Streit Elisabeth, Baboolal Shirematee, Akpaka Patrick E, Millet Julie, Rastogi Nalin
WHO Supranational TB Reference Laboratory, Unité de la Tuberculose et des Mycobactéries, Institut Pasteur de Guadeloupe, Abymes Cedex, Guadeloupe.
Department of Para-Clinical Sciences, Faculty of Medical Sciences, The University of the West Indies, St. Augustine, Trinidad and Tobago.
Infect Genet Evol. 2015 Mar;30:114-119. doi: 10.1016/j.meegid.2014.12.015. Epub 2014 Dec 17.
In this study we used spoligotyping and 15-loci MIRU-VNTRs for a finer characterization of Mycobacterium tuberculosis strains isolated from patients residing in Guyana (n=74) and Suriname (n=80). The mean age of the patients was 38.5years (36.5 and 40.2years for Guyana vs. Suriname), with a male-to-female sex-ratio of 2.25 for Guyana vs. 4.27 in Suriname. Spoligotyping and 15-loci MIRU-VNTRs led to a total of 41 and 65 different patterns respectively, with an overall clustering rate of 83.8% vs. 68.8%. Combined spoligotyping and VNTR analysis led to the detection of 18 clusters of 2-41 isolates, with an overall clustering of 67.5% and a recent "n-1" transmission rate of 55.8%. Importantly, Guyana was characterized by a significantly higher percentage of clustered isolates than Suriname (79.7% vs. 56.3%; p=0.0019). Three big spoligo/MIRU (SIT/MIT) clusters containing >10 isolates each were shared between the 2 countries, and concerned: T1 sublineage cluster 53/861 (n=41, 37 in Guyana vs. 4 in Suriname); EAI6-BGD1 sublineage cluster 1340/860 (n=16, 3 in Guyana vs. 13 in Suriname); and T1 sublineage cluster 131/146 (n=11, 6 in Guyana vs. 5 in Suriname); as well as 2 smaller clusters of 2 and 3 isolates respectively. However, the relative phylogeographical specificities of strains in circulation as well as a lack of drug-resistance observed among strains from Suriname suggested that trans-border transmission of drug-resistant isolates occurred less frequently than thought. Tracing and interrupting transmission channels of a specific clone (SIT53/15-MIT861) should become a priority in Guyana, not only because it is by far most abundant but also because it accounts for almost half of the drug resistant isolates (n=8/17, 47.1%) in our study, and clustered 5/12 (41.7%) MDR isolates.
在本研究中，我们使用间隔寡核苷酸分型（spoligotyping）和15个位点的多位点可变数目串联重复序列分析（MIRU-VNTRs），对从圭亚那（n = 74）和苏里南（n = 80）患者中分离出的结核分枝杆菌菌株进行更精细的特征分析。患者的平均年龄为38.5岁（圭亚那为36.5岁，苏里南为40.2岁），圭亚那的男女比例为2.25，而苏里南为4.27。间隔寡核苷酸分型和15个位点的MIRU-VNTRs分别产生了总共41种和65种不同的模式，总体聚类率分别为83.8%和68.8%。间隔寡核苷酸分型和VNTR联合分析检测到18个由2至41株菌株组成的聚类，总体聚类率为67.5%，近期“n - 1”传播率为55.8%。重要的是，圭亚那的聚类菌株百分比显著高于苏里南（79.7%对56.3%；p = 0.0019）。两国共有3个大型间隔寡核苷酸分型/ MIRU（SIT / MIT）聚类，每个聚类包含超过10株菌株，分别为：T1亚系聚类53/861（n = 41，圭亚那37株，苏里南4株）；EAI6 - BGD1亚系聚类1340/860（n = 16，圭亚那3株，苏里南13株）；以及T1亚系聚类131/146（n = 11，圭亚那6株，苏里南5株）；还有2个分别由2株和3株菌株组成的较小聚类。然而，流行菌株的相对系统地理特异性以及在苏里南菌株中未观察到耐药性，表明耐药菌株的跨境传播比想象的要少。追踪和阻断特定克隆（SIT53/15 - MIT861）的传播途径应成为圭亚那的优先事项，这不仅是因为它是目前最常见的，还因为在我们的研究中它占耐药菌株的近一半（n = 8/17，47.1%），并且聚集了5/12（41.7%）的耐多药菌株。
