ResistancePlus® MG

Unlocking resistance guided therapy for Mycoplasma genitalium

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Unlocking resistance guided therapy for Mycoplasma genitalium

The overuse and misuse of antimicrobials is complicating the treatment of previously manageable diseases.

In the case of Mycoplasma genitalium (Mgen) infections, the increased use of macrolide-based antibiotics to treat infections has impacted the drug’s effectiveness to treat Mgen.1 Detecting macrolide resistance can reduce the time to cure and prevent ongoing transmission.2

Through a partnership with SpeeDx, a developer of innovative molecular diagnostic solutions, Roche is ushering in a new era of resistance-focused diagnostics.

ResistancePlus® MG, powered by proprietary PlexPCR® technology, is a multiplex real-time PCR assay for the identification of Mycoplasma genitalium and the detection of 5 macrolide resistance markers associated with resistance to azithromycin. Putting the right information in the right hands is essential to optimizing antimicrobial use and ensuring patients get the best care possible.

About the assay

ResistancePlus® MG aids healthcare professionals in prescribing appropriate treatment based on the resistance status of a patient’s Mgen infection. This paves the pathway forward for resistance-guided therapy and supports current and emerging international guideline recommendations.

close up of pipet
Assay design

Leveraging the flexible PlexPrime® design allows for increased specificity and reduced competition while distinctly different amplicons aid in allele-specific detection in multiplexed format.

ResistancePlus® MG is a multiplex qPCR test for detection of Mycoplasma genitalium and five azithromycin resistance markers, validated for a range of specimen types.

 targeting sequences inside a Neisseria gonorrhea bacterium
Multiplexing capability

Proprietary PlexPCR® technology enables the simultaneous detection of Mgen and five azithromycin resistance markers in a single well.

Channel and target table, MG
High specificity

ResistancePlus® MG has clinical data from over 1000 samples, with the data demonstrating excellent sensitivity and specificity.

ResistancePlus® MG sensitivity and specificity performance diagram
Improving patient management with resistance-guided therapy

Knowing the resistance status of Mgen infections prior to treatment can be crucial in deciding on the most effective treatment, as antibiotic resistance can lead to cure rates as low as 40%.8 However, using resistance-guided therapy to stratify patient populations and guide appropriate treatment choices has been shown to increase cure rates from below 67% to 95% for macrolide susceptible population.7

Resistance Guided Therapy cure rates diagram
ResistancePlus® MG features and benefits

Improved cure rates: Enables resistance-guided therapy which has been clinically demonstrated to improve cure rates and reduce time to cure7

Meeting guideline recommendations:  Meets European and British guidelines for Mgen testing9,10

Quick turnaround times: From sample to result, ResistancePlus® MG delivers results in less than 3.5 hours

Platform compatibility: Validated to work on a number of extraction platforms, with amplification/detection on the LightCycler® 480 Instrument II and in the future, on the cobas z 480 Analyzer

PlexPCR® Technology

PlexZyme® technology offers high performance and reliable qPCR detection.

During PlexPCR®, primers amplify target nucleic acid sequences and produce amplicons, which serve as a template for PlexZyme® formation. Once the partzymes have assembled into PlexZyme® enzymes, universal probes bind and enzymatic cleavage of the probes between fluorophore and quencher dye pairs generates fluorescence. Changes in fluorescence allow detection and/or quantification of the target nucleic acid in real time.

PlexPrime® is a novel method for nucleic acid amplification that creates amplicons, which are distinctly different from the parent sequence. The combination of PlexPrime® and PlexZyme® technology enables multiplex mutation detection with high sensitivity and specificity.11

Intended use

The ResistancePlus® MG kit is a qualitative multiplexed in vitro diagnostic real-time PCR test for the identification  of Mycoplasma genitalium and detection of 5 mutations in the 23S rRNA gene A2058G, A2059G, A2058T, A2058C, and A2059C (Escherichia coli numbering) that are associated with resistance to azithromycin (macrolide antibiotic). It is intended to aid in the diagnosis of M. genitalium and detects mutations associated with azithromycin resistance in M. genitalium and should be used in conjunction with clinical and other laboratory information.

Registration status: CE-IVD, not available in the US


1. Unemo M, Jensen, JS. Nature Reviews Urology. 2017;14(3):139-152.

2. Couldwell DL, et al. Sexually Transmitted Infections 2018;0:1–5.

3. ResistancePlus® MG Instructions for use; IF-IV0003 v10 (March 2020).

4. Bradshaw CS, et al. PlosOne 2008;3(11): e3618.

5. Bissessor M, et al. Clinical Infectious Disease. 2015;60(8):1228-36.

6. Read TRH, et al. Clinical Infectious Disease. 2016;64(3):250-256.

7. Read TRH, et al. Clinical Infectious Disease. 2019;68(4):554–560.

8. Manhart LE, et al. Clinical Infectious Disease. 2013;56(7):934–942.

9. Jensen, J. et al., 2016. European Academy of Dermatology Venereology, 30: 1650-1656.

10. Soni, S. et al., 2019. International Journal of STD and AIDS, 30(10), pp. 938-950.

11. Tan LY, et al. PLoS One. 2017;12(1):e0170087.

ResistancePlus® MG kits are developed and manufactured by SpeeDx Pty Ltd, Sydney and distributed by Roche.

LIGHTCYCLER and COBAS Z are trademarks of Roche.

PlexPCR®, PlexZyme®, PlexPrime®, and ResistancePlus® are trademarks of SpeeDx Pty Ltd.