Poster Presentation Australian Society for Microbiology Annual Scientific Meeting 2024

Fluoroquinolone resistance detection in Mycoplasma genitalium (#203)

Nicole G Ertl 1 , David M Whiley 1 2 , Emma L Sweeney 1
  1. The University of Queensland, Herston, QLD, Australia
  2. Pathology Queensland Central Laboratory, Brisbane, QLD, Australia

Mycoplasma genitalium is a sexually-transmitted infection with serious health impacts that due to its increasing resistance to recommended antimicrobials (e.g. macrolides, fluoroquinolones) has been placed on the CDC watch list for antimicrobial resistance (AMR) threats. While fluoroquinolone resistance varies globally (e.g. 14.3% prevalence in the Western Pacific region), resistance and associated treatment failures have been increasing. Current research has linked fluoroquinolone treatment failure to mutations in the DNA topoisomerase (parC) and DNA gyrase (gyrA) genes, with the risk of moxifloxacin or sitafloxacin failure increased when ParC-S83I and GyrA-M95/D99 mutations co-occur. We have analysed M. genitalium positive samples from patients in Queensland and showed that over half of the samples with a ParC-S83I mutation also carried a concurrent GyrA-M95I mutation, while GryA mutations were rare in ParC wildtype and non-S83I samples. In response we have developed a rapid multiplex PCR test that detects all three parC and gyrA targets using a simplistic beacon-based approach. Testing and validations are ongoing. Taken together, our local Queensland data suggests that diagnostics that incorporate information about both parC and gyrA mutations could be clinically beneficial, allowing health-care professionals to make resistance-guided treatment decisions to improve patient outcomes and aid in antimicrobial stewardship. With M. genitalium culture difficult and time intensive, our simple, real-time PCR based multiplex test can be used to directly inform optimal treatment.