Methods: Adult Pneumonia Study Group – Japan conducted multi center prospective surveillance to evaluate disease burden and epidemiology of community onset pneumonia (≧15years or older ) in Japan from 2012 to 2015. We enrolled 3,740 community onset pneumonia cases and collected 2,616 sputum samples. Sputum samples were tested for 13 viruses and 6 bacteria including M pneumoniae by multiplex PCR assays. We performed gene sequencing of Domain V of 23s rRNA in M pneumoniaepositive DNA samples to detect macrolide resistant genes, A2063G and A2064G, when enough amount of DNA was available.
Results: Of 2,616 sputum samples, M pneumoniae P1 protein gene was positive in 88 (3.4%) cases by multiplex PCR. M pneumoniae positive patients were younger, more likely to have mild disease and more likely to be treated as outpatient. Annual incidences of M pneumoniae pneumonia among younger than 65 years and older than 65 years in 2012 were estimated to be 1/1000 person・year and 0.5 person・year, respectively. From 88 M pneumoniae positive samples, 55 samples were successfully sequenced Domain V of 23s rRNA gene and 32 cases (62.7%) were shown as positive for macrolide resistance gene. Unexpectedly, 80% of M pneumoniaewere macrolide resistant among middle aged patients.
Conclusion: Among middle aged patients with M pneumoniae pneumonia in Japan, high prevalence of macrolide resistant gene is emerging problem. Because macrolide has been considered as first choice drug to treat adult M pneumoniae pneumonia and it is sometimes self-limiting, well-designed control trials are needed to determine appropriate treatment of adult M pneumoniae pneumonia.
L. M. Yoshida, None
L. N. Minh, None
K. Ariyoshi, None