Mycobacterium tuberculosis ecology in Venezuela: epidemiologic correlates of common spoligotypes and a large clonal cluster defined by MIRU-VNTR-24.
Mycobacterium tuberculosis ecology in Venezuela: epidemiologic correlates of common spoligotypes and a large clonal cluster defined by MIRU-VNTR-24.
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DOI：
10.1186/1471-2334-9-122
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发表时间：
2009-08-06
影响因子：
3.7
通讯作者：
Takiff HE
中科院分区：
文献类型：
--
作者：
Abadía E;Sequera M;Ortega D;Méndez MV;Escalona A;Da Mata O;Izarra E;Rojas Y;Jaspe R;Motiwala AS;Alland D;de Waard J;Takiff HE
结核病仍然是一个地方性公共卫生问题，但结核病流行菌株的生态及其传播可能因国家和地区而异。我们试图调查结核分枝杆菌菌株在委内瑞拉不同地区的流行情况。先前的一项研究确定了委内瑞拉最流行的菌株，但没有显示地理分布，也没有确定克隆基因型。为了更好地了解当地菌株生态，我们使用spoligotyping分析了1298 M。结核菌株分离在委内瑞拉1997年至2006年，主要来自两个大的城市中心和两个地理上不同的土著地区，然后研究了一个亚组MIRU-VNTR 24位点。Spoligotype家族的分布与以前报道的委内瑞拉和其他南美国家相似：LAM 53%，T 10%，哈勒姆5%，S 1.9%，X 1.2%，北京0.4%，和EAI 0.2%。6个最常见的共享型（SIT 17、93、605、42、53、20）占分离株的49%，几乎在所有地区都是最常见的，但只有少数被MIRU-VNTR 24聚类。一个例外是第三个最常见的整体，SIT 605，这是最常见的spoligotype在卡拉博博州，但在其他地区不常见。MIRU-VNTR同源性表明它是一个克隆组的菌株，并被命名为“卡拉博博”基因型。流行病学比较显示，SIT 17的患者更年轻，更可能在显微镜下有抗酸杆菌阳性标本，而SIT 53的患者年龄较大，更常见涂片阴性。女性结核病患者往往比男性患者年轻。来自Delta Amacuro州高发病率土著人群的患者更年轻，男性：女性分布几乎相等。六种SIT导致委内瑞拉近一半的结核病病例，并在几乎所有地区占主导地位。具有SIT 17的菌株，总体上最常见的模式可能更活跃地传播，而SIT 53菌株可能毒性较低，并且与老年患者中既往感染的再激活有关。与其他常见的spoligotypes相反，具有SIT 605的菌株形成以卡拉博博州为中心的克隆群。
Tuberculosis remains an endemic public health problem, but the ecology of the TB strains prevalent, and their transmission, can vary by country and by region. We sought to investigate the prevalence of Mycobacterium tuberculosis strains in different regions of Venezuela. A previous study identified the most prevalent strains in Venezuela but did not show geographical distribution nor identify clonal genotypes. To better understand local strain ecology, we used spoligotyping to analyze 1298 M. tuberculosis strains isolated in Venezuela from 1997 to 2006, predominantly from two large urban centers and two geographically distinct indigenous areas, and then studied a subgroup with MIRU-VNTR 24 loci. The distribution of spoligotype families is similar to that previously reported for Venezuela and other South American countries: LAM 53%, T 10%, Haarlem 5%, S 1.9%, X 1.2%, Beijing 0.4%, and EAI 0.2%. The six most common shared types (SIT's 17, 93, 605, 42, 53, 20) accounted for 49% of the isolates and were the most common in almost all regions, but only a minority were clustered by MIRU-VNTR 24. One exception was the third most frequent overall, SIT 605, which is the most common spoligotype in the state of Carabobo but infrequent in other regions. MIRU-VNTR homogeneity suggests it is a clonal group of strains and was named the "Carabobo" genotype. Epidemiologic comparisons showed that patients with SIT 17 were younger and more likely to have had specimens positive for Acid Fast Bacilli on microscopy, and patients with SIT 53 were older and more commonly smear negative. Female TB patients tended to be younger than male patients. Patients from the high incidence, indigenous population in Delta Amacuro state were younger and had a nearly equal male:female distribution. Six SIT's cause nearly half of the cases of tuberculosis in Venezuela and dominate in nearly all regions. Strains with SIT 17, the most common pattern overall may be more actively transmitted and SIT 53 strains may be less virulent and associated with reactivation of past infections in older patients. In contrast to other common spoligotypes, strains with SIT 605 form a clonal group centered in the state of Carabobo.