DNA fingerprinting analyses of M tuberculosis-complex isolates from the Free State, South Africa, as part of a multidisciplinary study

Abstract

The objective of this study was to serve as a complement to socio-economic analyses of TB patients in a DOTS system, providing microbiological data and documenting the TB population dynamics. Sputum samples were collected from smear-positive TB patients in the Goldfields, Thaba Nchu and Qwaqwa areas. Laboratory analyses comprised the culturing of Mycobacterium tuberculosis isolates and DNA fingerprinting. The primary aim was hampered by problems encountered during specimen sampling, inadequate resources, and a low culture-positivity rate. Nevertheless, the fingerprinting data of a random sample showed a heterogenous TB population, suggesting that reactivation might be an important factor in the area studied. Clustering was the highest in the mining area. Preliminary data from serial isolates also detected possible re-infection during treatment or initial mixed infections in five of the eleven patients.