Adult community-acquired pneumonia caused by macrolide resistant Mycoplasma pneumoniae.

A 28-year-old woman with community-acquired pneumonia was treated with sulbactam/ampicillin and clarithromycin, but failed to show any improvement after 4 days. The antibiotic regimen was changed to pazufloxacin and rapid clinical improvement was seen. Mycoplasma pneumoniae was identified as the causative agent, and adenine (A) to guanine (G) mutation at position 2063 in domain V of the 23S rRNA was noted in the isolate. The minimum inhibitory concentration of macrolide antibiotics, including clarithromycin, of this isolate was greatly elevated.