Jiuxin Qu1, Shuyan Chen2, Fang Bao3, Li Gu4, Bin Cao5. 1. Department of Clinical Laboratory, The Third People's Hospital of Shenzhen, Shenzhen, Guangdong, China; Department of Infectious Diseases and Clinical Microbiology, Beijing Chao-Yang Hospital, Beijing Institute of Respiratory Medicine, Capital Medical University, Beijing, China. Electronic address: qujiuxin@163.com. 2. Department of Clinical Trial, The Third People's Hospital of Shenzhen, Shenzhen, Guangdong, China. 3. Department of Pediatrics, Beijing Chao-Yang Hospital, Beijing Institute of Respiratory Medicine, Capital Medical University, Beijing, China. 4. Department of Infectious Diseases and Clinical Microbiology, Beijing Chao-Yang Hospital, Beijing Institute of Respiratory Medicine, Capital Medical University, Beijing, China. Electronic address: guli2013227@foxmail.com. 5. Department of Respiratory and Critical Care Medicine, Clinical Microbiology and Infectious Disease Lab, China-Japan Friendship Hospital, Beijing, 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.
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.