. parvum was described [4]. The two are not distinguished based on culture characteristics alone. Real-time PCR detection of these microorganisms from clinical samples circumvents technical issues related to culture