October 5, 2023


In set up

O-SNAP: Optimizing antibiotic dosing in the Staphylococcus aureus Network Adaptive Platform trial

We are inviting you to take part in this sub study because you have joined the SNAP platform or registry, and you are currently staying at a hospital that is running this sub-study.

  • This sub-study aims to find out how much antibiotic we should be giving to adults and children with Staphylococcus aureus blood stream infection (SAB), so that they get the best treatment result.
  • To figure this out, we will look at how antibiotics move into, through, and out of your body (pharmacokinetics) as well as the amount of antibiotics in your blood required to treat their SAB  (pharmacodynamics).
  • By collecting this information, we hope to find out how much antibiotic (i.e., the dose) we should be giving to adults and children to get the best treatment result

Additionally,for patients with Penicillin-susceptible Staph aureus (PSSA) or Methicillin-susceptible Staph aureus (MSSA) SAB the study will also explore:

  • how the body’s immune system responds to theantibiotic used for the SAB
  • if the antibiotic levels can be measured using very small amount of blood (similar to testing blood sugar levels for diabetes)
  • How much staph aureus bacteria is in the body after the first few days of antibiotic treatment

This sub-study is being conducted in Australia.

Lead Investigators: 

Name: A/Prof Amanda Gwee, Murdoch Children's Research Institute (MCRI)


Name: Prof Jason Roberts, The University of Queensland (UQ)


What will the substudy involve – more information

Please read the below information to learn more about the assessments and tests involved in this substudy.

Blood Tests: You will have extra blood collected when you are already having blood tests ordered by your doctor. If you are an adult with PSSA or MSSA SAB, you may have blood tests that are additional to the blood tests ordered by your doctor.

We will take extra blood at a maximum of 5 timepoints per day in adult and children 2 years or older, and a maximum of 3 timepoints per day in children aged 1 to 2 years.

The volume of extra blood collected at each timepoint will be 2-6 ml (up to 1 teaspoon) for adults and 0.5 ml (one tenth of a teaspoon) for children.

Your blood willbe tested for:

  • The amount of antibiotic in your blood
  • The amount of Staphylococcus aureus in your blood
  • For adults only: Immune markers that your body produces in response to infection
Risks and benefits of taking part in the sub study

The collection of blood samples may cause some discomfort. Blood tests may cause possible bruising, redness, and swelling around the site, bleeding at the site, feeling of light-headedness when the blood is taken, and rarely, an infection at the site of the blood test or fainting.

You may have none, some, or all of these, and they may be mild, moderate or severe. If you have any of these side effects or are worried about them, you can talk with the study investigators or your doctor.

Where will my sub study information be collected and stored?

Your information will be kept strictly confidential.

Your information collected for this sub-study will be stored in a database hosted by the Murdoch Children's Research Institute (MCRI).

This data will be de-identified, meaning you will not be able to be identified by these data.

More information about shipment and storage of my samples collected for this substudy

All samples collected for this sub study will be securely stored at Murdoch Children’s Research Institute (MCRI), South Australian Health and Medical Research Institute (SAHMRI) or The University of Queensland (UQ) in Australia, and will then be destroyed after the completion of the substudy.

Your sub study samples, and any paperwork with the samples, cannot identify you. Your samples will be assigned a unique identifying code, but not your name or other individually identifiable information.

You may request that your stored samples be destroyed at any time by contacting the sub study lead, using the contact details provided.

What if I withdraw from this sub study?

You can withdraw from the sub study at any time, just notify a member of the SNAP study team.

If you withdraw, we will keep any information we have collected about you up until you withdraw. If you do not agree with this,you should not join the study.

Substudies in Progress

SNAP Trial


Combination Cefazolin with Ertapenem for methicillin-susceptible Staphylococcus aureus bacteremia.

All Interested
Substudy in Progress


Daptomycin vs. Vancomycin for the Treatment of MRSA bacteremia

All Interested
Substudy in Progress


Profiling the genetic and epigenetic determinants that predispose to severe manifestations of Staphylococcus aureus bacteremia

All Interested
Substudy in Progress