Evaluation of a two-step approach for large-scale, prospective genotyping of Mycobacterium tuberculosis isolates in the United States
Evaluation of a two-step approach for large-scale, prospective genotyping of Mycobacterium tuberculosis isolates in the United States
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DOI：
10.1128/jcm.43.2.688-695.2005
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发表时间：
2005-02-01
影响因子：
9.4
通讯作者：
Crawford, JT
中科院分区：
文献类型：
--
作者：
Cowan, LS;Diem, L;Crawford, JT
结核分枝杆菌分离株的基因分型在结核病控制中是有用的，用于确认可疑的传播环节，识别非可疑的传播，以及检测或确认可能的假阳性培养物。通过缩短从阳性培养到基因分型结果的周转时间以及增加可获得结果的病例比例，可大大提高价值。尽管IS6110指纹图谱提供了最高的区分度，但基于扩增的方法允许快速、高通量处理，并产生易于分析的数字结果，因此更适合大规模基因分型。M.代表2000年至2003年在威斯康星州诊断的结核病培养阳性病例的99%的结核病分离株（n = 259）通过使用spoligotyping、分枝杆菌散布重复单位（MIRU）分型和IS 6110指纹法进行基因分型。Spoligotyping聚类率为64.1%，MIRU聚类率为46.7%，IS6110指纹图谱聚类率为29.7%。spoligotyping和MIRU分型的组合产生了184个独特的分离株和26个集群，其中包含75个分离株（29.0%）。如果需要精确的模式匹配，则添加IS6110指纹将聚类分离株的数量减少到30个（11.6%），如果扩展匹配IS6110指纹的定义以包括通过添加单个条带而不同的模式，则减少到44个（17.0%）。无论选择哪种基因分型方法，增加第二种或第三种方法都会减少聚类。我们的研究结果表明，使用spoligotyping和MIRU分型一起提供了足够的歧视，在大多数情况下。当需要额外的区分时，IS6110指纹法可以用作第二分型方法来分型聚类分离株。
Genotyping of Mycobacterium tuberculosis isolates is useful in tuberculosis control for confirming suspected transmission links, identifying unsuspected transmission, and detecting or confirming possible false-positive cultures. The value is greatly increased by reducing the turnaround time from positive culture to genotyping result and by increasing the proportion of cases for which results are available. Although IS6110 fingerprinting provides the highest discrimination, amplification-based methods allow rapid, high-throughput processing and yield digital results that can be readily analyzed and thus are better suited for large-scale genotyping. M. tuberculosis isolates (n = 259) representing 99% of culture-positive cases of tuberculosis diagnosed in Wisconsin in the years 2000 to 2003 were genotyped by using spoligotyping, mycobacterial interspersed repetitive unit (MIRU) typing, and IS6110 fingerprinting. Spoligotyping clustered 64.1% of the isolates, MIRU typing clustered 46.7% of the isolates, and IS6110 fingerprinting clustered 29.7% of the isolates. The combination of spoligotyping and MIRU typing yielded 184 unique isolates and 26 clusters containing 75 isolates (29.0%). The addition of IS6110 fingerprinting reduced the number of clustered isolates to 30 (11.6%) if an exact pattern match was required or to 44 (17.0%) if the definition of a matching IS6110 fingerprint was expanded to include patterns that differed by the addition of a single band. Regardless of the genotyping method chosen, the addition of a second or third method decreased clustering. Our results indicate that using spoligotyping and MIRU typing together provides adequate discrimination in most cases. IS6110 fingerprinting can then be used as a secondary typing method to type the clustered isolates when additional discrimination is needed.