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Updated: Mar 31, 2026
A Murine Model of Group B Streptococcus Vaginal Colonization
Published on: November 16, 2016
Prevalence of emm types and antimicrobial susceptibility of Streptococcus dysgalactiae subsp. equisimilis in Austria
Eva Leitner1, Ines Zollner-Schwetz2, Gernot Zarfel1
1Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, Austria.
Objectives:
An increase of severe infections caused by Streptococcus dysgalactiae subsp. equisimilis (SDSE) similar to infections caused by Streptococcus pyogenes has been reported over the last years. Little is known about infections with SDSE in Austria. Therefore, we investigated a collection of 113 SDSE invasive and non-invasive isolates from different infection sites and type of infections as well as patients' characteristics.
Methods:
The isolates were phenotypically identified and emm typed using the enlarged emm database from the Centers for Disease Control and Prevention. Additionally, 13 antimicrobial agents were tested using EUCAST guidelines and virulence genes were investigated.
Results:
Severe SDSE infections were most common in elderly men with underlying diseases especially diabetes mellitus. With VitekMS identification of SDSE isolates was successful to the species level only. Emm typing revealed 24 different emm types, one new type and one new subtype. StG485, stG6, stC74a, stG643, and stG480 were the predominant types in this study, stC74a and stG652 in invasive infections and stG643, stC74a and stG485 in non-invasive infections. Resistance was observed to tetracycline (62%), macrolides (13%) with one M phenotype, and clindamycin (12%) presenting 6 constitutive MLS(B) phenotypes and 8 inducible MLS(B) phenotypes. Levofloxacin resistance was detected only in one isolate. All isolates tested for virulence genes were positive for scpA, ska, saga and slo. Superantigenic genes were negative except speG(dys) (positive 17/34; 50%).
Conclusion:
This paper presents the first report of SDSE infections in Austria. Severe SDSE infections were found mainly in elderly men with underlying diseases. SDSE isolates demonstrated substantial emm type diversity without association with infections site or invasiveness. Analysis of virulence genes showed no significant difference between invasive and non-invasive infections.
Insights
Severe Streptococcus dysgalactiae subsp. equisimilis (SDSE) infections primarily affect elderly men with underlying conditions. This study reveals significant emm type diversity in Austrian SDSE isolates, with no clear link to infection severity or site.
Area of Science:
- Microbiology
- Infectious Diseases
- Epidemiology
Background:
- Increasing reports of severe infections caused by Streptococcus dysgalactiae subsp. equisimilis (SDSE), similar to Streptococcus pyogenes.
- Limited data on SDSE infections specifically within Austria.
Purpose of the Study:
- To investigate the characteristics of SDSE invasive and non-invasive isolates in Austria.
- To analyze patient demographics, emm types, antimicrobial resistance, and virulence genes of SDSE.
Main Methods:
- Phenotypic identification and emm typing of 113 SDSE isolates.
- Antimicrobial susceptibility testing against 13 agents using EUCAST guidelines.
- Investigation of key virulence genes.
Main Results:
- Severe SDSE infections predominantly occurred in elderly men with comorbidities like diabetes mellitus.
- Emm typing identified 24 distinct emm types, including one novel type and subtype. Predominant types included StG485, stG6, stC74a, stG643, and stG480.
- Significant resistance observed for tetracycline (62%), macrolides (13%), and clindamycin (12%). All isolates carried scpA, ska, saga, and slo virulence genes.
Conclusions:
- This is the first report detailing SDSE infections in Austria.
- SDSE infections are most severe in elderly men with underlying health issues.
- Emm type diversity was high, but not associated with infection site or invasiveness. Virulence gene profiles did not differ significantly between invasive and non-invasive isolates.
