Comparative genomics identifies a cyl-like region in Streptococcus sinensis isolates from a patient with infective endocarditis
- 1Department of Laboratory Diagnostics, Changhai Hospital, Second Military Medical University
- 2Department of Disease Prevention and Control, Changhai Hospital, Second Military Medical University
Abstract
Streptococcus sinensis is an uncommon member of the viridans group streptococci reported in infective endocarditis (IE), but its genomic characteristics remain incompletely defined. We performed whole-genome sequencing of three S. sinensis isolates recovered from blood culture and valvular tissue from a single patient with IE and compared them with 199 public Streptococcus genomes. Orthology analysis, phylogenetic reconstruction, SNP analysis, VFDB and CARD screening, gene-specific BLAST, Pfam/HMMER analysis, read mapping, synteny comparison, in silico structural modeling, and erythrocyte hemolysis assays were integrated. The three isolates differed by only 0–1 SNPs and formed a near-clonal group. Core single-copy ortholog phylogeny placed S. sinensis closest to S. cristatus , followed by S. sanguinis and S. gordonii . The three isolates retained the host-interaction-associated genes eno , pavA , and plr / gapA and carried an identical 11,341-bp, 12-gene cyl -like block comprising 11 cyl -like genes and acpC . Core-gene phylogeny analysis indicated that the distribution of the complete block was lineage-associated. Gene-specific BLAST and read mapping confirmed full-length sequence conservation and complete mapped-base coverage of the block, while Pfam/HMMER supported enzyme- and transporter-associated domain assignments for several encoded proteins. Structural modeling predicted soluble enzyme-like folds for CylG-like and CylZ-like proteins and a membrane-permease-like architecture with transmembrane helices for CylB-like. On Columbia sheep-blood agar, all three clinical isolates showed visible hemolytic zones and exhibited detectable hemolytic activity in a sheep erythrocyte hemolysis assay. All three S. sinensis isolates shared a type 1 CARD-derived resistance-marker profile containing only Spne_parC_FLO . These findings clarify the phylogenomic position of the near-clonal clinical isolates and identify a shared cyl -like genomic region accompanied by measurable hemolytic activity, providing a basis for further investigation of their host-interaction and pathogenic potential.
Related
- Hepatic Mycotic Aneurysms in TAVI-Associated Infective Endocarditis Caused by Streptococcus gallolyticus: A Case Report.
- Antibiotic Prophylaxis of Infective Endocarditis in Dentistry: An Update on the ESC, AHA, and NICE Guidelines
- Robotic tricuspid valve repair for infective endocarditis with leaflet perforation and severe tricuspid regurgitation
- Integrated Clinical, Biological, and Echocardiographic Factors Independently Associated With In-Hospital Mortality in Infective Endocarditis: A Single-Centre Cohort Study From Morocco
- Tricuspid Valve Infective Endocarditis Seen on Point-of-Care Ultrasound: A Case Report
BibTeX
@article{ma2026comparative,
title = {{Comparative genomics identifies a cyl-like region in Streptococcus sinensis isolates from a patient with infective endocarditis}},
author = {Wei Ma and Yanjun Zhang and Xiaochun Huang and Yuxiang Wan and Changzi Deng and Jia Lin and Li Xu and Qin Qin},
journal = {Frontiers in Microbiology},
year = {2026},
month = oct,
doi = {10.3389/fmicb.2026.1990134},
url = {https://www.frontiersin.org/articles/10.3389/fmicb.2026.1990134/full},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Comparative genomics identifies a cyl-like region in Streptococcus sinensis isolates from a patient with infective endocarditis
AU - Wei Ma
AU - Yanjun Zhang
AU - Xiaochun Huang
AU - Yuxiang Wan
AU - Changzi Deng
AU - Jia Lin
AU - Li Xu
AU - Qin Qin
PY - 2026
DA - 2026/10/19
JO - Frontiers in Microbiology
DO - 10.3389/fmicb.2026.1990134
UR - https://www.frontiersin.org/articles/10.3389/fmicb.2026.1990134/full
AB - Streptococcus sinensis is an uncommon member of the viridans group streptococci reported in infective endocarditis (IE), but its genomic characteristics remain incompletely defined. We performed whole-genome sequencing of three S. sinensis isolates recovered from blood culture and valvular tissue from a single patient with IE and compared them with 199 public Streptococcus genomes. Orthology analysis, phylogenetic reconstruction, SNP analysis, VFDB and CARD screening, gene-specific BLAST, Pfam/HMMER analysis, read mapping, synteny comparison, in silico structural modeling, and erythrocyte hemolysis assays were integrated. The three isolates differed by only 0–1 SNPs and formed a near-clonal group. Core single-copy ortholog phylogeny placed S. sinensis closest to S. cristatus , followed by S. sanguinis and S. gordonii . The three isolates retained the host-interaction-associated genes eno , pavA , and plr / gapA and carried an identical 11,341-bp, 12-gene cyl -like block comprising 11 cyl -like genes and acpC . Core-gene phylogeny analysis indicated that the distribution of the complete block was lineage-associated. Gene-specific BLAST and read mapping confirmed full-length sequence conservation and complete mapped-base coverage of the block, while Pfam/HMMER supported enzyme- and transporter-associated domain assignments for several encoded proteins. Structural modeling predicted soluble enzyme-like folds for CylG-like and CylZ-like proteins and a membrane-permease-like architecture with transmembrane helices for CylB-like. On Columbia sheep-blood agar, all three clinical isolates showed visible hemolytic zones and exhibited detectable hemolytic activity in a sheep erythrocyte hemolysis assay. All three S. sinensis isolates shared a type 1 CARD-derived resistance-marker profile containing only Spne_parC_FLO . These findings clarify the phylogenomic position of the near-clonal clinical isolates and identify a shared cyl -like genomic region accompanied by measurable hemolytic activity, providing a basis for further investigation of their host-interaction and pathogenic potential.
SN - 1664-302X
ER -