The use of molecular techniques to study microbial determinants of pathogenicity

Abstract

A variety of new methods in DNA biochemistry, molecular biology and genetics have become available for the analysis of microbial determinants of pathogenicity. It has never been easier to focus upon specific genetic determinants and to manipulate them directly to meet experimental goals. Although the principles of genetic manipulation have been used with considerable success in enteric bacteria, it is not always a straightforward matter with other microorganisms. We were unable to cloneBordetella pertussisdeterminants of pathogenicity directly inEscherichia coliK12 by selecting for their protein products. It was possible, however, to develop a genetic transfer system and methods for the identification of specificBordetellavirulence genes. These studies not only provided the basis for the eventual successful genetic cloning ofBordetella pertussisgenes but also provided an example showing that the molecular cloning of virulence genes is not always an easy task, nor even necessarily the best initial approach to take.