Journal of Bacteriology & Parasitology

A new paradigm for genus Mycobacterium population structure

International Congress on Bacteriology & Infectious Diseases

November 20-22, 2013 DoubleTree by Hilton Baltimore-BWI Airport, MD, USA

Paul Jeffrey Freidlin

Scientific Tracks Abstracts: J Bacteriol Parasitol

Abstract:

Background: The genus Mycobacterium contains 150 currently recognized rapidly (RGM) or slowly (SGM) growing species. The SGM Mycobacterium tuberculosis is a major cause of human infection and mortality. Non-tuberculosis mycobacteria (NTM) are increasingly recognized as wide-spread opportunistic human pathogens. Demands for quicker and more accurate identification of species spur usage of genomic polymorphism to facilitate identification of Mycobacterium species. However, obtaining from this molecular data a robust phylogeny or population structure for the genus Mycobacterium remains elusive. Results: rpoB 342 bp gene fragment sequences for 47 Mycobacterium species and 3 related species Corynebacterium diphtheria, Nocardia nova, and Rhodococcus equi, were obtained from GenBank. In silico restriction using Javascript with Perl regular expressions was performed for 5 restriction enzymes. 30 restriction sites were identified and used to generate a minimum spanning tree (MST) which was highly polarized and could be empirically divided into 3 regions. Certain restriction site alleles were in linkage disequilibrium with the MST regions. MST-region 1 contained all the RGM and a halo of SGM which for certain alleles were similar to RGM, and significantly different from MST-region 3 SGM. Mycobacterium genotypes, such as number of rrn rRNA operons and promoters, were consistent with the model. Rhodococcus equi was associated with MST-region 1 RGM as expected from genomic studies. Conclusion: The MST-regions model of genus Mycobacterium population structure was robust, unambiguous, transparent for alleles, consistent with genotypes and phenotypes, and statistically testable. Genomic comparisons based on the model should provide information that will yield new therapeutics and vaccines.

Biography :

Paul Jeffrey Freidlin completed his B.Sc. with honors from University of Maryland, and Ph.D. Department of Microbiology and Public Health, Michigan State University in 1979, East Lansing. Postdoctoral: Tel-Aviv University. Research and advanced studies in molecular and population genetics, DNA markers: 1998 Hebrew University of Jerusalem, Faculty of Agriculture, Rehovot, rank of lecturer. Bioinformatics and Net Programming: Weizmann Institute of Science. 2001 Israel National Mycobacterium Reference Laboratory, Tel Aviv: currently coordinator for molecular biology. Area specialization: molecular epidemiology of tuberculosis. General research interest: understanding biodiversity at the molecular level.