Alfred 60/AST（Alifax®）在多地点实验室中的抗菌药物敏感性测试：性能评估和工作流程优化。
Antimicrobial susceptibility testing determined by Alfred 60/AST (Alifax®) in a multi-sites lab: performance's evaluation and optimization of workflow.
机构信息
Microbiology Department, Laboratoire Hospitalier Universitaire de Bruxelles - Universitair Laboratorium Brussel (LHUB-ULB), Université Libre de Bruxelles, Brussels, Belgium.
Microbiology Department, Laboratoire Hospitalier Universitaire de Bruxelles - Universitair Laboratorium Brussel (LHUB-ULB), Université Libre de Bruxelles, Brussels, Belgium.
出版信息
J Microbiol Methods. 2022 Mar;194:106433. doi: 10.1016/j.mimet.2022.106433. Epub 2022 Feb 9.
PURPOSE
New techniques are needed to speed-up the identification and antimicrobial susceptibility testing (AST) of bacteria associated with bloodstream infections. Alfred 60/AST (Alifax®, Polverara, Italy) performs AST by light scattering directly from positive blood cultures.
METHODS
We evaluated Alfred 60/AST performances for 4 months. Each new episode of bacteraemia was included and AST were compared to either our rapid automated AST (Vitek® 2) or disk diffusion method. The discrepancies were investigated using Etest®. The time-to-result (TTR) was evaluated by comparing the blood volume inserted into Alfred 60/AST, i.e. 2 versus 7 blood drops. Taking into account the TTR, the workflow of positive blood cultures and the availability of AST results was studied in order to optimize the implementation of Alfred 60/AST.
RESULTS
A total of 249 samples and 1108 antibiotics for AST were tested. After exclusion of unavailable results, 1008 antibiotics were analysed. 94.9% (n = 957/1008) of the antibiotics showed categorical agreement. There were 14 very major errors (VME), 24 major errors (ME) and 13 minor errors (mE). The VME were mostly related to clindamycin (64.3%) whereas meropenem and piperacillin-tazobactam constituted the major part (37.5% and 61.5%) of ME and mE respectively. Results were highly reliable for Enterobacterales and enterococci. The mean TTR ranged between 4.3 and 6.3 h and was statistically 20 min faster when applying the 7 blood drops protocol. We showed that Alfred 60/AST could give relievable results within working hours for positive blood culture which are flagged the same day between 12:00 am and 12:00 pm.
CONCLUSION
Our study confirmed that Alfred 60/AST gives reliable AST results in a short period of time, especially for Enterobacterales and enterococci. AST could thus be easily obtained the same day of a positive blood culture. Clinical impact studies are mandatory to validate a 24/24 working.
目的
需要新的技术来加快与血流感染相关细菌的鉴定和药敏试验（AST）。Alfred 60/AST（Alifax®，Polverara，意大利）通过直接从阳性血培养物中散射光线来进行 AST。
方法
我们评估了 Alfred 60/AST 进行了 4 个月的性能。每个新的菌血症发作都被包括在内，AST 与我们的快速自动化 AST（Vitek®2）或纸片扩散法进行比较。使用 Etest® 对差异进行了调查。通过比较插入 Alfred 60/AST 的血量，即 2 与 7 滴血，评估了结果时间（TTR）。考虑到 TTR，研究了阳性血培养物的工作流程和 AST 结果的可用性，以优化 Alfred 60/AST 的实施。
结果
共测试了 249 份样本和 1108 种 AST 抗生素。排除不可用结果后，分析了 1008 种抗生素。94.9%（n=957/1008）的抗生素显示出分类一致。有 14 个非常大的错误（VME），24 个主要错误（ME）和 13 个次要错误（mE）。VME 主要与克林霉素有关（64.3%），而美罗培南和哌拉西林他唑巴坦分别构成 ME 和 mE 的主要部分（37.5%和 61.5%）。结果对肠杆菌科和肠球菌高度可靠。平均 TTR 范围在 4.3 到 6.3 小时之间，当应用 7 滴血方案时，统计学上快 20 分钟。我们表明，Alfred 60/AST 可以在工作时间内为阳性血培养物提供可靠的结果，这些结果在当天上午 12:00 至下午 12:00 之间标记为同一时间。
结论
我们的研究证实，Alfred 60/AST 可以在短时间内提供可靠的 AST 结果，特别是对肠杆菌科和肠球菌。因此，AST 可以在阳性血培养物的同一天轻松获得。需要进行临床影响研究来验证 24/24 小时工作。
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