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Updated: Mar 18, 2026
A Murine Model of Group B Streptococcus Vaginal Colonization
Published on: November 16, 2016
First molecular evidence of intrauterine and surgical-site infections caused by Streptococcus dysgalactiae subsp.
Binghuai Lu1, Baowei Diao, Yujie Fang
1Civil Aviation General Hospital, Beijing, China. zs25041@126.com.
Abstract:
S. dysgalactiae subsp. equisimilis (SDSE) is infrequently associated with maternal infections during delivery in pregnant women. A rare case is presented of a woman with intrauterine infection and surgical-site infection due to SDSE after cesarean section, which had colonized her genital tract and, via the ascending pathway, reached her intact fetal membrane. All isolates were identified as Streptococcus Lancefield group G, and their emm genes that coded M protein belonged to stG6.1. The isolates tested negative for a series of streptococcal superantigen virulence genes but positive for nonsuperantigenic virulence genes. In particular, molecular typing using pulsed-field gel electrophoresis analysis disclosed that the three isolates from the different infection sites had identical profiles. Furthermore, multilocus sequence typing indicated that the three isolates belonged to a new sequence typing. Our results indicated that SDSE is potentially pathogenic for pregnant women and newborns if colonized.
Insights
Streptococcus dysgalactiae subsp. equisimilis (SDSE) can cause rare but serious maternal infections during childbirth. This case highlights SDSE
Area of Science:
- Microbiology
- Obstetrics
- Infectious Diseases
Background:
- Streptococcus dysgalactiae subsp. equisimilis (SDSE) is rarely linked to maternal infections.
- Pregnancy and childbirth present unique risks for certain bacterial infections.
Observation:
- A rare case of intrauterine and surgical-site infection caused by SDSE in a woman post-cesarean section is detailed.
- SDSE colonized the genital tract and ascended to infect intact fetal membranes.
Findings:
- Isolates were identified as Streptococcus Lancefield group G, stG6.1 emm type.
- Molecular typing (PFGE, MLST) revealed identical profiles and a novel sequence type for the isolates.
- SDSE isolates were positive for non-superantigenic virulence genes.
Implications:
- SDSE demonstrates potential pathogenicity in pregnant women and newborns.
- This case underscores the importance of recognizing SDSE as a potential pathogen in obstetric settings.
- Further research into SDSE virulence factors and transmission in pregnant populations is warranted.
