Nasal Carrying by Staphylococcus Aureus ST398 Strains in Community and Hospital Settings

Study Overview
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Brief Summary
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The aim of this study was to compare the prevalence of nasal carrying of SA ST398 strains in community and hospital settings, identify the factors associated with colonization of SA ST398, determine the distribution of imported and acquired cases among SA ST398 hospital cases and characterize the genetic structure of the ST398 SA population involved in colonization.

Detailed Description
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Staphylococcus aureus (SA) is a ubiquitous bacterium, part of the human commensal flora. The mucosa of the anterior nasal cavities represents the preferred site of colonization of SA. The SA ST398 clone, belonging to CC 398, was initially described as a zoonotic agent initially identified in France and the Netherlands. In fact, ST398 strains are separated into two distinct populations: a methicillin-resistant SA population (SAMR) with notion of contact with animals and a more virulent methicillin-sensitive SA population (SAMS) than its counterpart, isolated from serious human infections and without notion of exposure to farm animals. Recently, we have shown that, in SA bacteremia, all strains of SA ST398 are sensitive to methicillin and that the prevalence of ST398 among all SAMS responsible for bacteremia at Besançon University Hospital increased between 2009 and 2014, increased from 4 to 15%. However, we were unable to study nasal colonization to support the mode of acquisition of SA ST398 (community vs. healthcare acquisition).

Official Title
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Nasal Carrying by Staphylococcus Aureus ST398 Strains in Community and Hospital Settings

Conditions
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Staphylococcus Aureus Nasal Carriage

Intervention / Treatment
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* Procedure: Nasal swab


Participation Criteria
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Eligibility Criteria
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For community patients : Inclusion Criteria: the selection criteria for blood donation age ≥ 18 years old No refusal of the person Exclusion Criteria: None For hospitalized patients : Inclusion Criteria: age ≥ 18 years old hospitalization in one of the services participating in the study no refusal of the person Exclusion Criteria: None

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Hospitalized patients<br>Within 48 hours of admission to participating departments, all patiens will be included. A nasal swab will be performed within the first 48 hours and on the 7th day. | Procedure: Nasal swab<br>* In hospitalized patiens, a nasal swab will be performed within the first 48 hours and on the 7th day. In community patient, only one swab will be performed<br>|
| Community patients<br>People coming to donate blood in Etablissement Français du Sang will be included and a nasal swab will be performed | Procedure: Nasal swab<br>* In hospitalized patiens, a nasal swab will be performed within the first 48 hours and on the 7th day. In community patient, only one swab will be performed<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of patients nasal carrying of SA ST398 strains in community and hospital settings | Number of patients with SA ST398 positive nasal swab in community will be compared with number of patients with SA ST398 positive nasal swab in hospital | One day | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of patietns with specific Clinical and demographic data associated with nasal carrying of SA ST398 | Clinical and demographic (sex, age, gender, comorbidities, tabaco...) data will be compared between patients with SA ST398 positive nasal swab and SA ST398 negative nasal swab | One day | 
| Number of patients with SA ST398 positive nasal swab to seven days of hospitalization | Number of patients with SA ST398 positive nasal swab to seven days of hospitalization will be compared with the number of patients with SA ST398 positive nasal swab within the first 48 hours of hospitalization | 7 days | 
| Number of virulence gene in SA ST 398 strains | Presence of virulence gene in SA ST 398 strains | One day |