血流感染与高死亡率相关,在感染的早期阶段可以通过靶向抗生素治疗来减少。来自标记阳性血液培养物的直接抗生素敏感性测试(AST)可能有助于在常规AST之前施用早期有效的抗微生物剂。这项研究旨在评估来自标记的阳性血液培养肉汤的革兰氏阴性棒的三种不同的直接AST方案。通过临床和实验室标准研究所推荐的直接圆盘扩散(方案A),将仅显示革兰氏阴性棒的血培养肉汤进行直接AST。此外,使用标准接种物进行自动化AST(方案B)和Kirby-Bauer圆盘扩散(方案C),所述标准接种物由通过在血清分离小瓶中离心血液培养培养液获得的细菌沉淀制备。为了比较,来自固体培养基继代培养的分离物的常规AST也用Kirby-Bauer圆盘扩散(参考标准)和自动化方法进行。总的来说,议定书A的明确协议,B,C为97.6%,95.7%,和95.9%,分别。在肠杆菌中,小错误,主要错误,方案B的主要错误率为3.5%,0.36%,和0.43%,分别,而小错误,主要错误,方案C的主要错误率为3.4%,0.72%,和0.21%,分别,在非发酵罐中,方案B的轻微错误率为6.5%,方案C的轻微错误率为4.1%,主要错误率为1.9%。所有三个直接AST协议都显示出与参考方法的出色分类协议。肠杆菌和非发酵罐之间的方案B和C的性能没有统计学差异。
目的:血流感染与高死亡率相关,可在感染早期通过靶向抗生素治疗降低死亡率。来自标记阳性血液培养物的直接抗生素敏感性测试(AST)可能有助于在常规AST之前施用早期有效的抗微生物剂。临床和实验室标准研究所推荐的直接AST只能用有限数量的抗生素盘进行。另一方面,使用直接AST的自动化系统不仅可以减少周转时间的有效实验室工作流程,还可以提供测试抗生素的最低抑制浓度值。然而,对于资源有限的实验室,使用昂贵的自动化系统进行直接AST可能不可行。因此,在这项研究中,我们旨在评估CLSI推荐的方法和另外两种直接AST方案(一种采用自动化系统,另一种采用圆盘扩散)对标记阳性血培养物的革兰氏阴性棒的评价.
Bloodstream infections are associated with high mortality, which can be reduced by targeted antibiotic therapy in the early stages of infection.
Direct antibiotic susceptibility testing (AST) from flagged positive blood cultures may facilitate the administration of early effective antimicrobials much before the routine AST. This study aimed to evaluate three different
direct AST protocols for Gram-negative rods from flagged positive blood culture broths. Blood culture broths showing Gram-negative rods only were subjected to direct AST by Clinical and Laboratory Standards Institute-recommended
direct disk diffusion (protocol A). Additionally, automated AST (protocol B) and Kirby-Bauer disk diffusion (protocol C) were performed with standard inoculum prepared from bacterial pellets obtained by centrifuging blood culture broths in serum separator vials. For comparison, conventional AST of isolates from solid media subculture was also performed with Kirby-Bauer disk diffusion (reference standard) and the automated method. Overall, categorical agreements of protocols A, B, and C were 97.6%, 95.7%, and 95.9%, respectively. Among Enterobacterales, minor error, major error, and very major error rates of protocol B were 3.5%, 0.36%, and 0.43%, respectively, whereas minor error, major error, and very major error rates of protocol C were 3.4%, 0.72%, and 0.21%, respectively, and among non-fermenters, protocol B had a minor error rate of 6.5%, and protocol C had a minor error rate of 4.1% and major error rate of 1.9%. All three
direct AST protocols demonstrated excellent categorical agreements with the reference method. Performance of protocols B and C between Enterobacterales and non-fermenters was not statistically different.
OBJECTIVE: Bloodstream infections are associated with high mortality that can be reduced by targeted antibiotic therapy in the early stages of infection.
Direct antibiotic susceptibility testing (AST) from flagged positive blood cultures may facilitate the administration of early effective antimicrobials much before the routine AST. Clinical and Laboratory Standards Institute-recommended direct AST can be performed with a limited number of antibiotic disks only. On the other hand, using an automated system for
direct AST will not only allow effective laboratory workflow with reduced turnaround time but also provide the minimum inhibitory concentration values of tested antibiotics. However, using expensive automated systems for direct AST may not be feasible for resource-limited laboratories. Therefore, in this study, we aimed to evaluate the CLSI-recommended method and two other direct AST protocols (one with an automated system and the other with disk diffusion) for Gram-negative rods from flagged positive blood cultures.