Mycoplasma pneumoniae causes community-acquired pneumonia and upper respiratory illness.
Infection is often seen in close community settings, such as schools, army bases, colleges, nursing homes, and hospitals.
Diagnosis of infection is usually made clinically; nucleic acid amplification tests (e.g., polymerase chain reaction), culture, or serology are required in hospitalized patients and those with severe disease to confirm M pneumoniae as the infecting pathogen. Limitations of serology include the possibility of false-positive results.
A macrolide or tetracycline antibiotic is usually effective as first-line treatment of mycoplasma infections in both uncomplicated and more severe community-acquired pneumonia.
Fluoroquinolones may be effective as second-line treatment if previous antibiotics fail.
Mycoplasma are a group of bacteria, some of which are pathogenic in humans and animals. They are the smallest free-living organisms, both in size and number of genes, and, unlike many other bacteria, they do not have a cell wall. M pneumoniae is the main human pathogen species of this group and causes respiratory infections including upper respiratory tract infection, acute bronchitis, and community-acquired pneumonia. Other pathogenic Mycoplasma species include M genitalium, Ureaplasma species (including U parvum and U urealyticum), and M hominis, which are both commensals and pathogens of the genitourinary tract. Rarely, other species, including M amphoriforme, M fermentans, M penetrans, M pirum, and M faucium, or zoonotic hemotrophic mycoplasmas have been associated with human disease, but the pathogenicity of these is still unknown.
Only confirmed infection with M pneumoniae is within scope of this topic. For more information on the general approach to community- or hospital-acquired pneumonia, including severity scoring and empirical treatment, please see Community-acquired pneumonia (non Covid-19) and Hospital-acquired pneumonia.
Please see Acute bronchitis for more information on management of this condition.
Please see Urethritis, Acute epididymitis, Cervicitis, and Pelvic inflammatory disease for more information on genitourinary infection caused by M genitalium.
History and exam
Key diagnostic factors
- persistent cough
- dry cough
- prolonged symptoms
- adventitious sounds on physical exam
- exposure to a person with respiratory tract infection
Other diagnostic factors
- throat involvement
- bullous myringitis
- close community settings
- recent exposure
- cigarette smoking
- age <30 years
1st investigations to order
- WBC count
- pulse oximetry
- BUN and electrolytes
- C-reactive protein
- chest x-ray
Investigations to consider
- nucleic acid amplification test (NAAT)
- culture±/Gram stain
- antigen test
Ran Nir-Paz, MD
Professor in Medicine and Clinical Microbiology
Department of Clinical Microbiology and Infectious Diseases
Hadassah-Hebrew University Medical Center
RNP declares that he has no competing interests. RNP is an author of several references cited in this topic.
Takeshi Saraya, MD, PhD
Department of Respiratory Medicine
Kyorin University School of Medicine
TS declares that he has no competing interests.
Enno Jacobs, MD
Institute for Medical Microbiology and Hygiene
EJ declares that he has no competing interests.
Laura J. Christie, MD
Pediatric Infectious Disease
California Department of Public Health
Viral and Rickettsial Disease Laboratory
LC declares that she has no competing interests.
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