Virulence for Mice of pH6⁺ and pH6^– <i>Yersinia pestis</i> Strains

Abstract

The technique of site-directed mutagenesis of psa operon encoding the synthesis of pH6 antigen (adhesion pili), followed by the trans-complementation procedure were used to construct two sets of isogenic Yersinia pestis strains including wild type strains 231 and I-1996, their non-polar pH6- mutants containing deletions in the structural psA gene or in the entire operon, as well as the strains which could recover their capability for temperature- and pH-dependent synthesis of the adhesion pili or the constitutive pH6 antigen production. The loss of the ability to synthesize the pH6 antigen and its constitutive production was shown to affect neither their virulence characteristics nor mean lifetime assessments for the subcutaneously infected mice.

Keywords

• virulence
• <i>yersinia pestis</i>
• ph 6 antigen