R. Nielsen et al., Evaluation of an indirect enzyme-linked immunosorbent assay (ELISA) for detection of antibodies to the Apx toxins of Actinobacillus pleuropneumoniae, VET MICROB, 71(1-2), 2000, pp. 81-87
The reference strains of the 12 serotypes of Actinobacillus pleuropneumonia
e express one or two of three different RTX exotoxins designated Apr I, Apr
II and Apr III. The toxins are important virulence factors. In the present
study, ELISAs with purified Apr I, Apr II and Apr III, respectively, as an
tigen were evaluated as candidates for serological diagnosis of Actinobacil
lus pleuropneumoniae infection in pigs, The pigs were inoculated with bioty
pe 1, serotypes 1-12, and biotype 2, serotype 14, respectively. A strong hu
moral antibody response was seen to all the three antigens in most pigs irr
espective of the serotype used for inoculation. However, titers to the exot
oxins secreted by the serotype used for inoculation were generally highest.
The results show that toxin proteins of Actinobacillus pleuropneumoniae li
ne are antigenically related and that a correlation between serotype and se
cretion of exotoxin is not revealed serologically in the ELISA test. (C) 20
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