🦠 Mycoplasmas are the smallest free-living microorganisms, lacking a cell wall but capable of replicating independently. Most are harmless, but some cause important respiratory and urogenital infections. Understanding their features, key pathogens, and treatment is crucial for effective management.

📖 About

🧬 Characteristics: Smallest free-living organisms, no cell wall, replicate independently outside host cells.
⚠️ Pathogenicity: Most harmless; pathogenic species cause local mucosal damage or autoimmune phenomena.
🤒 Diseases: Pneumonia, urethritis, pelvic inflammatory disease (PID).

🧫 Pathogenic Mycoplasmas

🌬️ Mycoplasma pneumoniae:
- URTI spread by coughs; incubation 2–3 weeks.
- Common in ages 5–20 yrs → causes “atypical pneumonia.”
- IgM against RBC "I" antigen → haemolysis & positive Coombs test.
- ⛔ Rarely life-threatening, but may cause complications:
  - ENT: bullous myringitis 👂
  - Skin: erythema multiforme, Stevens-Johnson 🌸
  - Neuro: aseptic meningitis, transverse myelitis, GBS 🧠
  - Other: Raynaud’s, carotid occlusion, stroke, polyarthralgia.
👩‍🦰 Mycoplasma hominis: Vaginitis & PID (erythromycin-resistant).
🧑‍❤️‍🧑 Mycoplasma genitalium: Urethritis & PID.
💧 Ureaplasma urealyticum: Hydrolyses urea → causes urethritis.
⚡ Mycoplasma fermentans: Can cause overwhelming infections in immunocompromised hosts.

🔎 Investigations

🩸 Cold agglutinins: RBC clumping at 4°C (seen in Mycoplasma, EBV, CMV, lymphomas).
🧬 PCR: Highly sensitive for Mycoplasma DNA detection.
🧪 Serology: Detects species-specific antibodies.
🧫 Culture: Rarely used; slow & difficult.

💊 Management

🚫 Resistance: No cell wall → resistant to β-lactams (penicillins, cephalosporins).
✅ Effective antibiotics:
- Macrolides: azithromycin, erythromycin.
- Tetracyclines: doxycycline, tetracycline (avoid in pregnancy & <8 yrs).
⚠️ Note: Erythromycin may ↑ theophylline levels → toxicity risk.
📅 Duration: 7–14 days depending on severity.
🛌 Supportive care: Rest, hydration, antipyretics.
🧼 Prevention: Hygiene & avoiding close contact with infected individuals.
🧠 Complications: Treat systemic/autoimmune effects individually (e.g., GBS, encephalitis).

📌 Conclusion

While many Mycoplasma infections are mild, they can trigger serious systemic complications in children, young adults, and immunocompromised patients. Accurate diagnosis with PCR/serology and appropriate antibiotic therapy are essential. Prevention through hygiene and awareness remains key.

📚 References

Glenney JA, Fox JG, Moore MR. Mycoplasma Infections in Clinical Practice. Springer, 2005.
Mayo Clinic. Mycoplasma Infections. Link
NIH. Mycoplasma Infections. Link
WHO. Antibiotic Resistance. Link
CDC. Mycoplasma pneumoniae. Link

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Mycoplasmas