Mycoplasmas are ubiquitous bacteria that differ from other prokaryotes in that they lack a cell wall.
Mycoplasma pneumoniae is a common cause of pneumonia, particularly community-acquired pneumonia.
Increasing evidence suggests that Mycoplasma genitalium and Ureaplasma urealyticum cause some cases of nongonococcal urethritis. They (and Mycoplasma hominis) are often present in patients with other urogenital infections (eg, vaginitis, cervicitis, pyelonephritis, pelvic inflammatory disease) and some nonurogenital infections, but their role in these infections is not clear.
Diagnosis of Mycoplasmas
For M. pneumoniae, nucleic acid–based testing or detection of antibodies
For M. genitalium, nucleic acid–based testing
Culture is technically difficult and often unavailable, but laboratory diagnosis is possible with nucleic acid amplification tests (NAATs) or by detection of antibodies (for M. pneumoniae); frequently, diagnosis must be by exclusion.
There are now three NAATs available for M. pneumoniae as part of commercially available panels that test for multiple respiratory pathogens.
NAATs that detect M. genitalium are commercially available.
Mycoplasmas are not visible with light microscopy.
Treatment of Mycoplasmas
Macrolide antibiotics
Fluoroquinolones or tetracyclines
Macrolides are usually the antimicrobials of choice. Most species are also sensitive to fluoroquinolones and tetracyclines.
Macrolide resistance in M. pneumoniae has been reported in > 80% of isolates in China and Japan. Preliminary data show the prevalence of resistance may be as high as 12% in the United States (1). Therefore, fluoroquinolones or tetracyclines should be considered in patients with refractory disease, especially in areas with significant macrolide resistance.
M. genitalium has been developing widespread resistance to macrolides, tetracyclines, and fluoroquinolones, which makes treating infection with this organism a challenge.
NAATs to detect macrolide resistance in M. pneumoniae and M. genitalium are currently being developed.
Treatment reference
1. Centers for Disease Control and Prevention: M. pneumoniae infection: Antibiotic Treatment and Resistance. Accessed 03/30/2023.
More Information
The following English-language resources may be useful. Please note that THE MANUAL is not responsible for the content of these resources.
Centers for Disease Control and Prevention (CDC): 2021 Sexually Transmitted Infections Treatment Guidelines: Mycoplasma genitalium
CDC: M. pneumoniae infection: Antibiotic Treatment and Resistance
