Staphylococcus aureus (S. aureus) bloodstream infection is one of the most serious bacterial infections worldwide. All patients need to be hospitalised and adults typically will receive a minimum of two weeks intravenous antibiotics.
S. aureus normally lives on your skin or in your nose. It is commonly called ‘golden staph’ as it looks like small golden balls under a microscope. When S. aureus gets into your blood through a sore or a cut in the skin, this can cause a bloodstream infection.
S. aureus bloodstream infections can make you very sick and can affect parts of your body like the lungs, heart, bones, and muscles.
There are three types of S. aureus blood stream infection:
• Penicillin-susceptible S. aureus which is also called PSSA
• Methicillin-susceptible S. aureus which is also called MSSA
• Methicillin-resistant S. aureus which is also called MRSA
While we have effective antibiotic treatments for S. aureus bloodstream infections, it is not known which of these are the best. There are only a few published studies that compare current available treatments. Fewer than 3,000 participants combined have ever been enrolled in published randomised controlled trials for treatments of S. aureus bloodstream infection. The SNAP study will evaluate a range of antibiotic treatments for S. aureus with the aim of improving outcomes for patients.
There are currently three parts to the study, which we call ‘domains’. To find out more about each of these, please watch the videos below:
• Antibiotic backbone domain
• Adjunctive treatment domain
• Early oral switch domain
The SNAP study is being conducted by researchers across Australia, Canada, New Zealand, Singapore, Israel and the United Kingdom, and has the potential to include sites elsewhere in the world.
The lead sponsor for the study is The Peter Doherty Institute for Infection and Immunity (The Doherty Institute), University of Melbourne.
Each country conducting the study will have their own regional sponsor.
If you decide to participate in the study, you will be asked to give consent. This means you will be asked to sign a consent form, which you will also be given a copy to keep. You will then be randomly allocated to different treatments in up to three ‘domains’. To learn more about each domain, see our videos here. Each domain has certain eligibility criteria to ensure it is safe for you to participate.
If you agree to take part in SNAP you can withdraw at any time without giving a reason; this will not affect any of the care you receive.
It is ok if you do not want to take part, this decision will not affect any of the care or treatments you will receive while you are in hospital.
If you decide not to participate in the study, you will be given the standard antibiotic treatments that are used in this hospital- which may actually be the same treatments you would have received in the study.
S. aureus bloodstream infections are always treated with antibiotics. The antibiotics used in this study are not experimental drugs. In fact, the antibiotics are already very widely and frequently used in clinical care.
Most side effects from the antibiotics used are mild, such as diarrhoea, thrush and a rash. Very rarely, more severe side effects might happen, such as liver or kidney impairment, muscle damage or low white cells, but these usually get better when the treatment is stopped. As part of this study the treating doctors will closely monitor you for all of these side effects during your hospital admission and the study medication will be stopped if you experience any severe side effects.
Below is a list of antibiotics which may be used in this study, depending on what country you live in and what domains you take part in:
Treatments that you may be randomly allocated to receive:
Treatments that you may be prescribed by your treating doctor:
Please note: The antibiotics listed in the table above are representative for each drug. If you want to know more about the specific brand that you have been prescribed, please use the following links and search using the antibiotic name:
Australia: Australian Register of Therapeutic Goods
Canada: Canadian Drug and Health Product Register
New Zealand: MEDSAFE Consumer Medicine Information
United Kingdom: MHRA Register of Products
There are no costs associated with participating in this study, nor will you be paid. All medication required as part of the study will be provided to you free of charge.
If you have any complaints about the conduct of the study or any of the study team you have the right to make a complaint, this will not affect any care or treatment that you are receiving. For contact details to make a complaint please click on the relevant country:
Reviewing Human Research Ethics Committee:
Melbourne Health Complaints contact person
Name: Director Research Governance and Ethics
Positions: Complaints Manager
Telephone: (03) 9342 8530
University of MelbourneName: Office of Research Ethics and Integrity
SNAP Trial Management Group:
Telephone: 03 8344 2554
Hospital Research Governance Office
New South Wales
Australian Capital Territory
Sponsor Name: The Research Institute of the McGill University Health Centre
For any complaints concerning the conduct of the study at your treating centre in Canada, please refer to the contact information on your consent form.
Reviewing Human Research Ethics Committee:
Name: Health and Disability Ethics Committee
Telephone: 0800 4 ETHICS
Middlemore Clinical Trials: Grants Manager
SNAP Trial Management Group:
Telephone:+61 3 8344 2554
Hospital Research Governance Office:
Click on your region here for further information.
You will be given a participant card with the study team details to keep with you at all times, and you will be able to use the contact details to contact the study team at any time if you have any questions or concerns.
Almost all of the results collected during your time on this study will be from tests that would have been done even if you were not in the trial.
The hospital staff will record results from your routine tests and observations while you are in hospital (for example blood tests, temperature, symptoms, treatments). You will also be monitored for any side effects.
As part of the study, we will also collect samples of bacteria grown from your blood cultures. These will be stored and sent to a central laboratory for analysis. The results from these will help researchers better understand why infections with particular types of S. aureus respond differently to the antibiotic treatments.
When patients are unwell with an infection, blood samples are often taken to try to culture or grow germs from the blood. Blood is usually sterile, so the growth of a germ is an indication there is an infection in the body caused by that germ. If a Staph aureus is grown, then we call this a Staph aureus bloodstream infection. Patients with Staph aureus bloodstream infections are notified to the SNAP study team for consideration for the SNAP trial.
As part of standard clinical care, after identifying Staph aureus from the bloodstream, the bacterial isolate is further grown on culture media in the laboratory to allow testing for antibiotic susceptibility. The bacterial isolate is then usually frozen by the local laboratory in case further testing is required in the future. To help us better understand if there are factors associated with the Staph aureus isolate and outcomes from the bloodstream infection, we will be storing and then analysing these Staph aureus isolates. The Staph aureus isolates will be indefinitely stored at the University of Melbourne.
Analyses may include determining the susceptibility against different antibiotics, the kinds of toxins and proteins the isolate produces, and the DNA sequence of the isolate. The stored bacterial isolate does not contain any human tissue and is not considered to be a human biospecimen according to the National Health & Medical Research Council (NHMRC National Statement Chapter 3.2; National Statement on Ethical Conduct in Human Research 2007 [Updated 2018]; Chapter 3.2, page 47).
We will also ask your permission to link your study information to existing datasets, such as hospital records, medications, emergency department, and registries of births, deaths and marriages, to allow longer follow-up.
As part of the study, we will also collect data for a registry of patients with S. aureus bloodstream infection. The registry will be used to improve current practice and quality of care.
All of the information collected as part of the Registry is from data that is routinely collected as part of your routine care and will be collected from your medical notes.
Any identifiable information that is collected about you in connection with this study will remain confidential and will comply with all relevant country specific privacy legislation. If required, the regulatory authorities and an authorised representative of the trial Sponsor may require access to your personal information to ensure the clinical trial is compliant with the regulatory and safety requirements. The length of storage for identifiers and privacy legislations varies from country to country as indicated below:
Following study close out and locking of the database, data will be stored on the servers of the University of Melbourne. All analyses performed and the final data set will be archived together according to the University standard operating procedures. These records will be kept for a minimum of 15 years after the completion of the trial before being destroyed or erased, as per the National Health and Medical Research Councils guidelines. For further information on Australian clinical trials legislation, regulation and guidelines including the Commonwealth privacy Act (1988) please click here.
All identifiable data will be kept within your treating centre. Only de-identified data will be shared with international investigators which contains only a study code number in place of your name. Following study close out and locking of the database, data will be stored on the servers of the University of Melbourne. All analyses performed and the final data set will be archived together according to their university standard operating procedures. These records will be kept for a minimum of 15 years after the completion of the trial before being destroyed or erased, as per the Australian National Health and Medical Research Councils guidelines. In Canada, the McGill University Health Centre will receive a copy of the Canadian patient data which will be maintained for 25 years in accordance with Health Canada requirements. The separate database which links your name to your study code will be maintained at each participating centre for up to 25 years as per Health Canada requirements.
Following study close out and locking of the database, data will be stored on the servers of the University of Melbourne. All analyses performed and the final data set will be archived together according to the University standard operating procedures. These records will be kept for a minimum of 10 years after the completion of the trial before being destroyed or erased, as per the Medsafe and Ministry of Health guidelines. For further information on New Zealand clinical trials legislation, regulation and guidelines please click here.
SNAP is a trial that adapts as we proceed. Once one treatment is found to be clearly better than another treatment, patients will continue to receive the better treatment and the poorer treatment is removed from the trial. With many hospital trial sites around the world, we should be able to recruit patients rapidly and allow us to reach appropriate conclusions as quickly as possible. As data accumulates, trial statisticians will analyse the data in near real-time. An independent data and safety monitoring committee will be reviewing these analyses to ensure patient safety is maintained and that results are acted upon in a timely and appropriate manner.
The advantages over other trial designs is:
the trial is continuous
as new interventions/treatments become available they can be added into the trial for comparison to current treatments
multiple questions can be answered simultaneously
answers to questions can be concluded when sufficient data have accrued, not when a specific sample size is met
the information collected from patients already participating in the study can be used to help guide the treatment of new patients joining the study
Interactions between interventions in different domains can be evaluated
With an adaptive design, existing patients can help guide treatment of new patients. Regular data analysis timepoints are built into the trial and interventions will be changed if during the analyses, an intervention is shown to be either:
Much better (continue with this intervention)
Currently no difference (continue with interventions until a difference is found)
Not as effective (stop this intervention)
If a new intervention becomes available include the intervention into the study
If you would like to find out more information about adaptive clinical trials please watch the videos below.
SNAP Trial Learning ResourcesView All
Learn more about why we’re studying treatments for S. aureus bloodstream infections in the SNAP trial.
What does taking part in SNAP mean for participants?
Watch this video to learn more about the SNAP Antibiotic Backbone Domain.