Chen Xiao-Li, Zheng Hao, Li Wen-Ge, Zhong You-Hong, Chen Xiao-Ping, Lu Jin-Xing
National Institute for Communicable Disease Control and Prevention, State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, China.
Yunnan Provincial Key Laboratory for Zoonosis Control and Prevention, Yunnan Institute for Endemic Disease Control and Prevention, Dali, China.
J Clin Microbiol. 2020 Mar 25;58(4). doi: 10.1128/JCM.00057-20.
A rapid and accurate method to identify the species and antibiotic resistance of spp. in blood is vital to increase the survival rates of patients with bloodstream infections. However, the extremely low levels of spp. in blood make rapid diagnosis by standard blood culture difficult. In this study, we constructed a direct blood culturing method (i.e., the M1 method) by a rapid enrichment method with magnetic beads coated with a recombined human mannan-binding lectin (rhMBL; i.e., M1 protein), which demonstrated much higher sp.-binding capacity than that of full-length MBL expressed (i.e., M2). With the M1 method, individual colonies were obtained before the standard blood culture method for each species of spp. tested at <1 CFU/ml (an average of 29 h earlier). Additionally, the clinical sensitivity of the M1 method was 90.5% compared with that of the standard blood culture method when detecting frozen plasma from patients. More significantly, the turnaround time of the M1 method for blood culture could be reduced by approximately 37 to 43 h compared with that of the standard blood culture method in clinical sample identification.
一种快速准确地鉴定血液中某菌属的种类及抗生素耐药性的方法对于提高血流感染患者的存活率至关重要。然而，血液中某菌属的含量极低，使得通过标准血培养进行快速诊断变得困难。在本研究中，我们通过用重组人甘露聚糖结合凝集素（rhMBL；即M1蛋白）包被的磁珠进行快速富集法构建了一种直接血培养方法（即M1方法），该方法显示出比表达的全长MBL（即M2）更高的某菌属结合能力。使用M1方法，在对每种测试的某菌属在<1 CFU/ml时，比标准血培养方法更早获得单个菌落（平均早29小时）。此外，在检测患者的冷冻血浆时，M1方法与标准血培养方法相比临床敏感性为90.5%。更显著的是，在临床样本鉴定中，与标准血培养方法相比，M1方法的血培养周转时间可减少约37至43小时。
