Related Experiment Video
Updated: Sep 28, 2026
A Pre-Clinical Model of Synovitis Using Ex vivo Human Synovial Tissue with Preserved Function and Architecture
Published on: March 20, 2026
Comparison between adult endocarditis due to beta-hemolytic streptococci (serogroups A, B, C, and G) and
Agnès Lefort1, Olivier Lortholary, Philippe Casassus
1Fédération de Médicine Interne, Maladies Infectieuses et Tropicales, Hôpital Avicenne, Université Paris-Nord, Bobigny, France.
Background:
Limited data exist on infective endocarditis (IE) due to Streptococcus milleri (Sm) or beta-hemolytic streptococci (BHS). Because BHS and Sm share some physiologic and pathogenic properties, we wondered whether IE caused by these streptococci might present similarities.
Methods:
Through a nationwide retrospective study in France, the medical and microbiologic charts of adults with definite Sm or BHS IE observed between January 1, 1991, and December 31, 1996, in university and general hospitals were reviewed.
Results:
Fifty-six patients had BHS IE (33 men and 23 women; median age, 59 years; range, 18-91 years) and 29 had Sm IE (18 men and 11 women; median age, 66 years; range, 37-97 years). The BHS group tended to have more underlying medical conditions (46%) and fewer previous cardiopathies (48%) than the Sm group (28% and 71%, respectively). Multivariate analysis showed that a longer median time of IE evolution before diagnosis and identification of the presumed portal of entry were independently associated with Sm IE (P<.01). Extracardiac complications were more frequent in the BHS group (55%) than in the Sm group (39%). Comparison of echocardiographic findings between the 2 groups did not establish any statistically significant difference. Thirty-six patients (64%) in the BHS group and 18 (62%) in the Sm group underwent valve replacement. Overall, mortality was 27% for the BHS group and 14% for the Sm group. For all patients, multivariate analysis retained older age as the only significant risk factor for death (P =.01).
Conclusion:
Compared with Sm IE, BHS IE occurs in younger patients with more underlying diseases and fewer underlying cardiopathies and has a more aggressive presentation and evolution.
Insights
Infective endocarditis (IE) caused by beta-hemolytic streptococci (BHS) affects younger patients with more comorbidities and presents more aggressively than Streptococcus milleri (Sm) IE. BHS IE also shows higher rates of extracardiac complications and mortality.
Area of Science:
- Cardiology
- Infectious Diseases
- Microbiology
Background:
- Limited data exist on infective endocarditis (IE) caused by Streptococcus milleri (Sm) and beta-hemolytic streptococci (BHS).
- These streptococcal groups share physiologic and pathogenic properties, prompting investigation into similarities in IE presentation.
Purpose of the Study:
- To compare the clinical characteristics and outcomes of IE caused by Sm and BHS.
- To identify differences in patient demographics, comorbidities, presentation, and mortality between Sm IE and BHS IE.
Main Methods:
- Nationwide retrospective study in France (1991-1996).
- Review of medical and microbiologic charts of adult patients with definite Sm or BHS IE.
- Multivariate analysis to identify independent risk factors for presentation and death.
Main Results:
- BHS IE (n=56) occurred in younger patients (median age 59) with more underlying conditions and fewer cardiopathies compared to Sm IE (n=29, median age 66).
- BHS IE showed more frequent extracardiac complications (55% vs. 39%) and higher mortality (27% vs. 14%).
- Older age was the only significant risk factor for death in all patients.
Conclusions:
- Beta-hemolytic streptococci IE presents more aggressively than Streptococcus milleri IE.
- BHS IE is associated with younger patients, more comorbidities, fewer cardiopathies, and increased complications and mortality.
- Understanding these differences is crucial for managing streptococcal infective endocarditis.
