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

NCT ID: NCT06594250

Last Updated: 2024-09-19

Basic Information

• Recruitment Status: RECRUITING
• Total Enrollment: 405 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2024-09-02
• Study Completion Date: 2025-11-30

Brief 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

Study Design

• Observational Model Type: COHORT
• Study Time Perspective: PROSPECTIVE

Study Groups

Experimental group

Experimental group comprising patients with S. aureus bacteremia with or without IE

Nasal swab

Intervention Type: DIAGNOSTIC_TEST

Nasal swab to detect nasal carriage of S. aureus

Venous sampling

Intervention Type: BIOLOGICAL

Peripheral venous sampling to collect peripheral blood mononuclear cells.

Antibiotic treatment

Intervention Type: BIOLOGICAL

Antibiotic treatment for bacteremia (+/- 1 month), in all patients with S. aureus

Nasal swab

Intervention Type: DEVICE

A new nasal swab will be taken using the same technique, to see whether or not the carriage persists

Intracellular reservoir test

Intervention Type: BIOLOGICAL

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.

Control group

Control group comprising patients with bacteremia with a pathogenic bacterial species other than S. aureus with or without IE.

Nasal swab

Intervention Type: DIAGNOSTIC_TEST

Nasal swab to detect nasal carriage of S. aureus

Venous sampling

Intervention Type: BIOLOGICAL

Peripheral venous sampling to collect peripheral blood mononuclear cells.

Antibiotic treatment

Intervention Type: BIOLOGICAL

Antibiotic treatment for bacteremia (+/- 1 month), in all patients with S. aureus

Nasal swab

Intervention Type: DEVICE

A new nasal swab will be taken using the same technique, to see whether or not the carriage persists

Intracellular reservoir test

Intervention Type: BIOLOGICAL

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.

Interventions

Nasal swab

Nasal swab to detect nasal carriage of S. aureus

Intervention Type: DIAGNOSTIC_TEST

Venous sampling

Peripheral venous sampling to collect peripheral blood mononuclear cells.

Intervention Type: BIOLOGICAL

Antibiotic treatment

Antibiotic treatment for bacteremia (+/- 1 month), in all patients with S. aureus

Intervention Type: BIOLOGICAL

Nasal swab

A new nasal swab will be taken using the same technique, to see whether or not the carriage persists

Intervention Type: DEVICE

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.

Intervention Type: BIOLOGICAL

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

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Centre Hospitalier Universitaire de Saint Etienne

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Elisabeth BOTELHO-NEVERS, MD-PhD

Role: PRINCIPAL_INVESTIGATOR

CHU SAINT-ETIENNE

Léo SAUVAT, MD

Role: STUDY_CHAIR

CHU SAINT-ETIENNE

Locations

Centre Hospitalier Universitaire de St Etienne

Saint-Etienne, , France

Site Status: RECRUITING

Countries

France

Central Contacts

Elisabeth BOTELHO-NEVERS, MD-PhD

Role: CONTACT

elisabeth.botelho-nevers@chu-st-etienne.fr

(0)477120764 ext. +33

Amandine Gagneux-Brunon, MD-PhD

Role: CONTACT

amandine.gagneux-brunon@chu-st-etienne.fr

(0)477120356 ext. +33

Other Identifiers

2020-A02692-37

Identifier Type: OTHER

Identifier Source: secondary_id

20CH025

Identifier Type: -

Identifier Source: org_study_id