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PspA Diversity, Serotype Distribution and Antimicrobial Resistance of Invasive Pneumococcal Isolates from Paediatric
Hanfang Jiang1, Qing Meng2, Xiaorong Liu2
1Clinical Laboratory, Institute of Pediatrics, Shenzhen Children's Hospital, Shenzhen, Guangdong, People's Republic of China.
Insights
Invasive Streptococcus pneumoniae (S. pneumoniae) strains in Shenzhen showed high antimicrobial resistance. Continued surveillance is crucial to monitor antibiotic-resistant and virulent nonvaccine serotypes.
Area of Science:
- Microbiology
- Epidemiology
- Genetics
Background:
- Invasive pneumococcal diseases (IPDs) pose a significant threat to pediatric populations.
- Understanding the molecular epidemiology of Streptococcus pneumoniae (S. pneumoniae) is vital for effective disease control.
Purpose of the Study:
- To characterize the phenotypes and genotypes of invasive S. pneumoniae strains.
- To assess serotype distribution and antimicrobial resistance patterns in pediatric IPDs.
Main Methods:
- Multiplex PCR for serotype profiling.
- pspA gene sequencing for Pneumococcal surface protein A classification.
- Broth microdilution for antimicrobial susceptibility testing.
- Next-generation sequencing for Multilocus sequence typing (MLST).
Main Results:
- 17 serotypes of S. pneumoniae were identified, with 88.9% coverage by the 13-valent pneumococcal conjugate vaccine (PCV13).
- Post-PCV13 introduction, serotypes 15b, 16F, and 20 emerged as nonvaccine serotypes; vaccine serotype 3 showed increased prevalence in severe cases.
- High rates of multidrug resistance (91.3%) were observed, with near-universal resistance to erythromycin (98.8%) and no penicillin resistance in non-meningitis isolates.
Conclusions:
- This study provides a molecular epidemiological profile of invasive S. pneumoniae in Shenzhen.
- Ongoing surveillance of serotype distribution and antimicrobial susceptibility is essential to identify emerging antibiotic-resistant and highly virulent strains.
Introduction:
To determine the phenotypes and genotypes of invasive Streptococcus pneumoniae (S. pneumoniae), 108 strains were isolated from paediatric patients with invasive pneumococcal diseases (IPDs) in Shenzhen from 2014 to 2018.
Methods:
Serotype profiles were defined by multiplex PCR of the capsule gene. Pneumococcal surface protein A (PspA) classification was performed through pspA gene sequencing. Antimicrobial resistance was examined by broth microdilution. Multilocus sequence typing (MLST) was determined based on next-generation sequencing data.
Results:
Eighty-one S. pneumoniae of 17 serotypes were finally collected. The coverage of the 13-conjugated polysaccharide vaccine (PCV13) was 88.9%. After the introduction of PCV13, the nonvaccine serotypes were added by serotypes 15b, 16F and 20. Vaccine serotype 3 increased by four serious cases. The pspA family 1 and pspA family 2 are predominant. The multiple drug resistance rate is 91.3%. None of the nonmeningitis isolates were resistant to penicillin, while 98.8% of all the isolates were resistant to erythromycin.
Discussion:
This work characterizes the molecular epidemiology of invasive S. pneumoniae in Shenzhen. Continued surveillance of serotype distribution and antimicrobial susceptibility is necessary to alert antibiotic-resistant nonvaccine serotypes and highly virulent serotypes.
