Prospective Evaluation of ResistancePlus MG, a New Multiplex Quantitative PCR Assay for Detection of Mycoplasma genitalium and Macrolide Resistance

Abstract

Mycoplasma genitalium is a significant pathogen for which first-line treatment is becoming less effective due to increased resistance to macrolides. As conventional culture and antimicrobial susceptibility testing is not feasible for routine detection of this pathogen, molecular markers such as detection of mutations in the 23S rRNA gene have been described to predict resistance. Recently, a novel multiplex quantitative PCR (qPCR) assay, ResistancePlus MG, has been described for the simultaneous detection of Mycoplasma genitalium and macrolide resistance. In the current study, the clinical performance of the assay was evaluated on 1,089 consecutive urine and anogenital swab samples in symptomatic and asymptomatic male and female patients. Overall, 6.0% were positive for M. genitalium, with 63.1% having macrolide resistance-associated mutations. Compared to the laboratory-validated qPCR method targeting the 16S rRNA gene and Sanger sequencing to determine 23S rRNA mutations, the sensitivity and specificity of M. genitalium detection were 98.5% and 100% and for detection of macrolide resistance mutations were 100.0% and 96.2%, respectively. This assay offers a considerable advantage in clinical settings for M. genitalium testing by making the results of macrolide resistance and mutation analyses simultaneously available, which is increasingly important with escalating macrolide resistance.

Evaluation of the Mycoplasma genitalium Resistance Plus kit for the detection of M. genitalium and mutations associated with macrolide resistance

“…Overall, the results reported in this evaluation were in agreement with previously reported sensitivity and specificity rates for this assay10; however, we found the assay to be more sensitive for macrolide-genotype detection than Le Roy et al (2017) 11…”

Mycoplasma genitalium: high prevalence of resistance to macrolides and frequent anorectal infection in men who have sex with men in western Sydney

“…Macrolide resistance in anorectal infections has not previously been systematically investigated, but was recently detected in 7/7 (100%) anorectal samples in Melbourne, Australia 15. Selection of macrolide-resistant strains is likely among groups with high rates of partner change and frequent episodes of STI treatment.…”

Mycoplasma genitalium: the next sexually transmitted superbug?

“…For example, single nucleotide polymorphisms in region V of the 23S rRNA gene, which confer macrolide resistance, were found in over 60% of M genitalium specimens from people attending STI clinics in Australia in 2015 14. Furthermore, selective pressure can lead to the emergence of macrolide resistance after exposure to suboptimal levels of drug 15.…”