Mycoplasma Pneumonia

To understand Mycoplasma, it's essential to contrast it with pneumococcal pneumonia.

Mycoplasma:
- Gradual onset, often sneaking up on individuals.
- Primarily affects young adults because children experience milder symptoms and transmit the infection to adults, who then develop more severe symptoms.
Pneumococcal:
- Sudden and severe onset due to toxins and the ability to evade phagocytosis.
- Can cause severe infection rapidly, leading to hospitalization with breathing difficulties.
- Patients may exhibit blue lips (cyanosis) due to lack of oxygen exchange.

Mycoplasma:
- Typically presents to a general practitioner (GP) rather than the emergency department.
- Patients feel unwell but are still mobile, often referred to as "ambulant pneumonia."
- Chest X-rays reveal widespread involvement in both lung fields with fluid throughout.
Pneumococcal:
- Patients are very ill upon arrival at the emergency department.
- May present with blue lips and signs of toxicity.
- Considered a life-threatening infection.

Mycoplasma:
- Non-productive cough or small amounts of clear or mucoid sputum, potentially with some flecks.
- Pus cells may be present due to the repair process following damage to the cilia.
Pneumococcal:
- Copious purulent (pus-filled) secretions, except in immunocompromised patients like those undergoing chemotherapy who may be neutropenic.

Mycoplasma:
- Lower temperature elevation.
- Inflammation is less severe.
Pneumococcal:
- Characterized by high temperatures.
- Can lead to pleurisy (inflammation of the lung lining), which is very painful.

Pneumococcal:
- Commonly presents with consolidation (localized areas of density) in the lungs, often affecting a lobe.
Mycoplasma:
- Diffuse interstitial inflammation, appearing as a slight, evenly spread whiteness throughout the lung fields.

Mycoplasma:
- White cell count tends to be on the upper limit of normal with a normal differential.
Pneumococcal:
- Typical bacterial infection response with a white blood cell count greater than 15,000 with a predominance of neutrophils.

Mycoplasma:
- Respiratory PCR panels are increasingly used for diagnosis, representing an improvement over serology, which can be delayed in detecting IgA antibodies.
Pneumococcal:
- Diagnosis primarily relies on Gram stain, culture, and microscopy of sputum.

Mycoplasma lack a peptidoglycan cell wall, possessing only inner and outer membranes. Therefore, they do not stain with Gram stain.
They are the smallest free-living microbes but require close proximity to a host to survive.
In humans, they are typically transmitted via respiratory secretions.
Mycoplasma are classified as low GC bacteria with a small genome, having lost much of the genetic information required for environmental survival.

Influenza can also cause atypical pneumonia, and secondary infection with Strep pneumoniae can result in pus formation.

Mycoplasma infections often present with an unproductive cough and clear mucoid material.
Common in young children, who often transmit it to their parents.
Outbreaks can occur in families, schools, and universities, and can occur year-round.

For Mycoplasma, clinicians often use empirical therapy due to the mildness of the illness in most adults.
Empirical therapy refers to treatment that is likely to work based on the clinical presentation.
Example: Gonococcal Urethritis: Cephalosporin + Azithromycin
In young adults with a chronic cough and diffuse pattern on a chest X-ray, erythromycin may be prescribed to shorten symptoms, although coughing fits can persist for months due to epithelial damage.