Drug of choice for Mycoplasma pneumoniae is
**Core Concept**
Mycoplasma pneumoniae is a type of atypical bacteria that causes respiratory infections, including pneumonia. The drug of choice for treating M. pneumoniae infections is typically a macrolide antibiotic.
**Why the Correct Answer is Right**
Macrolide antibiotics, such as azithromycin, work by inhibiting protein synthesis in the bacterial cell. They bind to the 50S subunit of the bacterial ribosome, preventing the formation of peptide bonds between amino acids. This ultimately leads to the death of the bacterial cell. Azithromycin is particularly effective against M. pneumoniae due to its ability to penetrate into the cells where the bacteria reside.
**Why Each Wrong Option is Incorrect**
**Option A:** Clarithromycin is also a macrolide antibiotic, but it is not the first-line treatment for M. pneumoniae infections.
**Option B:** Ciprofloxacin is a fluoroquinolone antibiotic that is effective against a wide range of bacterial infections, but it is not the preferred treatment for M. pneumoniae.
**Option C:** Doxycycline is a tetracycline antibiotic that is effective against many bacterial infections, but it is not the first-line treatment for M. pneumoniae due to its potential side effects and interactions.
**Clinical Pearl / High-Yield Fact**
Macrolide antibiotics, such as azithromycin, are often used to treat atypical bacterial infections, including Legionella pneumonia and Chlamydophila pneumoniae.
**Correct Answer:** C. Azithromycin