Department of Biochemistry, School of Life and Environmental Science, Azabu University, Kanagawa, Japan.
Department of General Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan.
PLoS One. 2021 Feb 4;16(2):e0246002. doi: 10.1371/journal.pone.0246002. eCollection 2021.
Surgical site infections (SSIs) are significant and frequent perioperative complications, occurring due to the contamination of the surgical site. The late detection of SSIs, especially organ/space SSIs which are the more difficult to treat, often leads to severe complications. An effective method that can identify bacteria with a high accuracy, leading to the early detection of organ/space SSIs, is needed. Ninety-eight drainage fluid samples obtained from 22 patients with hepatobiliary pancreatic disease were analyzed to identify microorganisms using matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) with a new membrane filtration protocol and rapid BACpro® pretreatment compared to sole rapid BACpro® pretreatment. The levels of detail of rapid BACpro® pretreatment with or without filtration were also evaluated for the accuracy of bacterial identification. We found that reliable scores for E. coli and E. faecalis were obtained by inoculation with 1.0 × 104 CFU/ml after preparation of the membrane filter with rapid BACpro®, indicating approximately 10-folds more sensitive compared to sole rapid BACpro® pretreatment in drainage fluid specimens. Among 60 bacterial positive colonies in drainage fluid specimens, the MALDI-TOF MS and the membrane filtration with rapid BACpro® identified 53 isolates (88.3%) with a significantly higher accuracy, compared to 25 isolates in the rapid BACpro® pretreatment group (41.7%) (p < 0.001). Among the 78 strains, 14 enteric Gram-negative bacteria (93.0%) and 55 Gram-positive cocci (87.3%) were correctly identified by the membrane filtration with rapid BACpro® with a high reliability. This novel protocol could identify bacterial species within 30 min, at $2-$3 per sample, thus leading to cost and time savings. MALDI-TOF MS with membrane filter and rapid BACpro® is a quick and reliable method for bacterial identification in drainage fluids. The shortened analysis time will enable earlier selection of suitable antibiotics for treatment of organ/space SSIs to improve patients' outcomes.
手术部位感染（SSI）是一种重要且常见的围手术期并发症，是由于手术部位受到污染而引起的。SSI 往往很难治疗，特别是器官/腔隙 SSI 通常难以早期发现，这常常导致严重的并发症。因此，我们需要一种能够准确识别细菌的有效方法，从而早期发现器官/腔隙 SSI。
本研究采用基质辅助激光解吸电离飞行时间质谱（MALDI-TOF MS）技术，对 22 例肝胆胰疾病患者的 98 份引流液标本进行分析，与单独使用快速 BACpro®预处理相比，采用新的膜过滤方案和快速 BACpro®预处理来鉴定微生物。还评估了快速 BACpro®预处理是否结合过滤的详细程度对细菌鉴定的准确性。我们发现，使用快速 BACpro®制备膜过滤器后，以 1.0×104 CFU/ml 的接种量接种，可获得可靠的大肠杆菌和粪肠球菌评分，表明在引流液标本中的敏感性提高了约 10 倍。在 60 个细菌阳性菌落中，MALDI-TOF MS 和快速 BACpro®膜过滤法的鉴定准确率显著高于单独使用快速 BACpro®预处理组（p<0.001），前者鉴定出 53 株（88.3%），后者鉴定出 25 株（41.7%）。在 78 株菌中，膜过滤快速 BACpro®法可正确鉴定出 14 株肠杆菌革兰氏阴性菌（93.0%）和 55 株革兰氏阳性球菌（87.3%），具有较高的可靠性。该新方案可在 30 min 内鉴定出细菌种类，每个样本的成本和时间仅为 2-3 美元，从而节省了成本和时间。MALDI-TOF MS 结合膜过滤和快速 BACpro®是一种快速可靠的方法，用于鉴定引流液中的细菌。分析时间的缩短将有助于更早地选择合适的抗生素治疗器官/腔隙 SSI，从而改善患者的预后。
