An Analysis upon Molecular Epidemiology of Mycobacterium Tuberculosis to Control TB: A Case Report: Investigating the Fitness and Transmission Patterns of Drug-Resistant Mycobacterium Tuberculosis

Abstract

It is estimated that one third of the world‘s population are infected with the bacterium M. tuberculosis and approximately 9.4 million new cases of tuberculosis were diagnosed globally in 2008. Molecular tools, developed over the previous two decades, have allowed further in-depth study of this historic disease. Genotyping M. tuberculosis allows the study of evolutionary relationships and well as the routes of transmission of the organism between hosts. The pairing of genotyping with demographic data allows the analysis of the current trends of disease within a given patient population.The acquisition of drug resistance-conferring mutations by M. tuberculosis is often presumed to be associated with a fitness cost. Here we investigate the fitness of isolates from two outbreaks involving large numbers of drug resistant strains. The first group of strains was found to be part of the ongoing north London isoniazid resistant outbreak. The data suggests that this outbreak consists of successful, closely related, circulating strains with heterogeneous resistance profiles and mutations and little or no associated fitness cost.