Modified toxin-binding inhibition (ToBI) test for epsilon antitoxin determination in serum of immunized rabbits.
The aim of the present study was to evaluate and standardize the ToBI test in vitro as a substitute for the serum neutralization test in mice for quality control of clostridial vaccines. The ToBI test in vitro was used to evaluate 40 serum samples of known antibody content, obtained from rabbits immunized against clostridiosis with experimental vaccine. The correlation between epsilon antitoxin titers in rabbit sera, determined by the ToBI test and serum neutralization in mice, ranged from 0.222% to 0.452% in polyvalent vaccines and from 0.154% to 0.387% in monovalent vaccines. Interplate coefficients of variation were not significant, reaching 0.350% in polyvalent vaccines and 0.400% in monovalent vaccines, indicating high homogeneity. In conclusion, the ToBI test in vitro is suitable for assessing the potency of clostridial vaccines and may be used as an alternative method able to replace current in vivo tests.
Sobrinho
Eliane M
EM
Vaccine Technology Laboratory of Vallée S.A., Avenida Hum, 1500, Montes Claros, MG, CEP 39404-003, Brazil.
Cangussu
Alex S R
AS
Brandi
Igor V
IV
Sari
Roger S
RS
Almeida
Anna C
AC
Colen
Fernando
F
Quintilio
Wagner
W
Santos
Hercules O
HO
D000818:Animals; D000992:Antitoxins / Q000097:blood*; D001427:Bacterial Toxins / Q000037:antagonists & inhibitors* / Q000276:immunology; D001428:Bacterial Vaccines / Q000276:immunology / Q000592:standards; D003015:Clostridium Infections / Q000175:diagnosis / Q000276:immunology / Q000517:prevention & control; D003016:Clostridium perfringens / Q000276:immunology*; D004767:Enterotoxemia / Q000175:diagnosis / Q000276:immunology / Q000517:prevention & control; D007114:Immunization; D066298:In Vitro Techniques; D051379:Mice; D009500:Neutralization Tests / Q000379:methods; D011786:Quality Control; D011817:Rabbits; D012698:Serologic Tests / Q000379:methods* / Q000592:standards
D000992:Antitoxins; D001427:Bacterial Toxins; D001428:Bacterial Vaccines; C039811:Clostridium perfringens epsilon-toxin