CONSTRUCTION OF SALMONELLA STN-DEFICENT MUTANTS AND DETECTION OF THEIR VIRULENCE / 解放军医学杂志

ABSTRACT

The plasmids of recombinant suicide vector containing the truncated stn gene and the deleted stn gene were constructed. The Salmonella stn-deficient mutant was prepared by homologous recombination between the mutant stn gene in the recombinant suicide vector and the wild-type gene in the chromosome of S. Typhimurium 2000. The detection of biological activity of stn gene production in those mutants indicated that Salmonella stn-deficient mutants evoked significantly less fluid secretion in mouse intestinal loops compared to that seen with wild-type Salmonella. Upon oral challenge of mice, the fifty percent lethal dose of the Salmonella stn-deficient mutants was greater than that for the wild-type bacteria. Those studies showed that the stn gene is very important factor in the pathogenesis of salmonellosis.