Hyperbaric oxygen therapy augments tobramycin efficacy in experimental Staphylococcus aureus endocarditis

Area of Science:

• Infectious Diseases
• Hyperbaric Medicine
• Pharmacology

Background:

• Staphylococcus aureus infective endocarditis (IE) presents a high mortality rate (up to 40%).
• Enhancing antibiotic efficacy and host response is crucial for improving outcomes in IE.
• Hyperbaric oxygen therapy (HBOT) is explored as an adjunctive treatment.

Purpose of the Study:

• To evaluate the efficacy of HBOT combined with tobramycin in a rat model of Staphylococcus aureus IE.
• To assess the impact of adjunctive HBOT on bacterial load, vegetation size, cytokine expression, and clinical status.

Main Methods:

• A rat model of Staphylococcus aureus IE was established.
• Infected rats received subcutaneous tobramycin and were randomized into HBOT or normobaric air groups.
• Quantitative bacteriology, cytokine analysis, vegetation measurements, and clinical scoring were performed.

Main Results:

• Adjunctive HBOT significantly reduced bacterial load in aortic valves, myocardium, and spleen compared to non-HBOT.
• HBOT treatment led to significantly smaller valve vegetations and improved clinical scores.
• Key pro-inflammatory cytokines (IL-1β, IL-6, KC, VEGF) were significantly reduced in the HBOT group.

Conclusions:

• Hyperbaric oxygen therapy augmented the efficacy of tobramycin in treating Staphylococcus aureus IE in rats.
• The findings support the potential use of HBOT as an adjunctive therapy for severe S. aureus IE.
• HBOT demonstrated benefits by reducing bacterial burden, vegetation size, and inflammation.