[Engineering of attenuated Bordetella pertussis bacteria producing immunogenic non-toxic form of pertussis toxin].

AIM: To engineer attenuated Bordetella pertussis strain producing non-toxic immunogenic derivative of pertussis toxin (toxoid KT). MATERIALS AND METHODS: Cloning, site-directed mutagenesis, allelic exchange as well as methods for determination of immunobiological characteristics of toxoid KTwere used. RESULTS: Attenuated B. pertussis strains 5 and 35 containing mutant operon ptx and gene of resistance to canamycin were engineered. Recombinant bacteria retained marker of resistance to canamycin as well as structure of mutant operon during cultivation on growth media and long-term survival in lung of laboratory mice. Immunobiologic characteristics of attenuated B. pertussis were studied. CONCLUSION: Intranasal immunization of laboratory animals with live attenuated B. pertussis 5 and 35 provides protection from infection with virulent B. pertussis strain, which is comparable with efficacy of standard whole-cell vaccine.