Article Text
Abstract
Background The objectives of this study were to determine the limits of detection (LODs) of Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and Mycoplasma genitalium (MG), using Aptima Combo 2 for CT/NG and Aptima Mycoplasma genitalium assays in presence of different volumes of semen and ESwab medium (bioMérieux, France) used for specimen collection. Furthermore, the preservation conditions of these bacteria in ESwab medium were assessed.
Methods Semen specimens were collected anonymously from patients consulting at the reproductive biology department of Bordeaux University Hospital. To determine LOD, quantified cultures of each bacterium were spiked in semen or ESwab medium. Different volumes added to APTIMAÒ Specimen transfer tubes were tested with Aptima Combo 2 CT/NG and Aptima Mycoplasma genitalium assays. Storage conditions (5 days at room temperature and 7 days at 4°C) of each bacterium in ESwab medium were evaluated. All the experiments were performed in triplicate on the HologicÒ Panther system.
Results The semen was a slight source of amplification inhibition for CT and MG. However, using a volume of 50 µL of semen, the LOD of CT, NG and MG in semen remained low, at 103 IFU/mL, 10 CFU/mL and 102 CCU/mL, respectively. A volume of 50 µL of semen could be chosen for the diagnostic of these bacteria with Aptima assays. In ESwab medium, the LODs of CT, NG and MG were equivalent (between 1 and 10 IFU, CFU or CCU/mL) whatever the volume of ESwab added in the APTIMAÒ specimen transfer tubes. A volume of 200 µl of ESwab allowed performing several different Aptima assays and the LOD of bacteria remained low whatever the storage conditions.
Conclusion Aptima Combo 2 for CT/NG and Aptima Mycoplasma genitalium assays can be used to detect these three sexually transmitted pathogens in semen and in clinical specimens preserved in ESwab medium.
Disclosure No significant relationships.