Real-time PCR detection of the mg219 gene of unknown function of Mycoplasma genitalium in men with and without non-gonococcal urethritis and their female partners in England

Abstract

Real-time PCR was employed to detect a region of the Mycoplasma genitalium mg219 gene, a gene of unknown function, in clinical samples. Amplification of DNA and signal production from 15 other species of human mycoplasmas and 14 other bacteria and viruses did not occur. Using a panel of 208 genital and rectal samples, the sensitivity when compared to the modified mgpa gene (encoding the major surface protein MgPa) real-time PCR assay was found to be 100 % and the specificity of the assay 99.5 % with a positive predictive value of 80 % and a negative predictive value of 100 %. The mg219 gene was found to be in all strains of M. genitalium and was highly conserved. M. genitalium was detected in 3.9 % (11/280, 95 % CI 2.1–6.9) of all male specimens, in 7.7 % (10/130, 95 % CI 4.1–13.7) of patients with non-gonococcal urethritis (NGU) and in 0.7 % (1/150, 95 % CI <0.01–4.1) of patients without urethritis. The presence of M. genitalium was significantly associated with NGU (P ≤0.01; 95 % Cl 0.88–0.98) and non-chlamydial-non-gonococcal urethritis (P=0.0005; 95 % Cl 0.84–0.97).