[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. pertussis bacteria in lower monkeys as the most adequate model for extrapolation ofthe experiment results to humans. By means of the real-time PCR method, it was established that the B. pertussis bacteria lived more than three months in the upper respiratory tract after a single intranasal monkey infection; the period was reduced to 14-28 days during repeated infection. An increase in the portion of B. pertussis Bvg mutants in the population to tens of percent from the total number of registered bacteria was registered. The experimental confirmation ofthe development and accumulation of avirulent B. pertussis Bvg mutants during the development of the infectious process was obtained. Further study of the composition of the B. pertussis persistent bacteria population at different stages of the disease will make it possible to formulate new approaches to the whooping cough diagnostics and prevention and creation of fundamentally new drugs.

[Experimental whooping cough of nonhuman primate].

Despite considerable success in study of Bordetella pertussis virulence factors, pathogenesis of whooping cough, duration of B. pertussis bacteria persistence, types and mechanisms of immune response are still keep underinvestigated. It can be explained by the absence ofadequate experimental animal model for pertussis study. Our study estimates clinical and laboratory parameters of whooping cough in non-human primates of the Old World in the process of intranasan infection by virulent B. pertussis bacteria. Also the duration of B. pertussis bacteria persistence in animals was investigated. 14 animal units of 4 species of non-human primates of the Old World were used for intranasal infection. The examination of infect animals included: visual exploration of nasopharynx, thermometry, clinical and biochemical blood analyses, identification ofB. pertussis, using microbiologic and molecular genetic analyses, estimation of innate and adoptive immune factors. The development of infectious process was accompanied by generation of B. pertussis bacteria, catarrhal inflammation of nasopharyngeal mucosa, leucocytosis, hypoglycemia specific for pertussis, and activation of innate and adaptive immunity for all primates regardless of specie were seen. While repeated experimental infection in primates single bacterial colonies were registered during only first week after challenge. It occurs like the absence of inflammation of nasopharyngeal mucosa and the lack of laboratory marks of whooping cough, recorded after first challenge. The evident booster effect of humoral immunity was observed. As a model for investigation of B. pertussis bacteria persistence and immune response against whooping cough we suggest the usage of rhesus macaque as more available to experiments.