Macrolide and fluoroquinolone resistance-associated mutations in Mycoplasma genitalium in Johannesburg, South Africa, 2007-2014.

BACKGROUND

Antimicrobial resistance in Mycoplasma genitalium is rising globally with resultant clinical treatment failure. We investigated the prevalence of mutations in the macrolide and fluoroquinolone resistance-determining regions of M. genitalium in Johannesburg, South Africa, and ascertained their association with HIV serostatus.

METHODS

Stored M. genitalium positive specimens, collected from STI and HIV patients enrolled in the Gauteng STI National Microbiological Surveillance programme (2007-2014) and a large HIV outpatient clinic-based study (2007) in Johannesburg, were tested for antimicrobial resistance.

RESULTS

We determined the prevalence of 23S rRNA gene mutations conferring macrolide resistance and mutations in the quinolone resistance-determining regions (QRDR) of the gyrA and parC genes in 266 M. genitalium positive DNA extracts. No macrolide resistance-associated mutations were detected in any of the specimens analysed. QRDR mutations with known M. genitalium-associated fluoroquinolone resistance were not detected in gyrA, however, one specimen (0.4%) contained a D87Y amino acid alteration in parC, which has been linked to fluoroquinolone treatment failure. The most common parC amino acid change detected, of unknown clinical significance, was P62S (18.8%). We found no significant association between QRDR mutations in M. genitalium and HIV-infection.

CONCLUSIONS

Ongoing antimicrobial resistance surveillance in M. genitalium is essential, as macrolide resistance may emerge given the recent incorporation of azithromycin into the 2015 South African national STI syndromic management guidelines.