Gut Microbiome of Patients Undergoing Antibiotic Therapy for Orthopedic Device-related Infection

Study Overview
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Brief Summary
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The microbiome of 80 orthopedic-device related infection (ODRI) patients treated with antibiotics and 10 healthy controls will be investigated. Samples (blood, stool, saliva, skin-swab) are collected 4x within 6 months. Composition and diversity of the microbiome will be assessed by 16sRNA sequencing, skins swabs are screened for rifampicin-resistant staphylococci onto Mannitol-salt-agar plates supplemented with rifampicin, inflammation markers and antibodies in blood and saliva are monitored to track changes in the immune response. For further analysis patients are assigned to one of two groups: 1) antibiotic therapy including rifampicin and 2) non-rifampicin antibiotic therapy.

Official Title
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Investigation of the Microbiome of Patients Receiving Antibiotic Therapy for Orthopedic Device-related Infection

Conditions
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Fractures, Bone, Infection, Bacterial, Joint Infection, Bone Infection

Intervention / Treatment
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* Other: no intervention, observational only


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: The patient is planned to undergo revision surgery due to suspected bone or joint infection. The patient is at least 18 years old Exclusion Criteria: The patient took antibiotics in the previous six weeks of recruitment (a single dose/shot of antibiotics during this period is not considered). The patient suffers from gut-associated morbidities such as Morbus Crohn or colitis ulcerosa. The patient suffers from psychiatric disorders/cognitive impairment affecting understanding. The patient is unable to give consent and follow procedures and/or has insufficient knowledge of the project language.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Antibiotic therapy including rifampicin<br> | Other: no intervention, observational only<br>* no intervention, observational only<br>|
| Non-rifampicin antibiotic therapy<br> | Other: no intervention, observational only<br>* no intervention, observational only<br>|
| Control group (healthy volunteers)<br> | Other: no intervention, observational only<br>* no intervention, observational only<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Composition of the the gut microbiota following two weeks of intravenous antibiotic therapy | The gut microbiota will be characterized by means of 16s rRNA sequencing. The gut microbiota composition following two weeks of intravenous (iv) antibiotic treatment will be compared to baseline samples of the patients. | Two weeks | 
| Composition of the gut microbiota following four weeks of oral antibiotic therapy | The gut microbiota will be characterized by means of 16s rRNA sequencing. The gut microbiota composition following four weeks of oral antibiotic treatment will be compared to baseline samples of the patients. | Six weeks (including two weeks iv and four weeks of oral antibiotic therapy) | 
| Composition of the gut microbiota 24 weeks after antibiotic therapy start | The gut microbiota will be characterized by means of 16s rRNA sequencing. The gut microbiota composition 24 weeks after antibiotic therapy start, including an at least 6-week antibiotic free period, will be compared to baseline samples of the patients. | 24 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Monitoring Rifampicin resistant S. aureus on the skin following two weeks of iv antibiotic therapy | Skin and nose swabs will be plated on (rifampicin supplemented ) Mannitol-Salt-Agar plates and colonies will be compared to baseline samples of the patients. | Two weeks | 
| Monitoring Rifampicin resistant S. aureus on the skin following four weeks of oral antibiotic therapy | Skin and nose swabs will be plated on (rifampicin supplemented ) Mannitol-Salt-Agar plates and colonies will be compared to baseline samples of the patients. | Six weeks (including two weeks iv and four weeks of oral antibiotic therapy) | 
| Monitoring Rifampicin resistant S. aureus on the skin 24 weeks after antibiotic therapy start | Skin and nose swabs will be plated on (rifampicin supplemented ) Mannitol-Salt-Agar plates and colonies will be compared to baseline samples of the patients. | 24 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Gut Microbiome, Joint Infection, Bone Infection, Antibiotic Therapy