Table 1 Characterization of Ty21a-PA-01 seed bank

From: Protection against inhalation anthrax by immunization with Salmonella enterica serovar Typhi Ty21a stably producing protective antigen of Bacillus anthracis

Assay Method Vial 1 Vial 2 Ty21a Ty2 E. coli
Microbiological API 20 E S. Typhi S. Typhi S. Typhi S. Typhi E. coli
  Colony appearance on Bromothymol blue agar ( + 1% galactose) Blue Blue Blue Yellow Blue
Biochemical Minimal media + cysteine + thiamine + tryptophan No growth No growth No growth Growth No growth
  Minimal media + cysteine + thiamine + tryptophan + valine + isoleucine Growth Growth Growth Growth Growth
  Heat stress at 55 °C for 20 min Sensitive Sensitive Sensitive Resistant Sensitive
  Oxidative stress in 0.3% H2O2 for 20 min Sensitive Sensitive Sensitive Resistant Sensitive
  Galactose (1%) induced bacteriolysis Sensitive Sensitive Sensitive Resistant ND
Immunological 9,12 O-antigen agglutination + + + + ND
  Vi antigen agglutination + ND
  PA Expression (colony and western blot) + + ND ND
Genetic 16 S rDNA sequence Identical to Ty21a Identical to Ty21a Ty21a Ty2 ND
  galE DNA sequence Identical to Ty21a Identical to Ty21a Ty21a (T367C; C442Δ) Ty2 (wild type) ND
  Chromosomally integrated PA expression-secretion cassette (PCR) + + ND
  1. Two random vials from the seed bank were characterized.38 Ty21a (Vivotif), S. enterica serovar Typhi strain Ty2, and E. coli strain HB101 were controls