Mycoplasma genitalium (Mgen)

M. genitalium, the hidden STI

Mycoplasma genitalium (Mgen) is a complex bacterial infection that is most commonly transmitted through direct genital-genital contact. Although often asymptomatic, this sexually transmitted infection (STI) can be responsible for causing cervicitis in females, and causes urethritis in males. The infection is responsible for approximately:

  • 15 - 20% of nongonococcal urethritis (NGU)1
  • 20 - 25% of nonchlamydial NGU1
  • 30% of persistent or recurrent urethritis1
Uncovering the consequences of Mgen

Though this organism is seemingly in its infancy, research has proven Mgen to be more dangerous than initially realized.

If left untreated, Mgen can lead to severe health complications. These include pelvic inflammatory disease (PID), adverse pregnancy outcomes such as preterm delivery and miscarriage, increased risk of HIV acquisition, sexually acquired reactive arthritis, and infertility.2-4

Mgen under a microscope
The need for accurate and efficient diagnostics

Because of its more recent emergence as an STI, most countries do not have a program in place for testing the infection status of Mgen. However, due to the growing burden of disease, rising antibiotic resistance, and three-fold risk incurred for acquiring HIV, accurate and efficient diagnostic tools and methods are critical.

Today, advancements in nucleic acid amplification testing  have made study and diagnosis of this infection possible. Mgen is a fastidious organism which requires very specific nutrients and conditions to grow. This meant that prior to the advent of NAAT, time consuming diagnostic techniques such as culture were inadequate for diagnosing the organism.

Using PCR technology, scientists have been able to discover how this enigmatic organism functions and how it can be identified and treated in the growing patient population.

What is antibiotic resistance?
Shining a light on the new antibiotic resistant STI

Antimicrobial resistance threatens the effective prevention and treatment of bacterial infections, including Mgen. The emergence of antibiotic resistance in Mgen infections has led to a decrease in successful treatment since 20095 and continued empiric use of first-line antibiotics has resulted in the widespread transmission of resistant strains of Mgen.

Prevalence of Mgen and antibiotic resistance around the world

Studies have shown that Mgen is detected in 1-3% of the general population. However, higher positivity rates have been associated in patient populations experiencing urethritis, cervicitis, endometritis and pelvic inflammatory disease (PID).6 Furthermore, single-nucleotide polymorphisms associated with macrolide antibiotic resistance is highly prevalent in many parts of the world, especially in Europe, Australia and North America, as shown in the figure below.7

MG susceptibility world heat map
Informing better treatment pathways

Drug regulations and prescription policies play a crucial part in combatting antimicrobial resistance, but clinicians need to embrace new molecular diagnostic methods to detect these challenging strains and any associated antibiotic resistance.

Resistance Guided Therapy for Mgen dramatically improves cure rates.4 Utilizing diagnostic tools to identify antimicrobial resistant strains of Mgen enables healthcare practitioners to decide on the most appropriate treatment choice.

Watch Luke's story on overcoming Mgen diagnosis and treatment challenges


  1. CDC’s Sexually Transmitted Infections (STI) Treatment Guidelines, 2021. Accessed October 2023.
  2. Soni, S. et al., 2019. International Journal of STD and AIDS. 30(10), pp. 938-950.
  3. Ona S, et al. Infect Dis Obstet Gynecol. 2016;2016:4513089.
  4. Denison, HJ., et al. 2016. Clinical Rheumatology. 35(11): 2639–2648
  5. Read TRH, et al. Clinical Infectious Disease 2019;68(4):554–560.
  6. Jensen JS. et al., J Eur Acad Dermatol Venereol, 2016;30(10):1650-1656
  7. Machalek, DA. et al, 2020. The Lancet Infectious Diseases. 10.1016/S1473-3099(20)30154-7.