Bioburden Predictors of Diabetic Ulcer Complications

描述（由申请人提供）：很难确定糖尿病足溃疡（DFU）是否会导致感染相关并发症。本申请的目的是制定策略，以准确识别可能发生感染相关并发症的DFU。目的是：1）确定a）高微生物负荷、B）微生物多样性和c）金黄色葡萄球菌和厌氧菌（基于使用Levine技术获得的拭子培养物）在预测无临床感染体征的糖尿病足溃疡中的感染相关并发症方面的预后功效;和2）确定组合微生物学维度将在何种程度上提高超过任何单一维度的预测能力。将采用前瞻性研究设计观察DFU在伤口闭合前的感染相关并发症。将对150例有DFU但无临床感染体征的受试者样本进行伤口生物负载评估，并每两周随访一次感染相关并发症，直至1）伤口闭合，2）DFU相关截肢，3）失访或4）6个月数据收集结束。伤口生物负载有三个方面：微生物负载、微生物多样性和是否存在有毒微生物。将通过使用Levine技术获得的拭子样本定量培养来测量每个尺寸。Levine技术从深层组织层中采集液体样本，与伤口组织培养物相比，已被证明是伤口生物负载的有效测量方法。在每次随访期间，将收集伤口生物负载的重复测量值。此外，将在随访期间评估伤口恶化、骨髓炎或截肢的结局。ROC分析将用于评价ROC曲线下面积（AUC）方面的预后疗效。将考虑两种结局：（a）伤口闭合前伤口恶化和/或骨髓炎的发展，和（B）伤口闭合前截肢。将使用多变量逻辑回归开发复合预测因子。这项研究的结果将改善DFU风险的区分，从那些没有发展并发症的风险。通过这种方式，资源可以更有成本效益地用于患者，对他们来说，更有力的干预可以防止不良后果。

DESCRIPTION (provided by applicant): It is difficult to identify diabetic foot ulcers (DFU) destined for infection-related complications. The objective of this application is to develop strategies to accurately identify DFUs that are likely to proceed to develop infection-related complications. The aims are to 1) determine the prognostic efficacy of a) high microbial load, b) microbial diversity, and c) Staphylococcus aureus and anaerobes based on swab cultures obtained using Levine's technique in predicting infection-related complications among diabetic foot ulcers without signs of clinical infection; and 2) Determine the extent to which combining microbiological dimensions will improve the predictive ability above any single dimension. A prospective research design will be used to observe infection-related complications among DFUs before wound closure. A sample of 150 subjects with DFUs but without signs of clinical infection will be assessed for wound bioburden and followed for infection-related complications every two weeks until 1) wound closure, 2) DFU-related amputation, 3) loss to follow-up or 4) the end of six months of data collection. Wound bioburden has three dimensions: microbial load, microbial diversity, and presence of virulent organisms. Each dimension will be measured by quantitatively culturing swab specimens obtained using Levine's technique. Levine's technique samples fluid from deep tissue layers and has been shown to be a valid measure of wound bioburden when compared to cultures of wound tissue. Repeat measures of wound bioburden will be collected during each follow-up. In addition, the outcomes of wound deterioration, osteomyelitis, or amputation will be assessed during follow-up. ROC analysis will be used to evaluate the prognostic efficacy in terms of area under the ROC curve (AUC). Two outcomes will be considered: (a) the development of wound deterioration and/or osteomyelitis before wound closure, and (b) amputation before wound closure. A composite predictor will be developed using multivariable logistic regression. The findings from this research will improve the discrimination of DFUs at-risk from those not-at-risk for developing complications. In this way, resources can be more cost efficiently directed toward patients for whom more vigorous interventions can prevent undesirable outcomes.