An observational study in Bacteria Infection Mechanism, sponsored by Centre Hospitalier Universitaire de Saint Etienne. Recruiting at 1 site in France. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-11-06.
Sponsored by Centre Hospitalier Universitaire de Saint Etienne · Observational
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.
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).
Centre Hospitalier Universitaire de Saint Etienne is the lead sponsor of 597 studies on the registry; 127 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Patients treated at St-Etienne University Hospital with bacteremia with or without IE. Patients will be assigned to the experimental group in the case of S. aureus bacteremia (whether or not associated with an IE), or to the control group in the case of bacteremia caused by a pathogenic bacterium other than S. aureus (whether or not associated with an IE).
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Experimental group comprising patients with S. aureus bacteremia with or without IE
Diagnostic Test: Nasal swab · Biological: Venous sampling · Biological: Antibiotic treatment · Device: Nasal swab · Biological: Intracellular reservoir test
Control group comprising patients with bacteremia with a pathogenic bacterial species other than S. aureus with or without IE.
Diagnostic Test: Nasal swab · Biological: Venous sampling · Biological: Antibiotic treatment · Device: Nasal swab · Biological: Intracellular reservoir test
Nasal swab to detect nasal carriage of S. aureus
Peripheral venous sampling to collect peripheral blood mononuclear cells.
Antibiotic treatment for bacteremia (+/- 1 month), in all patients with S. aureus
A new nasal swab will be taken using the same technique, to see whether or not the carriage persists
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.
Number of intracellular S. aureus carriers at nasal level research
Number of intracellular S. aureus carriers at nasal level research in patients with S. aureus bacteremia associated or not
Time frame: At inclusion
Number of intracellular S. aureus carriers at nasal level research
Time frame: Day 7
In-hospital mortality rate (%)
In-hospital mortality rate directly related to infection (septic shock, multivisceral failure, death during surgical management related to infection) during bacteremia
Time frame: Month 1
Mean duration of S. aureus bacteremia (Day)
Time frame: Month 1
Average number of secondary localizations of S. aureus bacteremia
Clinically diagnosed, or on examination carried out as part of the extension work-up performed as part patient management (Scan, echocardiography, scintigraphy, etc.)
Time frame: Month 2
Average length of stay in hospital for S. aureus bacteremia (Day)
Time frame: Month 1
Proportion of nasal S. aureus carriers still carriers at the end of treatment for bacteremia (%)
Time frame: Month 1
Proportion of nasal S. aureus carriers still carriers one year after the end of treatment for bacteremia (%)
Time frame: Month 12
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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