Gamaleya Research Institute of Epidemiology and Microbiology, Moscow; Bashkir State Medical University, Ufa, Russia
Five types of nonhomologous systems of the export of protein molecules, known to exist in pathogenic bacteria, are characterized. The described secretion systems take part in the synthesis of not only toxic proteins, but also different adhesins and hydrolytic enzymes. In the export of Enterobacteriaceae toxins secretion types I, II, III and V are of importance. Characteristics of Sec-dependence at the stage of transport through the cytoplasmic membrane is the key sign in their differentiation. The functional activity of bacterial toxins and the level of toxigenicity expression are finely regulated signs, mediated by external signals. The systems for their regulation are relatively few in number and rather conservative. As shown in this study, the regulation of pathogenicity expression has no specific mechanisms. Moreover, it is regulated by common systems and mechanisms for the regulation of usual physiological processes.
Zh. Mikrobiol. (Moscow), 2002, No. 5, P. 86—91