Single-Locus-Sequence-Based Typing of the mgpB Gene Reveals Transmission Dynamics in Mycoplasma genitalium

Abstract

Sexually transmitted infections (STIs) by Mycoplasma genitalium are a major problem worldwide, especially given their marked and rapid propensity for developing antimicrobial resistance. Since very few treatment options exist, clinicians face an important challenge in the management of the infection. In this scenario, little is known regarding the transmission dynamics of M. genitalium and the epidemiology of antimicrobial resistance. This mgpB-based molecular typing study, conducted among 54 asymptomatically infected individuals prospectively recruited from an STI screening service, reveals two distinct epidemiological clusters that significantly correlate with sexual conduct in heterosexuals and men who have sex with men (MSM), respectively. This well-defined structuration suggests the presence of two independent sexual networks with little connectivity between them. On the other hand, the study demonstrates the multiclonal feature of the emergence of antibiotic resistance in M. genitalium to both macrolides and fluoroquinolones. The high prevalence of macrolide resistance in M. genitalium among MSM, influenced by dense network connectivity and strong antibiotic selective pressure, may correspond to allodemics affecting other STIs such as gonorrhea, syphilis and enteric pathogens. Collaterally, the structural and functional impact of mutations in the mgpB gene, encoding the major adhesin P140 (MgpB), may require further investigation.

Antibiotic Resistance and Genotypes of Mycoplasma genitalium during a Resistance-Guided Treatment Regime in a German University Hospital

“…Despite the low rate of non-MSM with a confirmed mgpB type among the patients ( n = 8, 13.8%), one of two women who have sex with men (WSM) and the men who have sex with women (MSW) belonged to cluster 2 (exception: woman #35), supporting the hypothesis of a largely independent circulation of genotypes in both groups. This was also shown in a recent study [ 27 ]. After the investigation of strains sampled between the years 2014 and 2016 in Dresden (31.6%) and between 2017 and 2018 in Berlin (38.6%), type 4 was also the most common mgpB type [ 21 , 28 ].…”

“…After the investigation of strains sampled between the years 2014 and 2016 in Dresden (31.6%) and between 2017 and 2018 in Berlin (38.6%), type 4 was also the most common mgpB type [ 21 , 28 ]. Furthermore, the results of reports from France and Spain demonstrated rates of type 4 strains of 23.8% and 27.8%, respectively [ 20 , 27 ]. All these studies included a high percentage of MSM.…”

“…In combination with a high rate of the prescription of macrolides among (HIV-positive) MSM, the genotypes in this specific group tend to demonstrate a higher rate of resistance to azithromycin. At this stage, it remains unclear if the predominance of mgpB type 4 among MSM is the result of easier transmission during anal intercourse [ 20 ] or of the limited connectivity between the sexual networks of MSM and WSM/MSW [ 27 ].…”

Prevalence of Mycoplasma genitalium fluoroquinolone-resistance markers, and dual-class-resistance markers, in asymptomatic men who have sex with men

“…This suggests that transmission is not the sole cause of antibiotic-resistance spread in this study group; rather, parC SNPs have likely arisen independently during fluoroquinolone treatment. Similar findings were reported in studies by Fernandez-Huerta et al (2020) andSweeney et al (2020) where they both observed de novo acquisition of parC mutations[47,48]. Insufficient information was available to analyse the distribution of gyrA SNPs.The most common STs observed in this study were ST-A/105 and ST-C/4.…”

Integrating the Human and Animal Sides of Mycoplasmas Resistance to Antimicrobials

“…In several studies, a large distribution of M. genitalium genotypes was found among macrolide-and fluoroquinolone-resistant isolates, supporting the hypothesis of a multiclonal spread of resistance in this species, rather than the spread of a single or of a few resistant clones. This multiclonal spread is likely associated with the consequences of antibiotic selection pressure on diverse independent M. genitalium strains [161][162][163].…”