EXECUTIVE SUMMARY

Mycoplasma genitalium, a sexually transmitted infection, is a major cause of urethritis in men and is associated with cervicitis, pelvic inflammatory disease, preterm birth, and spontaneous abortion in women.

  • Recent research indicates failure rates following azithromycin treatment have increased due to the emergence of worldwide macrolide antimicrobial resistance against the infection.
  • Nucleic acid amplification testing is used, and diagnosis can be made through testing of urine, urethral, vaginal, and cervical swabs and through endometrial biopsies. However, these types of tests are only available in some large medical centers and commercial laboratories.

Mycoplasma genitalium (MG), a sexually transmitted infection, is a major cause of urethritis in men and is associated with cervicitis, pelvic inflammatory disease, preterm birth, and spontaneous abortion in women. Recent research indicates failure rates following azithromycin treatment have increased due to the emergence of worldwide macrolide antimicrobial resistance of the infection.1

Researchers at the University of Bristol’s Population Health Sciences recently published a meta-analysis intended to determine rates of MG treatment failure and resistance with different azithromycin treatment regimens.2 What spurred scientists to look at this subject?

Publishing this meta-analysis is important now because it quantifies for the first time the risk (12%) of developing macrolide resistance in patients with MG when treated with 1 gram of azithromycin, the first-line global treatment for the infection, says Paddy Horner, MD, a consultant senior lecturer at the University of Bristol and lead author of the research paper.

“What’s more, given the rapid increase in drug-resistant MG, we don’t have the time to wait for the results of randomized controlled trials, which could take up to seven years,” says Horner. “In response to this meta-analysis, the online version of the UK NGU [nongonococcal urethritis] guidelines (https://www.bashh.org/guidelines) have been updated, bringing them into line with the 2016 European NGU guidelines.”

Get Up to Speed

First identified in 1980, Myco-plasma genitalium is a bacterium that can infect the reproductive tract and is passed through sexual contact. Infection in men can cause urethritis; in women, infection has been linked to cervicitis, pelvic inflammatory disease, and infertility.3

According to the Centers for Disease Control and Prevention’s (CDC) 2015 guidelines, MG is responsible for approximately 15-20% of nongonococcal urethritis cases, 20-25% of nonchlamydial NGU, and approximately 30% of persistent or recurrent urethritis.4 In most settings, it is more common than Neisseria gonorrhoeae but is less common than Chlamydia trachomatis.

Mycoplasma genitalium is an organism that grows slowly; its culture can take up to six months, and there are only a few laboratories in the world that are able to recover clinical isolates. Public health officials now look to nucleic acid amplification testing (NAAT) for testing. Diagnosis can be made through NAAT of urine, urethral, vaginal, and cervical swabs, and through endometrial biopsies. These types of tests are only available in some large medical centers and commercial laboratories. At the present time, there is no diagnostic test for M. genitalium that is cleared by the Food and Drug Administration. The genetic makeup of the bacteria leads to development of antibiotic resistance; rates of resistance are high, making treatment challenging.

What Is the Public Health Response?

In 2016, a National Institutes of Allergy and Infectious Diseases-funded Technical Consultation brought together researchers to review current knowledge and concerns about Mycoplasma genitalium. A recent supplement of the Journal of Infectious Diseases summarizes what is known about its pathogenesis, diagnostic assays, treatment and antimicrobial resistance, and criteria for developing public health control programs.6

“We reached a tipping point in our research on M. genitalium where there was finally enough data to figure out if we needed a public health response,” said Lisa Manhart, MPH, PhD, a professor in the Departments of Epidemiology and Global Health at the University of Washington, in a press statement accompanying the publication. “The goal of the consultation was to review the evidence and make some recommendations about whether a national control program in the U.S. was appropriate.”

More than 50 researchers from academia, the CDC, and the diagnostics and pharmaceutical industries took part in the technical consultation and development of the consensus recommendations. They determined four main consensus recommendations for future research:

  • Clinical trials are needed to determine whether to recommend widespread screening for asymptomatic M. genitalium and treatment to improve reproductive health in women.
  • More effective antibiotics are needed for infections, given the widespread antibiotic resistance of M. genitalium.
  • Diagnostic tests designed to include the detection of resistance genes to a spectrum of antibiotic drug classes must be developed and made broadly available.
  • More research is necessary to identify new antibiotic targets and potential vaccine targets, and to gain an understanding of the life cycle of M. genitalium in reproductive tract tissues.6 

REFERENCES

  1. Murray GL, Bradshaw CS, Bissessor M, et al. Increasing macrolide and fluoroquinolone resistance in Mycoplasma genitalium. Emerg Infect Dis 2017;23:809-812.
  2. Horner P, Ingle SM, Garrett F, et al. Which azithromycin regimen should be used for treating Mycoplasma genitalium? A meta-analysis. Sex Transm Infect 2017; doi: 10.1136/sextrans-2016-053060.
  3. Lis R, Rowhani-Rahbar A, Manhart LE. Mycoplasma genitalium infection and female reproductive tract disease: A meta-analysis. Clin Infect Dis 2015;61:418-426.
  4. CDC. Sexually transmitted diseases treatment guidelines, 2015. MMWR Recomm Rep 2015;64:1-137.
  5. Taylor-Robinson D, Jensen JS. Mycoplasma genitalium: From chrysalis to multicolored butterfly. Clin Microbiol Rev 2011;24:498-514.
  6. Martin DH, Manhart LE, Workowski KA. Mycoplasma genitalium: From basic science to public health: Summary of the results from a National Institute of Allergy and Infectious Diseases technical consultation and consensus recommendations for future research priorities. J Infect Dis 2017;216(Suppl 2):S427-S430.