Serotype Distribution, Antimicrobial Susceptibility, Multilocus Sequencing Type and Virulence of Invasive Streptococcus pneumoniae in China: A Six-Year Multicenter Study

Menglan Zhou; Ziran Wang; Li Zhang; Timothy Kudinha; Haoran An; Chenyun Qian; Bin Jiang; Yao Wang; Yingchun Xu; Zhengyin Liu; Hong Zhang; Jingren Zhang

doi:10.3389/fmicb.2021.798750

Serotype Distribution, Antimicrobial Susceptibility, Multilocus Sequencing Type and Virulence of Invasive Streptococcus pneumoniae in China: A Six-Year Multicenter Study

Front Microbiol. 2022 Jan 13:12:798750. doi: 10.3389/fmicb.2021.798750. eCollection 2021.

Authors

Menglan Zhou^{1

2}, Ziran Wang^{1

2}, Li Zhang³, Timothy Kudinha^{4

5}, Haoran An^{6

7}, Chenyun Qian^{6

7}, Bin Jiang⁸, Yao Wang^{1

2}, Yingchun Xu^{1

2}, Zhengyin Liu³, Hong Zhang⁹, Jingren Zhang^{5

6}

Affiliations

¹ State Key Laboratory of Complex Severe and Rare Diseases, Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
² Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases, Beijing, China.
³ Department of Infectious Disease, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.
⁴ School of Biomedical Sciences, Charles Sturt University, Orange, NSW, Australia.
⁵ NSW Health Pathology, Regional and Rural, Orange Hospital, Orange, NSW, Australia.
⁶ Department of Basic Medical Science, School of Medicine, Tsinghua University, Beijing, China.
⁷ Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, China.
⁸ Department of Clinical Laboratory, Hunan Provincial People's Hospital, The First Affiliated Hospital of Hunan Normal University, Changsha, China.
⁹ Department of Clinical Laboratory, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, China.

Abstract

Background: Streptococcus pneumoniae is an important human pathogen that can cause severe invasive pneumococcal diseases (IPDs). The aim of this multicenter study was to investigate the serotype and sequence type (ST) distribution, antimicrobial susceptibility, and virulence of S. pneumoniae strains causing IPD in China. Methods: A total of 300 invasive S. pneumoniae isolates were included in this study. The serotype, ST, and antimicrobial susceptibility of the strains, were determined by the Quellung reaction, multi-locus sequence typing (MLST) and broth microdilution method, respectively. The virulence level of the strains in the most prevalent serotypes was evaluated by a mouse sepsis model, and the expression level of well-known virulence genes was measured by RT-PCR. Results: The most common serotypes in this study were 23F, 19A, 19F, 3, and 14. The serotype coverages of PCV7, PCV10, PCV13, and PPV23 vaccines on the strain collection were 42.3, 45.3, 73.3 and 79.3%, respectively. The most common STs were ST320, ST81, ST271, ST876, and ST3173. All strains were susceptible to ertapenem, levofloxacin, moxifloxacin, linezolid, and vancomycin, but a very high proportion (>95%) was resistant to macrolides and clindamycin. Based on the oral, meningitis and non-meningitis breakpoints, penicillin non-susceptible Streptococcus pneumoniae (PNSP) accounted for 67.7, 67.7 and 4.3% of the isolates, respectively. Serotype 3 strains were characterized by high virulence levels and low antimicrobial-resistance rates, while strains of serotypes 23F, 19F, 19A, and 14, exhibited low virulence and high resistance rates to antibiotics. Capsular polysaccharide and non-capsular virulence factors were collectively responsible for the virulence diversity of S. pneumoniae strains. Conclusion: Our study provides a comprehensive insight into the epidemiology and virulence diversity of S. pneumoniae strains causing IPD in China.

Keywords: Streptococcus pneumoniae; antimicrobial susceptibility; molecular epidemiology; serotype distribution; virulence.