Stanley Browne Laboratory, TLM Community Hospital, Nand Nagari, Delhi 110093, India.
Infect Genet Evol. 2012 Jan;12(1):121-6. doi: 10.1016/j.meegid.2011.10.023. Epub 2011 Nov 11.
Leprosy is a disease caused by Mycobacterium leprae. Various modes of transmission have been suggested for this disease. Transmission and risk of the infection is perhaps related to presence of the infectious cases and is controlled by environmental factors. Evidence suggests that humidity may favor survival of M. leprae in the environment. Several reports show that non-human sources like 'naturally' infected armadillos or monkeys could act as reservoir for M. leprae. Inanimate objects or fomites like articles used by infectious patients may theoretically spread infection. However, it is only through detailed knowledge of the biodiversity and ecology that the importance of this mode of transmission can be fully assessed. Our study focuses here to decipher the role of environment in the transmission of the disease. Two hundred and seven soil samples were collected from a village in endemic area where active cases also resided at the time of sample collection. Slit skin smears were collected from 13 multibacillary (MB) leprosy patients and 12 household contacts of the patients suspected to be hidden cases. DNA and RNA of M. leprae were extracted and amplified using M. leprae specific primers. Seventy-one soil samples showed presence of M. leprae DNA whereas 16S rRNA could be detected in twenty-eight of these samples. Samples, both from the environment and the patients, exhibited the same genotype when tested by single nucleotide polymorphism (SNP) typing. Genotype of M. leprae found in the soil and the patients residing in the same area could help in understanding the transmission link in leprosy.
麻风病是由麻风分枝杆菌引起的疾病。对于这种疾病，已经提出了多种传播方式。传播和感染的风险可能与传染性病例的存在有关，并受到环境因素的控制。有证据表明，湿度可能有利于麻风分枝杆菌在环境中的存活。有几项报告表明，“自然”感染的犰狳或猴子等非人类来源可能是麻风分枝杆菌的储存库。无生命的物体或媒介物，如传染性患者使用的物品，理论上可能传播感染。然而，只有通过对生物多样性和生态学的详细了解，才能充分评估这种传播方式的重要性。我们的研究重点是在这里破译环境在疾病传播中的作用。从一个流行地区的一个村庄收集了 207 个土壤样本，当时在样本采集时，该村庄也有活动病例。从 13 名多菌型（MB）麻风病患者和 12 名患者的家庭接触者中采集了皮肤切片。使用麻风分枝杆菌特异性引物提取和扩增 M. leprae 的 DNA 和 RNA。71 个土壤样本显示存在麻风分枝杆菌 DNA，而在其中 28 个样本中可以检测到 16S rRNA。通过单核苷酸多态性 (SNP) 分型检测，无论是来自环境还是来自患者的样本，均显示出相同的基因型。在同一地区居住的土壤和患者中发现的麻风分枝杆菌的基因型有助于理解麻风病的传播途径。
