Mycoplasma pneumonia is most common among which population, and what class of antibiotics is typically used?

• A. College-age adults; Macrolides or doxycycline
• B. Infants; Penicillin
• C. Elderly; Cephalosporins
• D. Immunocompromised; Aminoglycosides

Answer: (A)

Mycoplasma pneumoniae typically causes pneumonia in young, closely living populations such as college-age adults, where dorm living and social contact facilitate transmission. The organism lacks a cell wall, so antibiotics that target cell wall synthesis, like penicillins or cephalosporins, are ineffective. Treatment, therefore, uses antibiotics that inhibit protein synthesis or other non–cell-wall targets. The usual choices are macrolides (for example, azithromycin or clarithromycin) or doxycycline. Macrolides bind the 50S ribosomal subunit to block translocation, while doxycycline binds the 30S subunit to prevent tRNA from pairing with the ribosome; both stop bacterial growth and are effective against Mycoplasma.