<prompt> MC cause of atypical pneumonia?Mycoplasma pneumoniaeKlebsiella pneumoniaeHemophilus influenzaeChylamydia  <response>: MC cause of Atypical pneumonia- Mycoplasma Pneumoniae aka Eatons agent. This organism does not have cell wall which makes them resistant to the treatment by Penicillins. The infection will be treated by the use of Macrolide antibiotic Azithromycin. 