CBTBR contributes to international spoligotype database

SEPTEMBER 2005

Spoligotyping is a molecular fingerprinting method used to genotypically characterize different Mycobacterium tuberculosis strains. The method is based on a polymorphic locus in the genome of M. tuberculosis. The fingerprints generated for each isolate can assist in answering various epidemiological questions. An international database exists with more than 13000 isolates from more than 90 countries. Although this is very useful for comparisons, a major drawback is that there are very few entries from countries in Africa at present in the database and this is the continent that is the most affected by tuberculosis. We have established a database with genotypic and phenotypic data of M. tuberculosis isolates from patients from suburbs in Cape Town, rural parts in Western Cape Province, other settings in South Africa and also selections of isolates from different countries in Africa.  The spoligotypes of about 3000 isolates have recently been submitted to the international spoligotype database and will contribute to our knowledge of strains circulating in Africa in comparison to the rest of the world.

CBTBR investigates the respiratory chain of Mycobacterium...

SEPTEMBER 2005

An important property of bacterial pathogens is the ability to adapt to complex and changing environments during the course of an infection. One particularly active area of interest in the TB field is to understand how mycobacteria are able to adapt to conditions of varying availability of oxygen. In a paper published in the September 2005 issue of the Journal of Bacteriology, researchers from the Wits node of the CBTBR used a combination of targeted gene knockout and global gene expression analysis by DNA microarray to examine how the aerobic respiratory chain of Mycobacterium smegmatis adapts to blockage of the preferred pathway via which electrons flow to oxygen. This work formed the basis of the PhD project of Ms Limenako Matsoso (who will graduate in early 2006), and was carried out in collaboration with researchers at Monash University in Australia, and the University of Pennsylvania in the USA.