Use of the mtrR Gene for Rapid Molecular Diagnosis of Neisseria gonorrhoeae and Identification of the Reduction of Susceptibility to Antibiotics in Endocervical Swabs.

BACKGROUND: Neisseria gonorrhoeae is one of the main etiological agents of sexually transmitted diseases. The asymptomatic course of the infection and its resistance to antibiotics can lead to pelvic inflammatory disease and infertility.
OBJECTIVES: We developed a polymerase chain reaction (PCR) test using the methyltetrahydrofolate homocysteine methyltransferase reductase (mtrR) gene to identify N. gonorrhoeae and detect reduced susceptibility to antibiotics.
MATERIAL AND METHODS: We analysed 250 samples of endocervical exudate from infertile women with a negative diagnosis of N. gonorrhoeae. We designed NGmtr primers to detect N. gonorrhoeae and identify the antibiotic-resistant strain.
RESULTS: Of the 250 samples, 60 (24%) tested positive for N. gonorrhoeae using real-time PCR. Our study was validated using the HO primers and the Seeplex STD6 ACE System, with a 100% correlation. Furthermore, the NGmtr primers are specific for N. gonorrhoeae and not for other species. Additionally, the curves generated by real-time PCR differed between wild and variant strains (10.93%). The dissociation temperatures for the wild and variant strains were 86.5 and 89 °C, respectively.
CONCLUSIONS: The NGmtr primers enabled us to identify N. gonorrhoeae strains with or without reduction of susceptibility to antibiotics. Therefore, this work constitutes a tool that will facilitate the diagnosis of this infection for a low cost and improve patient quality of life.