The effects of hyperbaric oxygen administered at different pressures and durations on minumum inhibitöry consentration (mic) values of vancomycin for mrsa

Introduction: S. Aureus is one of the most important causes of community and hospital- acquired infections worldwide. Methicillin-resistant S. Aureus (MRSA) infections, particularly in intensive care units, are increasingly reported. Currently, the most commonly used drugs in the treatment of these infections are antibiotics of the glycopeptide group, including Vancomycin and Teikoplanin. Side effects such as ototoxicity, renal insufficiency, neutropenia, thrombocytopenia, agranulocytosis can be seen after long-term and high dose usege of these antibiotics. Hyperbaric oxygen therapy (HBO) is used as an adjunctive therapy in many climical conditions with infection, especially in cases of diabetic foot, due to its antimicrobial effect. The effects of HBO application on MRSA have been investigated in several studies and the efficacy of HBO treatment alone has been demonstrated even though complete bacterial eradication is not achieved. At the same time, promising results were obtained in groups in which HBO and antibiotics were combined. Method: In this in vitro study, we investigated the effects of normobaric and %100 Oxygen, HBO at 2 and 2,8 ATA for 90 and 300 minutes, on MIC values of vancomycin measured by gradient method for three species of MRSA. Result and conclusion: When normobaric oxygen and hyperbaric oxygen administration were compared with the control group, it was observed that the MIC values of vancomycin were lowered by oxygen. If this synergistic effect is supported by in vivo studies it may be important to prevent toxic effects of dose adjustment of vancomycin when administered in combination with oxygen.