Metabolomic Analysis of Polymicrobial Wound Infections and an Associated Adhesive Bandage

Concerns about ion suppression, spectral contamination, or interference have led to avoidance of polymers in mass spectrometry (MS)-based metabolomics. This avoidance, however, has left many biochemical fields underexplored, including wounds, which are often treated with adhesive bandages. Here, we found that despite previous concerns, the addition of an adhesive bandage can still result in biologically informative MS data. Initially, a test LC-MS analysis was performed on a mixture of known chemical standards and a polymer bandage extract. Results demonstrated successful removal of many polymer-associated features through a data processing step. Furthermore, the bandage presence did not interfere with metabolite annotation. This method was then implemented in the context of murine surgical wound infections covered with an adhesive bandage and inoculated with Staphylococcus aureus, Pseudomonas aeruginosa, or a 1:1 mix of these pathogens. Metabolites were extracted and analyzed by LC-MS. On the bandage side, we observed a greater impact of infection on the metabolome. Distance analysis showed significant differences between all conditions and demonstrated that coinfected samples were more similar to S. aureus-infected samples compared to P. aeruginosa-infected samples. We also found that coinfection was not merely a summative effect of each monoinfection. Overall, these results represent an expansion of LC-MS-based metabolomics to a novel, previously under-investigated class of samples, leading to actionable biological information.由于对离子抑制、光谱污染或干扰的担忧，基于质谱（MS）的代谢组学研究一直避免使用聚合物材料。然而，这种规避策略使得包括伤口在内的诸多生化研究领域未能得到充分探索——而伤口临床常使用粘性绷带进行处理。本研究发现，尽管存在此前的顾虑，添加粘性绷带仍可获得具备生物学信息价值的质谱数据。研究初始阶段，我们对已知化学标准品与聚合物绷带提取物的混合样本开展了液相色谱-质谱（LC-MS）预分析，结果显示通过数据处理步骤可有效去除多数与聚合物相关的质谱特征峰。此外，绷带的存在并未干扰代谢物注释流程。随后，我们将该方法应用于使用粘性绷带覆盖并接种金黄色葡萄球菌（Staphylococcus aureus）、铜绿假单胞菌（Pseudomonas aeruginosa）或二者1:1混合菌液的小鼠手术伤口感染模型。通过液相色谱-质谱（LC-MS）对提取的代谢物进行分析后，我们观察到绷带侧样本的代谢组受感染的影响更为显著。距离分析结果显示，所有实验组间均存在显著差异，且与铜绿假单胞菌感染样本相比，共感染样本的代谢谱更接近于金黄色葡萄球菌感染样本。同时我们发现，共感染的代谢组变化并非单一菌种感染效应的简单叠加。综上，本研究将基于液相色谱-质谱的代谢组学研究拓展至一类此前未被充分探索的新型样本类型，可产出具有实际应用价值的生物学信息。