Molecular characterization and analysis of Mycoplasma pneumoniae among patients of all ages with community-acquired pneumonia during an epidemic in China

Abstract

Background: Analysis of the molecular characteristics of isolates is very important for clinical and epidemiological study of community-acquired pneumonia (CAP) caused by Mycoplasma pneumoniae.

Methods: Between 2010 and 2012, an epidemic period, M. pneumoniae was isolated from oropharyngeal swabs of consecutive CAP patients. Minimum inhibitory concentrations of macrolides, 23S rRNA gene sequencing, P1 gene and multilocus variable-number tandem-repeat analysis (MLVA) genotyping was conducted.

Results: 88.3% (181/205) of the isolates were macrolide-resistant M. pneumoniae (MRMP) and all harbored an A2063 G mutation. The strains were clustered into 7 MLVA types, and P1 type 1 and type 2 lineages were co-circulated (86.3% and 13.7%). Compared with adults, no specific MLVA type contributed to higher M. pneumoniae infection in children (p = 0.14). Similar macrolide profile and genotypes of M. pneumoniae was found between outpatients and inpatients. Significant differences in proportion of P1 types and two main MLVA types 4/5/7/2 and 3/5/6/2 were observed between MRMP and macrolide-sensitive M. pneumoniae (MSMP) (p < 0.001).

Conclusions: This study demonstrates a comprehensive profile of M. pneumoniae molecular characterization among CAP patients of all age, and provides more evidences on a correlation between MLVA type 4/5/7/2 and macrolide resistance in the setting of high incidence of MRMP.

Keywords: Community-acquired pneumonia; MLVA; Macrolide resistance; Mycoplasma pneumoniae; P1 genotype.