Bacteria Infection MechanismRISTANCT06594250
Study of the Nasal Intracellular Reservoir of Staphylococcus Aureus in Patients With S. Aureus Bacteremia
An observational study of Bacteria Infection Mechanism, run by Centre Hospitalier Universitaire de Saint Etienne at 1 site in France.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Bacteria Infection Mechanism
- What is being tested?
- Nasal swab, Venous sampling and Antibiotic treatment
- Type of treatment
- Medical device
- How many people
- 405 participants
- Where
- 1 siteFrance
- Study dates
- 2 Sep 2024to Nov 2027
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: 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).
Who may be able to join
- Bacteremia
- Patient affiliated or entitled to a social security plan
- Patient who has signed a consent form to participate in the study.
Who cannot join
- 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
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Elisabeth BOTELHO-NEVERS, MD-PhD contact
Amandine Gagneux-Brunon, MD-PhD contact
France1 site, 1 recruiting
- Recruiting
Centre Hospitalier Universitaire de St Etienne
Saint-Etienne, 42055
Elisabeth BOTELHO-NEVERS, MD-PhD
Amadine GAGNEUX-BRUNON, MD-PhD
About this study
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.
Read the 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
- Being tested
- Nasal swab, Venous sampling, Antibiotic treatment, Intracellular reservoir test
- Keywords
- Staphylococcus aureus bacteremia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Nasal swabDiagnostic test
Nasal swab to detect nasal carriage of S. aureus
Venous samplingBiological
Peripheral venous sampling to collect peripheral blood mononuclear cells.
Antibiotic treatmentBiological
Antibiotic treatment for bacteremia (+/- 1 month), in all patients with S. aureus
Nasal swabDevice
A new nasal swab will be taken using the same technique, to see whether or not the carriage persists
Intracellular reservoir testBiological
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.
| Study group | Role | What they receive |
|---|---|---|
| Experimental group | Experimental group comprising patients with S. aureus bacteremia with or without IE Receives: Diagnostic Test: Nasal swab; Biological: Venous sampling; Biological: Antibiotic treatment; Device: Nasal swab; Biological: Intracellular reservoir test | |
| Control group | Control group comprising patients with bacteremia with a pathogenic bacterial species other than S. aureus with or without IE. Receives: Diagnostic Test: Nasal swab; Biological: Venous sampling; Biological: Antibiotic treatment; Device: Nasal swab; Biological: Intracellular reservoir test |
What is being measured
The primary outcome is the main question the study is designed to answer.
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
Measured: At inclusion
Secondary outcomes (7)
Number of intracellular S. aureus carriers at nasal level research
Measured: 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
Measured: Month 1
Mean duration of S. aureus bacteremia (Day)
Measured: 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.)
Measured: Month 2
Average length of stay in hospital for S. aureus bacteremia (Day)
Measured: Month 1
Proportion of nasal S. aureus carriers still carriers at the end of treatment for bacteremia (%)
Measured: Month 1
Proportion of nasal S. aureus carriers still carriers one year after the end of treatment for bacteremia (%)
Measured: Month 12
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 Sep 2024
- Study start2 Sep 2024
- Primary completionNov 2027 (estimated)
- Study completionNov 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Bacteria Infection MechanismStudies of the same condition, open and under way.
- More trials run by Centre Hospitalier Universitaire de Saint EtienneThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 405 participants (estimated)
Sponsor and investigators
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Elisabeth BOTELHO-NEVERS, MD-PhD, Principal investigator, Centre Hospitalier Universitaire de Saint EtienneLéo SAUVAT, MD, Study chair, Centre Hospitalier Universitaire de Saint Etienne
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06594250
- Sponsor's protocol ID
- 20CH025
- Other IDs
- 2020-A02692-37
- Acronym
- RISTA
- Status last verified
- Nov 2026
- First submitted
- 10 Sep 2024
- Last updated
- 6 Nov 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 6 Nov 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Study of the Nasal Intracellular Reservoir of Staphylococcus Aureus in Patients With S. Aureus Bacteremia
- ClinicalTrials.gov ID
- NCT06594250
- Acronym / sponsor ID
- RISTA / 20CH025
- Conditions
- Bacteria Infection Mechanism
- Keywords
- Staphylococcus aureus bacteremia
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 405 participants (estimated)
- Lead sponsor
- Centre Hospitalier Universitaire de Saint EtienneUniversity, hospital or other
- Study start
- 2 Sep 2024 (actual)
- Primary completion
- Nov 2027 (estimated)
- Study completion
- Nov 2027 (estimated)
- First posted
- 19 Sep 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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).
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Experimental group | – | Diagnostic Test: Nasal swab, Biological: Venous sampling, Biological: Antibiotic treatment, Device: Nasal swab, Biological: Intracellular reservoir testExperimental group comprising patients with S. aureus bacteremia with or without IE |
| Control group | – | Diagnostic Test: Nasal swab, Biological: Venous sampling, Biological: Antibiotic treatment, Device: Nasal swab, Biological: Intracellular reservoir testControl group comprising patients with bacteremia with a pathogenic bacterial species other than S. aureus with or without IE. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- 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).
Key inclusion criteria (3 listed)
- Bacteremia
- Patient affiliated or entitled to a social security plan
- Patient who has signed a consent form to participate in the study.
Key exclusion criteria (5 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Nasal swabNasal swab to detect nasal carriage of S. aureus | Diagnostic test | Control group, Experimental group |
| Venous samplingPeripheral venous sampling to collect peripheral blood mononuclear cells. | Biological | Control group, Experimental group |
| Antibiotic treatmentAntibiotic treatment for bacteremia (+/- 1 month), in all patients with S. aureus | Biological | Control group, Experimental group |
| Nasal swabA new nasal swab will be taken using the same technique, to see whether or not the carriage persists | Device | Control group, Experimental group |
| Intracellular reservoir testIn 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. | Biological | Control group, Experimental group |
Primary outcome
Number of intracellular S. aureus carriers at nasal level research
Time frame: At inclusion
Number of intracellular S. aureus carriers at nasal level research in patients with S. aureus bacteremia associated or not
7 secondary outcomes
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
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 6 Nov 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Elisabeth BOTELHO-NEVERS, MD-PhD contact
Amandine Gagneux-Brunon, MD-PhD contact
Elisabeth BOTELHO-NEVERS, MD-PhD principal investigator
Centre Hospitalier Universitaire de Saint Etienne
Léo SAUVAT, MD study chair
Centre Hospitalier Universitaire de Saint Etienne
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Bacteria Infection Mechanism, run by Centre Hospitalier Universitaire de Saint Etienne at 1 site in France.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 6 Nov 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in France. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Elisabeth BOTELHO-NEVERS, MD-PhD ((0)477120764 ext. +33, elisabeth.botelho-nevers@chu-st-etienne.fr), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of intracellular S. aureus carriers at nasal level research (time frame: At inclusion). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 6 Nov 2026.