快速确定细菌抗生素敏感性对于正确治疗感染很重要。欧洲抗菌药物敏感性试验委员会(EUCAST)最近发布了直接从阳性血培养瓶进行快速抗菌药物敏感性试验(RAST)的指南。这些准则,然而,仅针对有限数量的常见致病菌发表。在这项研究中,我们评估了这些指南对三种一级生物恐怖剂(炭疽杆菌,鼠疫耶尔森氏菌和土伦弗朗西斯氏菌)需要及时的抗生素治疗以减轻发病率和死亡率。我们使用在BACTEC™FX40系统中孵育的加标人血来确定使用圆盘扩散和Etest测定的RAST的适当条件。我们发现,可以在很短的时间内获得可靠的椎间盘扩散抑制直径和EtestMIC值。与EUCAST推荐的椎间盘扩散测定相比,需要调整临床断点表,基于Etest的RAST是有利的,由于获得的MIC值与标准MIC值相似,启用已建立的类别断点表的使用。我们的结果证明了EUCASTRAST对炭疽杆菌的有希望的适用性-,鼠疫菌或土拉灵弧菌血培养阳性,这可能导致更短的诊断和提示抗生素治疗这些危险的病原体。
Rapid determination of bacterial antibiotic susceptibility is important for proper treatment of infections. The European Committee on Antimicrobial Susceptibility Testing (EUCAST) has recently published
guidelines for rapid antimicrobial susceptibility testing (RAST) performed directly from positive blood culture vials. These
guidelines, however, were only published for a limited number of common pathogenic bacteria. In this study, we evaluated the applicability of these
guidelines to three Tier 1 bioterror agents (Bacillus anthracis, Yersinia pestis and Francisella tularensis) that require prompt antibiotic treatment to mitigate morbidity and mortality. We used spiked-in human blood incubated in a BACTEC™ FX40 system to determine the proper conditions for RAST using disc-diffusion and Etest assays. We found that reliable disc-diffusion inhibition diameters and Etest MIC values could be obtained in remarkably short times. Compared to the EUCAST-recommended disc-diffusion assays that will require adjusted clinical breakpoint tables, Etest-based RAST was advantageous, as the obtained MIC values were similar to the standard MIC values, enabling the use of established category breakpoint tables. Our results demonstrate the promising applicability of the EUCAST RAST for B. anthracis-, Y. pestis- or F. tularensis-positive blood cultures, which can lead to shorter diagnostics and prompt antibiotic treatment of these dangerous pathogens.