Related Experiment Video
Updated: Dec 20, 2025
Constructing Mutants in Serotype 1 Streptococcus pneumoniae strain 519/43
Published on: September 11, 2020
Molecular characterization of Streptococcus pneumoniae isolated from pediatric patients in Shanghai, China
Xing Wang1, Zhilei Cong2, Weichun Huang1
1Department of Laboratory Medicine, Shanghai Children's Medical Center, Shanghai Jiaotong University School of Medicine, Shanghai, China.
Insights
Molecular characterization of Streptococcus pneumoniae in Shanghai revealed serotype 19F dominance and high macrolide resistance. The 7-valent pneumococcal conjugate vaccine shows limited coverage, necessitating updated immunization strategies.
Area of Science:
- Microbiology
- Infectious Diseases
- Pediatrics
Background:
- Streptococcus pneumoniae causes significant infant and child morbidity and mortality globally.
- Serotype distribution of S. pneumoniae is dynamic, influenced by location, time, age, and disease prevalence.
Purpose of the Study:
- To determine the current molecular characteristics of S. pneumoniae strains from pediatric patients in Shanghai, China.
- To assess antibiotic resistance patterns and vaccine coverage.
Main Methods:
- Analysis of 73 clinical S. pneumoniae isolates collected between 2016 and 2018.
- Characterization included capsular serotyping, multilocus sequence typing (MLST), antibiotic susceptibility testing, and identification of resistance genes.
Main Results:
- Serotypes 19F (39.7%), 19A (16.4%), and 6A (11.0%) were most common.
- Clonal complex 271 (ST271) was predominant (37.0%), associated with serotype 19F.
- High resistance rates observed for penicillin (21.9%), ceftriaxone (39.7%), and macrolides (100%), with erm(B) and mef(A/E) genes prevalent.
Conclusions:
- Clonal complex 271 (Taiwan19F-14 clone) drives pneumococcal dissemination in Shanghai.
- Current prevalent serotypes suggest limited effectiveness of the 7-valent pneumococcal conjugate vaccine in this region.
- High macrolide resistance precludes its empirical use in treating pediatric pneumococcal infections.
Background:
Streptococcus pneumoniae is a major cause of bacterial infection among infants and young children with high morbidity and mortality. The serotype distribution of S. pneumoniae varies with geography, time, age, and disease.
Aim:
We aimed to investigate the current status of molecular characteristics of S. pneumoniae strains isolated from pediatric patients in Shanghai, China.
Methods:
Between 2016 and 2018, 73 clinical S. pneumoniae isolates were characterized by capsular serotype, multilocus sequence typing, antibiotic susceptibility, and resistant genes.
Results:
The most common serotypes were 19F (39.7%), 19A (16.4%), 6A (11.0%), 14 (9.6%), and 6B (8.2%). The coverage rates of the 7-, 10- and 13-valent pneumococcal conjugate vaccines were 64.4%, 64.4%, and 91.8%, respectively. The five predominant sequence types were ST271 (37.0%), ST320 (19.2%), ST3173 (11.0%), ST876 (6.8%), and ST81 (4.1%), which were mainly associated with serotypes 19F, 19A, 6A, 14, and 23F, respectively. The rates of resistance to penicillin and ceftriaxone were 21.9% and 39.7%, respectively. All strains displayed resistance to macrolides, 54.8% of which possessed both erm(B) and mef(A/E) genes, and 41.1% carried the erm(B) gene alone. Tn2010 (41.1%) was the most common transposon.
Conclusions:
Clonal complex 271 (Taiwan19F-14 clone) played a dominant role in the dissemination of pneumococcal isolates. The prevalent serotypes indicated a lack of the 7-valent pneumococcal conjugate vaccine, which has not been included in national immunization programs in mainland China. The high rate of macrolide resistance made the empirical use of macrolides alone not suitable for treating pediatric pneumococcal disease.
