Semiautomation of Multilocus Sequence Typing for the Characterization of Clinical Isolates of Neisseria meningitidis

The Scottish Meningococcus and Pneumococcus Reference Laboratory (SMPRL) provides a national service for the laboratory confirmation of meningococcal and pneumococcal disease in Scotland. Part of this service includes the serogrouping of meningococcal isolates followed by typing and subtyping. The procedures for this are labor-intensive but important for the identification of linked cases and the surveillance of disease so that effective public health measures can be taken. However, different strains of meningococci, such as those within the electrophoretic type 37 complex, occurring during case clusters of disease are now indistinguishable by current methods. The SMPRL has started using multilocus sequence typing (MLST) as a routine method for the characterization of isolates of Neisseria meningitidis. MLST produces nucleotide sequence data of seven housekeeping genes providing results that are useful for public health management. However, the method is laborious and time-consuming and therefore lends itself towards automation. The SMPRL therefore developed a semiautomated method for MLST using a 96-well format liquid handler and an automated DNA sequencer. Semiautomated MLST is now provided as a reference service for Scotland. This work describes the methodology required for the characterization of N. meningitidis and highlights its usefulness for public health intervention.

苏格兰脑膜炎球菌与肺炎球菌参考实验室（Scottish Meningococcus and Pneumococcus Reference Laboratory, SMPRL）可为苏格兰地区的脑膜炎球菌及肺炎球菌疾病提供实验室确诊的国家级服务。该服务的工作内容包括对脑膜炎球菌分离株进行血清群分型，随后开展分型与亚型分型检测。此类操作流程劳动强度较高，但对于关联病例识别与疾病监测至关重要，可支撑有效公共卫生防控措施的制定与实施。然而当前现有方法无法区分疾病暴发集群中出现的不同脑膜炎球菌菌株，例如电泳型37复合群内的菌株。为此，SMPRL已将多位点序列分型（multilocus sequence typing, MLST）作为脑膜炎奈瑟氏菌（Neisseria meningitidis）分离株特征鉴定的常规方法。MLST可生成7个管家基因的核苷酸序列数据，其结果对公共卫生管理具有重要参考价值。但该方法操作繁琐且耗时，因此适配自动化改造。基于此，SMPRL开发了一套采用96孔板液体处理工作站与自动化DNA测序仪的半自动化MLST检测方案。目前半自动化MLST已作为苏格兰地区的参考检测服务对外提供。本研究阐述了脑膜炎奈瑟氏菌特征鉴定所需的方法学流程，并强调了其在公共卫生干预中的应用价值。