Back to Journals » Infection and Drug Resistance » Volume 11

Comparative genomic analysis of multidrug-resistant Streptococcus pneumoniae isolates

Authors Pan F, Zhang H, Dong X, Ye W, He P, Zhang SL, Zhu JX, Zhong N

Received 31 July 2017

Accepted for publication 30 January 2018

Published 3 May 2018 Volume 2018:11 Pages 659—670


Checked for plagiarism Yes

Review by Single anonymous peer review

Peer reviewer comments 2

Editor who approved publication: Professor Suresh Antony

Fen Pan,1 Hong Zhang,1 Xiaoyan Dong,2 Weixing Ye,3 Ping He,4 Shulin Zhang,4 Jeff Xianchao Zhu,5 Nanbert Zhong1,2,6

1Department of Clinical Laboratory, Shanghai Children’s Hospital, Shanghai Jiaotong University, Shanghai, China; 2Department of Respiratory, Shanghai Children’s Hospital, Shanghai Jiaotong University, Shanghai, China; 3Shanghai Personal Biotechnology Co., Ltd, Shanghai, China; 4Department of Medical Microbiology and Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai, China; 5Zhejiang Bioruida Biotechnology co. Ltd, Zhejiang, China; 6New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA

Introduction: Multidrug resistance in Streptococcus pneumoniae has emerged as a serious problem to public health. A further understanding of the genetic diversity in antibiotic-resistant S. pneumoniae isolates is needed.
Methods: We conducted whole-genome resequencing for 25 pneumococcal strains isolated from children with different antimicrobial resistance profiles. Comparative analysis focus on detection of single-nucleotide polymorphisms (SNPs) and insertions and deletions (indels) was conducted. Moreover, phylogenetic analysis was applied to investigate the genetic relationship among these strains.
Results: The genome size of the isolates was ~2.1 Mbp, covering >90% of the total estimated size of the reference genome. The overall G+C% content was ~39.5%, and there were 2,200–2,400 open reading frames. All isolates with different drug resistance profiles harbored many indels (range 131–171) and SNPs (range 16,103–28,128). Genetic diversity analysis showed that the variation of different genes were associated with specific antibiotic resistance. Known antibiotic resistance genes (pbps, murMN, ciaH, rplD, sulA, and dpr) were identified, and new genes (regR, argH, trkH, and PTS-EII) closely related with antibiotic resistance were found, although these genes were primarily annotated with functions in virulence as well as carbohydrate and amino acid transport and metabolism. Phylogenetic analysis unambiguously indicated that isolates with different antibiotic resistance profiles harbored similar genetic backgrounds. One isolate, 14-LC.ER1025, showed a much weaker phylogenetic relationship with the other isolates, possibly caused by genomic variation.
Conclusion: In this study, although pneumococcal isolates had similar genetic backgrounds, strains were diverse at the genomic level. These strains exhibited distinct variations in their indel and SNP compositions associated with drug resistance.

Keywords: Streptococcus pneumoniae, antimicrobial resistance, whole-genome sequencing, insertions/deletions, SNPs, phylogenetic analysis

Creative Commons License This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at and incorporate the Creative Commons Attribution - Non Commercial (unported, v3.0) License. By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms.

Download Article [PDF]  View Full Text [HTML][Machine readable]