Prevalence and molecular characteristics of Mycoplasma pneumoniae in Beijing in the first half of 2015 and 2016 / 中华微生物学和免疫学杂志

ABSTRACT

Objective To investigate the prevalence and molecular characteristics of Mycoplasma pneumoniae (M.pneumoniae) in Beijing in the first half of 2015 and 2016. Methods Respiratory tract specimens were collected from children with respiratory infection who were admitted to Affiliated Children′s Hospital of Capital Institute of Pediatrics in the first half of 2015 and 2016. DNA molecules were extracted from these specimens and then analyzed by real-time PCR to detect M.pneumoniae repMp1 genes. Speci-mens that were positive for M.pneumoniae were genotyped by modified MLVA[multiple-locus variable-num-ber tandem-repeat (VNTR) analysis] and P1-RFLP (restriction fragment length polymorphism analysis). Moreover, macrolide resistance was evaluated through detecting mutations in 23S rRNA genes. Results The prevalence of M.pneumoniae from January to June in 2015 and 2016 was 18.5% (50/271) and 35% (99/283),respectively. Of the 50 strains isolated in 2015,48 were M4-5-7-2/P1 genotype and only two were M3-5-6-2/P2 genotype. The 99 strains isolated in 2016 belonged to three genotypes, including 82 of M4-5-7-2/P1,two of M4-5-7-3/P1 and 15 of M3-5-6-2/P2. Macrolide resistance rate was 92% in 2015 and 83.8% in 2016. Conclusion More cases of M.pneumoniae infection were detected in the first half of 2016 than in the corresponding period of 2015. Compared with the 2015,the proportion of M4-5-7-2/P1 genotype strains decreased,while that of M3-5-6-2/P2 genotype strains increased in 2016. Moreover, a decline in macrolide resistance rate was found in 2016.