A Mycobacterium leprae VNTR database.

A great deal of the last quarter of a century’s astonishing progress in understanding and treating human disease is attributable to the existence of public databases where information about DNA sequences, protein sequences, protein structures, human variation, etc. is stored and is freely available to all interested investigators. Information that is developed by one laboratory to help answer a specific question can be combined with, and compared to, similar information from hundreds of other laboratories – information that was developed for hundreds of different, often unrelated, reasons. That process of combining and comparing information is called data mining and is the basis of the successful field of bioinformatics. Once disdained as ‘mere data mining’, it is now well understood that no one laboratory can generate the breadth of information required to gain insight into many key processes related to human diseases. Data that were at one time carefully hoarded by each individual investigator are now freely shared, and all investigators have benefited enormously from that sharing. Indeed, it is now well understood that the application of that information to the practical business of solving human diseases requires that sharing. The recent identification and validation of 16 VNTR (microsatellite) loci in the genome of Mycobacterium leprae has provided a reliable, high-resolution basis for the identification of M. leprae isolates. The method holds the promise of elucidating fundamental information about the epidemiology of M. leprae, including potential sources of infection, the exact mode of transmission, and the potential importance of person-to-person contact. The method is also expected to contribute to our understanding of the basic pathogenesis of the organism, including such matters as the number of organisms required for successful infection, and the time between infection and initial appearance of symptoms of leprosy. A series of eight recent survey studies in six different countries – 10 employed those loci and made clear the value of the VNTR approach and its superiority to earlier approaches to molecular strain typing. Further insight into the global population structure of M. leprae (the division of the global population into clusters of genetically similar strains) and migration of M. leprae between countries, was gained by combining the results of those studies and analysing them as a whole. Combining those results required manually extracting the data from each of the eight papers, a process that was similar to the manual copying of DNA sequences from published papers before