Núcleo de Doenças Infecciosas, Universidade Federal do Espírito Santo, Av. Marechal Campos, 1468 Maruípe, Vitória, ES, Brazil.
Tuberculosis (Edinb). 2013 Mar;93(2):207-12. doi: 10.1016/j.tube.2012.09.001. Epub 2012 Dec 8.
Mycobacterium tuberculosis (Mtb) strains designated as RD(Rio) are responsible for a large cluster of new cases of tuberculosis (TB) in Rio de Janeiro. They were previously shown to be associated with severe manifestations of TB. Here, we used three genotyping methods (IS6110 RFLP, spoligotyping, and multiplex PCR) to characterize RD(Rio) and non-RD(Rio) strains from the metropolitan area of Vitória, State of Espirito Santo in southeast Brazil to determine strain diversity and transmission patterns. Strains with identical IS6110 RFLP patterns were considered to belong to a cluster indicative of recent transmission. Between 2000 and 2010, we identified 5470 new TB patients and genotyped 981 Mtb strains. Of these, 376 (38%) were RD(Rio). By RFLP, 180 (48%) of 376 RD(Rio) strains and 235 (40%) of 593 non-RD(Rio) strains belonged to RFLP cluster pattern groups (p = 0.023). Simpson's diversity index based on RFLP patterns was 0.96 for RD(Rio) and 0.98 for non-RD(Rio) strains. Thus, although RD(Rio) strains appear to be comprised of a fewer number of RFLP genotypes, they represent a heterogeneous group. While TB cases caused by RD(Rio) appear more likely to be due to recent transmission than cases caused by non-RD(Rio) strains, the difference is small. These observations suggest that factors other than inherent biological characteristic of RD(Rio) lineages are more important in determining recent transmission, and that public health measures to interrupt new transmissions need to be emphasized for TB control in Vitória.
结核分枝杆菌（Mtb）菌株被指定为 RD（里约热内卢），是里约热内卢大量新结核病（TB）病例的罪魁祸首。此前已证明它们与结核病的严重表现有关。在这里，我们使用三种基因分型方法（IS6110 RFLP、 spoligotyping 和多重 PCR）来表征来自巴西东南部圣埃斯皮里图州维多利亚大都市区的 RD（里约热内卢）和非 RD（里约热内卢）菌株，以确定菌株多样性和传播模式。具有相同 IS6110 RFLP 模式的菌株被认为属于近期传播的集群。在 2000 年至 2010 年间，我们确定了 5470 例新的结核病患者，并对 981 株 Mtb 菌株进行了基因分型。其中，376 株（38%）为 RD（里约热内卢）。通过 RFLP，376 株 RD（里约热内卢）菌株中的 180 株（48%）和 593 株非 RD（里约热内卢）菌株中的 235 株（40%）属于 RFLP 聚类模式群（p=0.023）。基于 RFLP 模式的辛普森多样性指数分别为 RD（里约热内卢）菌株的 0.96 和非 RD（里约热内卢）菌株的 0.98。因此，尽管 RD（里约热内卢）菌株似乎包含较少数量的 RFLP 基因型，但它们代表了一个异质群体。虽然由 RD（里约热内卢）引起的结核病病例似乎更有可能是由于近期传播引起的，而不是由非 RD（里约热内卢）菌株引起的，但差异很小。这些观察结果表明，除了 RD（里约热内卢）谱系的固有生物学特征外，其他因素在确定近期传播方面更为重要，并且需要强调采取公共卫生措施来中断新的传播，以控制维多利亚的结核病。
