[Survey of macrolide resistance in Mycoplasma pneumoniae in adult patients with community-acquired pneumonia in Beijing, China].

OBJECTIVE: To explore the tendency of macrolide resistance in Mycoplasma pneumoniae infection in community-acquired pneumonia (CAP) patients in Beijing.

METHODS: Adult CAP patients of ≥ 18 yrs were enrolled in 3 medical centers in Beijing , China. Throat swab samples were taken from all the patients to perform the culture of M. pneumoniae . All the isolated M. pneumoniae strains were subjected to susceptibility evaluation for 6 agents, including macrolides such as erythromycin and azithromycin. In strains showing macrolide resistance, the 23S rRNA gene was analyzed.

RESULTS: A total 53 strains of M. pneumoniae were isolated from 321 enrolled patients. Thirty-eight of the isolated strains (71.7%) were resistant to erythromycin and 32 of them (60.4%) were resistant to azithromycin. Six strains with moderate or low level of erythromycin-resistance were still susceptible to azithromycin. No fluoroquinolone-resistant or tetracycline-resistant strains were observed in our study. Point transition of A2063G in the 23S ribosomal RNA gene was the main reason for the high prevalence of macrolide resistance.

CONCLUSIONS: The prevalence of macrolide resistance in M. pneumoniae is very high in adult CAP patients in Beijing. Studies are needed to clarify the clinical meaning of prevalence of macrolide-resistant M. pneumoniae in adults CAP patients.