Overview
The aim of the study is to assess whether targeting virulence factors by administering linezolid in addition to standard antibiotic treatment improves outcomes in patients with Staphylococcus aureus bacteraemia.
Description
Staphylococcus aureus (S. aureus) is one of the deadliest bacterial pathogens, especially in high-income countries, and causes bloodstream infections (bacteraemia) in 20-30 per 100,000 people annually. Despite widely available antibiotic treatments, the 90-day mortality rate remains high at 20-30%, and complications such as organ damage, relapses, and long-term impairment affect many survivors. Existing treatments have failed to improve survival rates highlighting the urgent need for novel therapeutic strategies.
Virulence factors produced by S. aureus facilitate bacterial persistence and spread, and tissue damage. Preclinical research suggests that inhibiting the production of virulence factors may improve patient outcomes. While some clinical guidelines recommend this approach for toxin-mediated infections, randomized controlled trials (RCTs) evaluating this approach in S. aureus bacteraemia have not yet been conducted.
Linezolid, an antibiotic commonly used for pneumonia and complicated skin and soft-tissue infections, has shown strong inhibition of the expression of S. aureus virulence factors in preclinical studies. Studies in animal models demonstrated that linezolid, when combined with other antibiotics, enhances treatment efficacy and reduces bacterial toxin production. Observational studies suggest that early initiation of linezolid may lead to better patient outcomes, but no RCT has tested this approach in S. aureus bacteraemia.
This placebo-controlled trial will evaluate whether adding a 5-day course of linezolid to standard antibiotic therapy improves clinical outcomes in patients with S. aureus bacteraemia.
Eligibility
Inclusion criteria:
- Staphylococcus aureus (S. aureus) grown from at least one blood culture
- Hospitalised at a participating centre
- ≥18 years old
- Written informed consent or fulfilling criteria for an emergency exception from informed consent requirements
Exclusion criteria:
- Administration of the initial drug treatment not feasible within 72 hours since the collection of the first positive blood culture with S. aureus
- Documented history of positive blood cultures for S. aureus occurring between 72 hours and 180 days prior to the eligibility assessment
- Necrotising fasciitis
- Currently receiving linezolid or clindamycin
- Use of any monoamine oxidase A or B inhibitor within the last two weeks
- Known hypersensitivity to linezolid or any other ingredients of the study drugs
- Current severe thrombocytopenia (i.e. \<30 x 10\^9/L)
- Application of study drug not possible (per mouth or per gastric tube)
- Currently breastfeeding
- Local treating team believes that death is imminent and inevitable
- Patient is receiving end of life care and antibiotic treatment is not considered appropriate
- Local treating team believes that participation in the study is not in the best interest of the patient
- Any indication that the patient is unwilling to participate in the study including an advance directive stating such unwillingness