Hospital, Chinese Academy of Medical Sciences, and 4Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China

The resistance rate of 67 Mycoplasma pneumoniae isolates from 356 ambulatory adult patients with respiratory tract infection was 69 % (46 of 67). All 46 macrolide-resistant strains harbored point mutations in the 23S ribosomal RNA gene. Patients infected with macrolide-resistant M. pneumo-niae required significantly longer durations of antibiotic therapy and had longer time to resolution of fever. Mycoplasma pneumoniae is a common cause of community-acquired pneumonia (CAP), especially in children and young adults, accounting for 10%–30 % of cases [1–4]. In a 2009 Chi-nese report of adult patients with CAP, M. pneumoniae was the most prevalent pathogen, accounting for 20.7 % of CAP cases [5]. Macrolides are the drugs of primary choice for the treat-ment of these infections [1], although emergence of macrolide-resistant M pneumoniae is now being reported in children [6