NCT06594250

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

• Status: Recruiting
• Phase: —
• Study type: Observational
• Enrollment: 405 (estimated)
• Sponsor: Centre Hospitalier Universitaire de Saint Etienne · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

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.

Detailed 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).

Conditions

• Bacteria Infection Mechanism

Interventions

Type	Name	Description
DIAGNOSTIC_TEST	Nasal swab	Nasal swab to detect nasal carriage of S. aureus
BIOLOGICAL	Venous sampling	Peripheral venous sampling to collect peripheral blood mononuclear cells.
BIOLOGICAL	Antibiotic treatment	Antibiotic treatment for bacteremia (+/- 1 month), in all patients with S. aureus
DEVICE	Nasal swab	A new nasal swab will be taken using the same technique, to see whether or not the carriage persists
BIOLOGICAL	Intracellular reservoir test	In the event of positive carriage, a new intracellular reservoir test will be performed. A search for relapse (new S. aureus infection) or recurrence (S. aureus bacteremia if the 1st bacteremia was due to another pathogen) will be carried out.

Timeline

• Start date: 2024-09-02
• Primary completion: 2025-11-01
• Completion: 2025-11-01
• First posted: 2024-09-19
• Last updated: 2024-09-19

Locations

1 site across 1 country: France