Infectious and Tropical Diseases Department, University Hospital of Bordeaux, Bordeaux, France.
USC EA 3671 Mycoplasmal and Chlamydial Infections in Humans, University Hospital of Bordeaux, French National Reference Centre for Bacterial STIs, Bordeaux, France; Bacteriology Department, University Hospital of Bordeaux, Bordeaux, France.
Eur J Vasc Endovasc Surg. 2018 Oct;56(4):562-571. doi: 10.1016/j.ejvs.2018.06.064. Epub 2018 Jul 31.
Vascular graft infections (VGIs) are severe and require prolonged adequate antimicrobial therapy. However, up to 45% of conventional cultures are negative. Sonication and genus specific PCRs for microbiological diagnosis of VGI was evaluated.
Samples were prospectively obtained from explanted vascular grafts in Bordeaux University Hospital. Conventional bacterial cultures with and without prior sonication of samples were performed. A genus specific PCR assay panel, targeting the most frequent bacteria involved in VGI (Staphylococcus, Streptococcus, Enterococcus, and Enterobacteriaceae), was also applied to sonicate fluids. The performance of these three diagnostic strategies was compared.
Forty-five patients (118 samples) were included between July 2014 and October 2015. Six patients had no infection and 39 had a VGI. Sensitivities of graft culture, sonicate fluid culture, and genus specific PCR were 85.7%, 89.7%, and 79.5%, respectively. Specificities were 100%, 100%, and 83.3%, respectively. Sonicate fluid culture was positive for five graft samples (from four patients) with negative culture without sonication. Four VGIs were detected by PCR only (3 patients had previously received antibiotics). For 15 patients with positive graft cultures, PCR identified at least one additional bacterium compared with culture, thus 30 additional bacteria for all included patients. By combining sonicate fluid culture and PCR, a microbiological diagnosis was obtained for all patients with VGI.
There was no statistical difference between performances of culture with and without sonication and genus specific PCR. However, combining sonicate fluid cultures and PCR may be the best strategy for microbiological diagnostic of VGI.
血管移植物感染（VGI）较为严重，需要长期使用适当的抗菌药物治疗。然而，高达 45%的常规培养结果呈阴性。本研究旨在评估超声处理和种特异性 PCR 在 VGI 微生物学诊断中的应用。
前瞻性收集波尔多大学医院的血管移植物样本。进行了有创和无创超声处理的常规细菌培养，以及针对 VGI 中最常见细菌（葡萄球菌属、链球菌属、肠球菌属和肠杆菌科）的种特异性 PCR 检测。比较了这三种诊断策略的性能。
2014 年 7 月至 2015 年 10 月，共纳入 45 例患者（118 个样本）。6 例患者无感染，39 例患者发生 VGI。移植物培养、超声处理液培养和种特异性 PCR 的灵敏度分别为 85.7%、89.7%和 79.5%，特异性分别为 100%、100%和 83.3%。超声处理液培养阳性的 5 个移植物样本（来自 4 例患者），培养阴性而未行超声处理。PCR 检测到 4 例 VGI，而这 4 例患者此前均接受过抗生素治疗。对于 15 例移植物培养阳性的患者，PCR 检测到的细菌种类比培养结果更多，因此，所有纳入患者共检出 30 种额外的细菌。将超声处理液培养和 PCR 相结合，可对所有 VGI 患者进行微生物学诊断。
超声处理和种特异性 PCR 与常规培养相比，其性能无统计学差异。然而，联合应用超声处理液培养和 PCR 可能是 VGI 微生物学诊断的最佳策略。
