Objectives Mycoplama genitalium is a sexually transmitted organism associated with non-gonococcal urethritis in men and several inflammatory reproductive tract syndromes in women. Nucleic acid amplification tests are currently the only available methods for detection. The first commercially available real-time (RT-) PCR kits have been recently developed. We compared the TIB MOLBIOL LightMix® Kit Mycoplasma genitalium and the Diagenode Mycoplasma genitalium real-time PCR kit to the in-house TaqMan RT-PCR used routinely for the M. genitalium diagnostic.
Methods DNA extracts from 50 M. genitalium-negative and 53 M. genitalium-positive urogenital specimens collected between January 2010 and May 2011 at the Bordeaux University hospital, France, were retrospectively and systematically selected and thawed. DNA had been extracted using the MagNA Pure DNA isolation kit I (Roche Diagnostics). DNA extracts were evaluated by the TIBMOLBIOL LightMix® Kit Mycoplasma genitalium and the Diagenode Mycoplasma genitalium real-time PCR kit (DIA-MG-050 vs2) in comparison with a M. genitalium in-house RT-PCR targeting the MgPa adhesin gene using the cobas z480 analyser (Roche Diagnostics).
Results The in-house PCR was first evaluated using two thermal cyclers, LC480 and cobas z480 (Roche Diagnostics). As no significant difference was noted, the cobas z480 was used in the rest of the study. The clinical sensitivity was 98%, 92% and 100% for the LightMix® Kit Mycoplasma genitalium, the Diagenode Mycoplasma genitalium real-time PCR kit and the in house RT-PCR, respectively. The clinical specificity was 100% for both kits and 94% for the in house RT-PCR. There was no statistically significant difference between the clinical sensitivity and specificity of these 3 methods. Moreover, there was no statistically significant difference between the cycle threshold mean of the in-house assay and those of both commercial kits.
Conclusion Both commercial kits allowed prompt and specific results, validated by the use of an internal amplification control.
- Mycoplasma genitalium
- Real-time PCR