Staphylokinase and ABO Group Phenotype: New Players in Staphylococcus Aureus Implant-associated Infections Development

Study Overview
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Brief Summary
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The purpose of this study is to identify bacterial and/or clinical features involved in the pathogenesis of Staphylococcus aureus implant-associated infections (IAI). Materials & methods: In total, 57 IAI S. aureus and 31 nasal carriage (NC) S. aureus isolates were studied. Staphylococcus aureus genetic background was obtained by microarray analysis. Multilocus sequence typing was performed to determine clonal complexes (CC). Biofilm production was investigated by resazurin and crystal violet methods

Official Title
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Staphylokinase and ABO Group Phenotype: New Players in Staphylococcus Aureus Implant-associated Infections Development

Conditions
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Staphylococcal Infection

Intervention / Treatment
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* Other: IAI infection
* Other: Staphylococcus aureus nasal carriage infection


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: infected patients with S. Aureus IAI infection noninfected patients screened for S. aureus nasal colonization at the orthopedic consultation ward Exclusion Criteria: minor
Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| IAI patients group<br>patients with Staphylococcus aureus of implant-associated infections | Other: IAI infection<br> <br> |
| control group<br>patients with Staphylococcus aureus nasal carriage | Other: Staphylococcus aureus nasal carriage infection<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| biofilm production measurement in the two groups | The primary aim of this study is to identify phenotypic (biofilm production) markers in two different groups of S. aureus strains isolated from patients with IAI or screened from nasal carrier in noninfected patients undergoing orthopedic surgery. By using resazurin method, IAI and NC nasal carriage isolates were divided into three groups. Isolates were classified as strong, moderate and weak biofilm producers. | september 2012 | 
| Clonal complexes distribution | The primary aim of this study is to identify genotypic markers in two different groups of S. aureus strains isolated from patients with IAI or screened from nasal carrier in noninfected patients undergoing orthopedic surgery. IAI and NC isolates genetic background was determined in order to compare the prevalence of individual virulence factor genes. All genes provided by the Alere StaphyType DNA microarray were studied. | september 2012 | 
| IAI and NC nasal carriage isolates genetic background | IAI and NC isolates genetic background was determined in order to compare the prevalence of individual virulence factor genes. All genes provided by the Alere StaphyType DNA microarray were studied | september 2012 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| biofilm production correlation with genotype | quantile-quantile (QQ)-plot analysis | december 2013 | 
| Correlation between Clonal Complexes distribution , genotype and clinical parameters | In order to determine whether clusters of S. aureus could be associated with clinical characteristics of the patients, search of association between CCs and clinical data was performed | december 2013 | 
| Association of ABO group phenotype and IAI S. aureus genotype | QQ-plots analysis | december 2013 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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biofilm, staphylokinase, Staphylococcus aureus, microarrays, bone binding sialoprotein, bone and joint infection, blood group