High prevalence of resistance to macrolides and fluoroquinolones in Mycoplasma genitalium isolated from patients in two Russian megalopolises – Moscow and St. Petersburg in 2021– 2024
Authors: Edelstein Inna A. , Gushchin A.E. , Gladin D.P. , Romanov Andrey V. , Negasheva E.S. , Frigo N.V. , Kozlov Roman S. , Potekaev N.N. , Kozlova N.S. , Borukhovich D.G. 
Published: January 2025

Objective.
To determine spectrum and prevalence of genetic determinants of macrolide and fluoroquinolone resistance in Mycoplasma genitalium from patient in dermatovenerology clinics of two Russian megalopolises: Moscow and St. Petersburg in 2021–2024.

Materials and Methods.
A total of 530 M. genitalium DNA-positive specimens (urethral and cervical swabs) obtained from men and women from the STD clinic in St. Petersburg and Сlinical facilities of the Moscow Scientific and Practical Center for Dermatovenerology and Cosmetology of the Moscow Department of Health Care were analyzed. Screening in local laboratories was performed using commercially available kits for isolation and detection of M. genitalium DNA. Primary screening for resistance-associated mutations was carried out using the previously developed protocol of PCR-RT (allows detecting any nucleotide substitutions in the 23S rRNA gene and parC gene) [1]. The results were confirmed using Sanger sequencing [2]. The study results are presented as an open project on the AMRcloud platform (https://amrcloud.net/ru/project/demares/).

Results.
185 and 345 M. genitalium-positive samples from St. Petersburg and Moscow, respectively, showed the presence of a specific signal in both the 23S rRNA gene and parC gene in primary screening. The macrolide-resistance mutations was in 29% (54⁄185) of samples from St. Petersburg and in 28% (97⁄345) from Moscow, with a predominance of the A2059G 23S rRNA genotype of M. genitalium in 57% (31⁄54) and 68% (66⁄97), respectively. The second largest proportion were samples in which the nucleotide substitution A→G at position 2058 was detected: 23⁄54 (42%) from St. Petersburg and 30⁄97 (30%) from Moscow. Mutations to fluoroquinolones were detected in the parC gene in 47⁄185 (25%) and 73⁄345 (21%) samples from St. Petersburg and Moscow, respectively. In Moscow, the amino acid substitution S80I prevails 39% (29⁄73), the second most abundant D84N occured in 35% (26⁄73), in St. Petersburg, the similar ratio of S80I was 44% (21⁄47), D84N was 29% (14⁄47). In Moscow, seven samples carried the third most common mutation S80N, which is 9%, in St. Petersburg this figure, was twice as high – 19% (9⁄47). The share of other mutations in the two cities was not more than 1% (D84G, D84Y and S81P). In St. Petersburg, simultaneously with mutations in 23S rRNA, the presence of amino acid substitutions in the ParC QRDR was also confirmed, which represented a case of combined resistance to both groups antibiotics; this level was 1.5 times higher than in Moscow (40% (39⁄97)) and amounted to 61% (33⁄54). The most common combination of mutations was A2059G (23S rRNA) + S80I (parC), which made up to 33% (18⁄54) in St. Petersburg and 25.7% (25⁄97) in Moscow. The second most abundant genotype – A2058G (23S rRNA) + D84N (parC) accounted for 14% (8⁄54) and 10% (10⁄97), respectively.

Conclusions.
The high level of resistance to macrolides and fluoroquinolones in M. genitalium in two major Russian cities is a significant problem and need for comprehensive resistance testing before prescribing therapy and surveillance programs. The introduction of adapted diagnostic and therapeutic algorithms will reduce the duration of drug administration, increase the effectiveness of therapy and reduce the burden on the health care system. The use of long-term monitoring will improve the policy of antibiotic prescription and reduce the growth of antimicrobial resistance and its spread in Russia.