Microbiology Unit, Laboratory Diagnosis Service, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
InfectiousDiseases Unit, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
Biomed Res Int. 2019 Oct 3;2019:8041746. doi: 10.1155/2019/8041746. eCollection 2019.
We evaluated a rapid bacterial identification (rID) and a rapid antimicrobial susceptibility testing by disk diffusion (rAST) from positive blood culture to overcome the limitations of the conventional methods and reduce the turnaround time in bloodstream infection diagnostics. The study included hemocultures flagged as positive by bacT/ALERT®, identification by MALDI-TOF MS, and rAST. The results were compared to identification and antimicrobial susceptibility testing (AST) results by current standard methods, after 24 h incubation. For rAST categorical agreement (CA), very major errors (VME), major errors (ME), and minor errors (mE) were calculated. A total of 524 bacterial samples isolated from blood cultures were obtained, including 246 Gram-negative (GN) and 278 Gram-positive (GP) aerobes. The overall concordance of rID was 88.6%, and it was highest among GN (96%). A total of 2196 and 1476 antimicrobial agent comparisons were obtained for GN and GP, respectively. Evaluation of rAST, CA, VME, ME, and mE disclosed 97.7, 0.7, 0.5, and 1.1% for GN and 98.0, 0.5, 0.7, and 0.8% for GP, respectively. Meropenem CA, VME, and ME were 98.3, 0.5, and 0.5%, respectively; mE was not observed. Oxacillin CA, ME, and mE were 97.4, 1.6, and 0.6%, respectively; VME was not observed. Overall, kappa scores of the results of the comparisons demonstrated the high agreement between rAST and the standard method. Identification and AST of aerobic bacteria from positive blood cultures after a short period of incubation on solid blood agar is a fast and reliable method that may improve the management of bloodstream infections.
我们评估了一种快速细菌鉴定（rID）和一种快速药敏试验（rAST），方法是从阳性血培养物中进行平板扩散，以克服传统方法的局限性，并缩短血流感染诊断的周转时间。该研究包括由 bacT/ALERT®标记为阳性的血培养物、MALDI-TOF MS 鉴定和 rAST。结果与孵育 24 小时后的当前标准方法的鉴定和药敏试验（AST）结果进行比较。对于 rAST 的分类一致性（CA）、非常大错误（VME）、主要错误（ME）和次要错误（mE）进行了计算。共获得 524 株从血培养物中分离的细菌样本，包括 246 株革兰氏阴性（GN）和 278 株革兰氏阳性（GP）需氧菌。rID 的总一致性为 88.6%，在 GN 中最高（96%）。分别获得了 2196 和 1476 种抗微生物药物比较，用于 GN 和 GP。rAST 的评估，CA、VME、ME 和 mE 分别为 GN 的 97.7%、0.7%、0.5%和 1.1%和 GP 的 98.0%、0.5%、0.7%和 0.8%。美罗培南的 CA、VME 和 ME 分别为 98.3%、0.5%和 0.5%；未观察到 mE。苯唑西林的 CA、ME 和 mE 分别为 97.4%、1.6%和 0.6%；未观察到 VME。总体而言，结果比较的 Kappa 评分表明 rAST 和标准方法之间具有高度一致性。在固体血琼脂上短时间孵育后从阳性血培养物中鉴定和 AST 鉴定需氧菌是一种快速可靠的方法，可能改善血流感染的管理。
