Lavania Mallika, Jadhav Rupendra, Turankar Ravindra P, Singh Itu, Nigam Astha, Sengupta U
Stanley Browne Research Laboratory, The Leprosy Mission Community Hospital, NandNagri, Shahdara, New Delhi 110093, India.
Stanley Browne Research Laboratory, The Leprosy Mission Community Hospital, NandNagri, Shahdara, New Delhi 110093, India.
Infect Genet Evol. 2015 Dec;36:256-261. doi: 10.1016/j.meegid.2015.10.001. Epub 2015 Oct 8.
Leprosy is still a major health problem in India which has the highest number of cases. Multiple locus variable number of tandem repeat analysis (MLVA) and single nucleotide polymorphism (SNP) have been proposed as tools of strain typing for tracking the transmission of leprosy. However, empirical data for a defined population from scale and duration were lacking for studying the transmission chain of leprosy. Seventy slit skin scrapings were collected from Purulia (West Bengal), Miraj (Maharashtra), Shahdara (Delhi), and Naini (UP) hospitals of The Leprosy Mission (TLM). SNP subtyping and MLVA on 10 VNTR loci were applied for the strain typing of Mycobacterium leprae. Along with the strain typing conventional epidemiological investigation was also performed to trace the transmission chain. In addition, phylogenetic analysis was done on variable number of tandem repeat (VNTR) data sets using sequence type analysis and recombinational tests (START) software. START software performs analyses to aid in the investigation of bacterial population structure using multilocus sequence data. These analyses include data summary, lineage assignment, and tests for recombination and selection. Diversity was observed in the cross-sectional survey of isolates obtained from 70 patients. Similarity in fingerprinting profiles observed in specimens of cases from the same family or neighborhood locations indicated a possible common source of infection. The data suggest that these VNTRs including subtyping of SNPs can be used to study the sources and transmission chain in leprosy, which could be very important in monitoring of the disease dynamics in high endemic foci. The present study strongly indicates that multi-case families might constitute epidemic foci and the main source of M. leprae in villages, causing the predominant strain or cluster infection leading to the spread of leprosy in the community.
麻风病在病例数最多的印度仍是一个主要的健康问题。多位点可变串联重复序列分析（MLVA）和单核苷酸多态性（SNP）已被提议作为追踪麻风病传播的菌株分型工具。然而，缺乏来自规模和持续时间确定人群的经验数据来研究麻风病的传播链。从麻风病传教团（TLM）位于普鲁利亚（西孟加拉邦）、米拉杰（马哈拉施特拉邦）、沙德拉（德里）和奈尼（北方邦）的医院收集了70份皮肤刮片。应用SNP分型和10个VNTR位点的MLVA对麻风分枝杆菌进行菌株分型。除了菌株分型，还进行了传统的流行病学调查以追踪传播链。此外，使用序列类型分析和重组测试（START）软件对可变数量的串联重复（VNTR）数据集进行了系统发育分析。START软件进行分析以帮助使用多位点序列数据研究细菌种群结构。这些分析包括数据总结、谱系分配以及重组和选择测试。在对70名患者分离株的横断面调查中观察到了多样性。在来自同一家族或邻里地点的病例标本中观察到的指纹图谱相似性表明可能存在共同的感染源。数据表明，这些VNTR包括SNP分型可用于研究麻风病的感染源和传播链，这在监测高流行病灶的疾病动态方面可能非常重要。本研究强烈表明，多病例家庭可能构成流行病灶以及村庄中麻风分枝杆菌的主要来源，导致优势菌株或聚集性感染，从而在社区中传播麻风病。
