Study of the Nasal Intracellular Reservoir of Staphylococcus Aureus in Patients With S. Aureus Bacteremia

Phase

N/A

Condition

Soft Tissue Infections

Sepsis And Septicemia

Treatment

Nasal swab

Venous sampling

Clinical Study ID

NCT06594250

20CH025

2020-A02692-37

Ages > 18
All Genders

Study Summary

Staphylococcus aureus bacteremia is a serious infection associated with a high mortality rate (with or without associated infective endocarditis (IE)), long hospital stays and multiple complications, due to the terrain in which it occurs and its secondary localization. They may be community-acquired or healthcare-associated infections. Being a carrier of S. aureus is a known risk factor for S. aureus bacteremia. Although several mucosal sites of carriage have been described, screening for carriage is most often carried out at the nasal level, both for reasons of simplicity and because it is the predominant site of carriage of this bacterium. However, S. aureus carriage is a frequent occurrence, affecting around 1/3 of the general population.

Eligibility Criteria

Inclusion

Inclusion Criteria:

Bacteremia
Patient affiliated or entitled to a social security plan
Patient who has signed a consent form to participate in the study.

Exclusion

Exclusion Criteria:

Antibiotic therapy in place for more than 5 days at the time of inclusion
Nasal decolonization of S. aureus within 12 months
Pregnant or breast-feeding women
Patients under guardianship
Polymicrobial bacteremia including S. aureus

Study Design

Nasal swab

September 02, 2024

November 30, 2025

Study Description

Long considered an extracellular bacterium, the investigators now know that S. aureus can have an intracellular reservoir. This was initially described in situations of infection (bone infections, vascular infections) and more recently in situations of nasal carriage without associated infection. Among S. aureus carriers, between 15% and 30% have an intracellular reservoir of this bacterium, depending on the study, in patients with no S. aureus infection. For S. aureus carriers with S. aureus infection, there are no data in the literature. The clinical significance of this intracellular reservoir in a carrier situation is currently unknown. The study team was able to demonstrate in vitro that this reservoir was not affected by the mupirocin used in decolonization, and preliminary results suggest that in vivo this reservoir may also be associated with decolonization failure.

Moreover, in vitro, it has been suggested that S. aureus may act on autophagy to promote intracellular survival. Is the intracellular reservoir more frequent in patients with S. aureus bacteremia? Is it associated with a poorer prognosis in S. aureus bacteremia? Is it associated with the production of certain S. aureus intracellular persistence factors? Is it associated with a slowdown in autophagic flow in nasal cells or phagocytes? These questions remain unanswered to this day.

To explore these questions, the investigators plan to conduct a study to assess the frequency of the intracellular S. aureus reservoir (within carriers) in S. aureus bacteremia and in bacteremia to another pathogen (control group). They would also like to study the impact of this reservoir on the persistence of carriage and prognosis (death, duration of bacteremia, length of stay, presence of secondary localizations of bacteremia or endocarditis in the case of S. aureus bacteremia).

Connect with a study center

Centre Hospitalier Universitaire de St Etienne
Saint-Étienne, 42055
France
Active - Recruiting

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