[Insertional Inactivation of Virulence Operon in Population of Persistent Bordetella pertussis Bacteria].

Avirulent B. pertussis bacteria containing IS elements in the bvgAS operon were detected during the study of whooping cough patients and bacilli carriers. The present work is devoted to the study of the accumulation dynamics and the mechanisms of generation of persistent forms of the B.

[PERSISTENCE OF BORDETELLA PERTUSSIS BACTERIA AND A POSSIBLE MECHANISM OF ITS FORMATION].

A growth of pertussis morbidity is observed in many countries of the world against the background of mass vaccindtion. Forms of the disease course have changed. Atypical forms of pertussis occur predominately in adolescents and adults.

[Construction of the genetically attenuated bacteria Bordetella pertussis devoid of dermonecrotic toxin activity and producing modified nontoxic pertussis toxin form].

The recombinant modified (attenuated) bacteria A. pertussis were constructed. These bacteria contained knockout mutation of the dnt gene and produced nontoxic pertussis toxin derivative.

[A comparative study of the role of the yadA, invA, and psaA genes in the pathogenicity of Yersinia pseudotuberculosis].

The roles of yadA, invA, and psaA genes introduced into the genetic background of the Y. pseudotuberculosis strain possessing the large p VM82 plasmid in virulence and invasion capacity were studied. Isogenic single mutants as well as double and multiple mutants of these genes were constructed and used.

[Bvg-negative regulation of repeated sequence transferring in Bordetella pertussis cells].

A method of monitoring the sequential events of IS481 transposition into the ctag site of bvg operon of Bordetella pertussis has been developed. Reproduction of virulent B. pertussis cells in vitro is accompanied by intrachromosomal site-specific IS481 transposition, which, in turn, results in inactivation of bvg operon of the causative agent and cell avirulent state.