Staphylococcus aureus (SA) causes superficial and severe endovascular infections. The present in vitro study investigates the anti-SA mechanisms of hyperbaric oxygen therapy (HBOT) on direct bacterial killing, antibiotic potentiation, and polymorphonuclear leukocyte (PMN) enhancement. SA was exposed to isolated human PMNs, tobramycin, ciprofloxacin, or benzylpenicillin. HBOT was used as one 90-min session. Bacterial survival was evaluated after 4 h by quantitative bacteriology. PMN functionality as reactive oxygen species (ROS) production was measured by means of dihydrorhodamine 123 analysis. We showed that HBOT exhibits significant direct anti-SA effects. HBOT increased the anti-SA effects of PMNs by 18% after PMA stimulation (p = 0.0004) and by 15% in response to SA (p = 0.36). HBOT showed an additive effect as growth reductions of 26% to sub-MICs of tobramycin (p = 0.0057), 44% to sub-MICs of ciprofloxacin (p = 0.0001), and 26% to sub-MICs of penicillin (p = 0.038). The present in vitro study provides evidence that HBOT has differential mechanisms mediating its anti-SA effects. Our observation supports the clinical possibility for adjunctive HBOT to augment the host immune response and optimize the efficacy of antibiotic treatments.

中文翻译：

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高压氧治疗对人类中性粒细胞功能和对金黄色葡萄球菌的抗生素功效的独特贡献

金黄色葡萄球菌(SA) 会导致浅表和严重的血管内感染。目前体外研究调查了高压氧疗法 (HBOT) 对直接细菌杀伤、抗生素增效和多形核白细胞 (PMN) 增强的抗 SA 机制。SA 暴露于分离的人类 PMN、妥布霉素、环丙沙星或苄青霉素。HBOT 被用作一个 90 分钟的会话。4 小时后通过定量细菌学评估细菌存活率。通过二氢罗丹明 123 分析测量作为活性氧 (ROS) 产生的 PMN 功能。我们表明 HBOT 表现出显着的直接抗 SA 作用。在 PMA 刺激后，HBOT 将 PMN 的抗 SA 作用提高了 18%（p = 0.0004），对 SA 的响应提高了 15%（p = 0.36）。HBOT 显示出累加效应，因为妥布霉素亚 MIC 的生长减少 26% (p = 0.0057)，环丙沙星亚 MIC 的生长减少 44% (p = 0.0001)，和 26% 的青霉素亚 MIC (p = 0.038)。现在的体外研究提供的证据表明 HBOT 具有介导其抗 SA 作用的不同机制。我们的观察结果支持辅助 HBOT 增强宿主免疫反应和优化抗生素治疗效果的临床可能性。