Mechnikov Research Institute of Vaccines and Sera; Gabrichevsky Moscow Research Institute of Epidemiology and Microbiology, Moscow, Russia
Aim. To assess level of pertussin toxin (PT) production by vaccine strains of Bordetella pertussis and strains isolated from patients with whooping cough. Materials and methods. Concentration of PT in supernatants of microbial cultures of 3 vaccine strains and 25 strains of B.pertussis isolated from patients with pertussis in 2001 — 2005 was measured with enzyme immunoassay using gamma-globulin fractions of rabbit antiserum to PT as immunosorbent or included in peroxidase conjugates. Results. Level of PT production by strains isolated from infected persons varied from 3±0.5 to 64.8±12.2 ng/MFU/ml: in 9 strains — from 3±0.5 to 9.4±2.1 ng/MFU/ml, in 7 — 10.5±1.8 to 18.4±2.6 ng/MFU/ml, and in 9 — 23.6±4.5 to 64.8±12.2 ng/MFU/ml. Conclusion. B.pertussis strains isolated from patients were heterogeneous on level of PT production. Difference in expression of PT between strains were as high as 20-fold. Conditionally low, moderate and high levels of PT production had 9 (36%), 7 (28%), and 9 (36%) of 25 studied strains. Three vaccine strains had levels of toxin production similar to recently isolated strains with moderate level of its production.
Zh. Mikrobiol. (Moscow), 2011, No. 1, P. 76—79