(P250) Antimicrobial resistance in Mycoplasma genitalium: preliminary results of the first Brazilian study

Background: Mycoplasma genitalium (MG) is an emerging sexually transmitted infection causing urethritis in men and is associated with cervicitis, preterm birth, spontaneous abortion, pelvic inflammatory disease, and infertility in women, with global concerns due to the development of antimicrobial resistance and rising incidence. In Brazil, there is a lack of information about antimicrobial resistance in MG. The aim of this study was to provide the first national results regarding MG resistance for macrolides and fluoroquinolones.

Methods: MG positive specimens were collected during 2018-2022 from male urethral discharge and pregnant women’s vaginal swabs belonging to Brazilian national STI studies. To determine macrolide and fluoroquinolone resistance-associated mutations, it was searched for possible SNPs using PCR and sequencing of 23S rRNA, parC and gyrA.

Results: Up to now, 50 MG positive specimens from all major Brazilian regions have been processed, with successful sequencing in 41 for 23S rRNA, 36 for parC and 42 for gyrA genes. Mutations associated with macrolide resistance at positions 2058 and 2059 (E. coli numbering) were detected in 53.7% (22/41) specimens, being A2059G mutation was the most common (11/22), followed by A2058G (9/22) and A2058T (2/22). Macrolide resistance-associated mutations were observed in all Brazilian regions: South region (9/14), Southeast (6/11), Northeast (4/9), Center-West (2/3), and North (1/4). Three specimens had one of these SNPs in parC gene: G248A, G259T or G259A (M. genitalium numbering), causing a missense mutation. Interestingly, one specimen of the Southeast region possesses mutation in both 23S rRNA (A2058G) and in parC gene (G259T). No SNPs were observed in the gyrA gene.

Conclusion: This unprecedented nationwide data showed more than 50% of specimens with macrolide resistance-associated mutations. This may be due to the transmission of resistance or drug pressure by widespread syndromic use of azithromycin 1g single oral dose. These results can support national epidemiological data, and the clinical practices guidelines for MG infections.