Macrolide-Resistant Mycoplasma pneumoniae in Adults in Zhejiang, China

Abstract

ABSTRACTMycoplasma pneumoniaeis a major pathogen causing community-acquired pneumoniae (CAP), which is generally treated with macrolides. In recent years, however, although macrolide-resistantM. pneumoniaehas been reported frequently, particularly in China, very little is known about the prevalence of macrolide-resistantM. pneumoniaeinfection in adults. In this study, we survey the macrolide-resistantM. pneumoniaein adults in Zhejiang province and characterize the mechanisms of resistance to macrolide. Six hundred fifty throat swab samples were collected from adult patients with CAP from January 2012 to August 2014. These samples were assayed by nested PCR and then cultivated forM. pneumoniae. All isolates were sequenced to determine the mutation in domain V of the 23S rRNA gene. The activities of 10 antibiotics against macrolide-resistantM. pneumoniaeisolates were also investigatedin vitro. Moreover, restriction fragment length polymorphism (RFLP) analysis of the amplified P1 gene was used to type 50 resistant strains. One hundred percent (71/71) ofM. pneumoniaestrains isolated from adults with CAP were resistant to erythromycin (MIC = 128 to >256 μg/ml), clarithromycin (MIC = 128 to >256 μg/ml), and azithromycin (MIC = 32 to >64 μg/ml). Furthermore, all macrolide-resistantM. pneumoniaestrains identified had an A2063G mutation in domain V of the 23S rRNA gene. Forty-six resistant strains (92.0%) were classified into type I strain on the basis of P1 gene PCR-RFLP analysis. According to these findings, it is suggested that macrolide-resistantM. pneumoniaeinfection is very prevalence among adults in Zhejiang province. Thus, there is necessary to perform the epidemiological monitoring of macrolide-resistantM. pneumoniaein the future.