Bidovec-Stojkovič Urška, Seme Katja, Žolnir-Dovč Manca, Supply Philip
Laboratory for Mycobacteria, University Clinic of Respiratory and Allergic Diseases, Golnik, Slovenia.
University of Ljubljana, Faculty of Medicine, Institute of Microbiology and Immunology, Ljubljana, Slovenia.
PLoS One. 2014 Oct 14;9(10):e109547. doi: 10.1371/journal.pone.0109547. eCollection 2014.
Shorter time-to-result is key for improving molecular-guided epidemiological investigation of tuberculosis (TB) cases. We performed a prospective study to evaluate the use of standardized MIRU-VNTR (mycobacterial interspersed repetitive-unit-variable-number tandem-repeat) typing of Mycobacterium tuberculosis directly on 79 fresh clinical samples from 26 TB patients consecutively enrolled over a 17-month period. Overall, complete 24-locus types were obtained for 18 out of the 26 (69.2%) patients and 14 of the 16 grade 3+ and grade 2+ samples (87.5%). The degree of completion of the genotypes obtained significantly correlated with smear microscopy grade both for 26 first samples (p = 0.0003) and for 53 follow-up samples (p = 0.002). For 20 of the 26 patients for whom complete or even incomplete M. tuberculosis isolate genotypes were obtained, typing applied to the clinical samples allowed the same unambiguous conclusions regarding case clustering or uniqueness as those that could have been drawn based on the corresponding cultured isolates. Standard 24 locus MIRU-VNTR typing of M. tuberculosis can be applied directly to fresh clinical samples, with typeability depending on the bacterial load in the sample.
缩短结果获取时间是改善结核病（TB）病例分子引导的流行病学调查的关键。我们进行了一项前瞻性研究，以评估直接对来自26例TB患者的79份新鲜临床样本进行标准化的结核分枝杆菌间隔重复单位可变数目串联重复序列（MIRU-VNTR）分型的应用情况。这些患者是在17个月期间连续纳入的。总体而言，26例患者中有18例（69.2%）以及16份3+级和2+级样本中的14份（87.5%）获得了完整的24位点分型。对于26份初次样本（p = 0.0003）和53份随访样本（p = 0.002），所获得基因型的完成程度均与涂片显微镜检查分级显著相关。对于26例患者中的20例，无论获得的结核分枝杆菌分离株基因型是完整的还是不完整的，对临床样本进行分型都能得出与基于相应培养分离株得出的关于病例聚集或独特性的相同明确结论。结核分枝杆菌的标准24位点MIRU-VNTR分型可直接应用于新鲜临床样本，分型成功率取决于样本中的细菌载量。
