Study of the Nasal Intracellular Reservoir of Staphylococcus Aureus in Patients With S. Aureus Bacteremia
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: Nasal swab, Venous sampling, Antibiotic treatment, Nasal swab.
- Who it may be relevant to
- Registry conditions: Bacteria Infection Mechanism. Basic parameters: from 18 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- France
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Overview
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).
Interventions
- 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.
Primary outcome measures
- Number of intracellular S. aureus carriers at nasal level research [Time frame: At inclusion]
Secondary outcome measures (7)
- Number of intracellular S. aureus carriers at nasal level research [Time frame: Day 7]
- In-hospital mortality rate (%) [Time frame: Month 1]
- Mean duration of S. aureus bacteremia (Day) [Time frame: Month 1]
- Average number of secondary localizations of S. aureus bacteremia [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]
Eligibility criteria
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 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
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Observational model
- Cohort
Study locations
France · 1 center
- Centre Hospitalier Universitaire de St Etienne — Saint-Etienne
Identifiers
NCT: NCT06594250 · 20CH025 · 2020-A02692-37