Identification of Actinobacillus pleuropneumoniae strains of serotypes 7 and 4 using monoclonal antibodies: demonstration of common LPS O-chain epitopes with Actinobacillus lignieresii.
Monoclonal antibodies (Mabs) against Actinobacillus pleuropneumoniae serotype 7 were produced and characterized. Three Mabs directed against surface polysaccharides were selected. One of the Mabs was directed against a capsular polysaccharide epitope (CPS) of A. pleuropneumoniae serotype 7 whereas two other Mabs reacted with different epitopes of the LPS O-chain. One of the latter reacted with the reference strain of serotype 7 and the other one with serotypes 7 and 4. These three Mabs were used to test, by Dot-ELISA, 508 field strains of A. pleuropneumoniae. None of the strains belonging to other serotypes different from serotypes 4 and 7 were positive with the Mabs. Used in combination, the CPS and one of the LPS O-chain directed Mabs were shown to be suitable for serotyping since they detected 100% of serotype 7 strains. In this study, we confirm for the first time that A. pleuropneumoniae serotype 4 is present in North America. Finally, both O-chain specific Mabs also reacted with the O-chain of Actinobacillus lignieresii. The cross-reactivity between the two species was confirmed using sera from pigs experimentally infected with A. pleuropneumoniae serotype 7 and A. lignieresii, using immunoblotting and ELISA. This is the first report of a specific cross-reactivity between the LPS of these bacterial species.
Lebrun
A
A
Groupe de Recherche sur les Maladies Infectieuses du Porc, Faculté de médecine vétérinaire, Université de Montréal, St. Hyacinthe, Qué, Canada.
Lacouture
S
S
Côté
D
D
Mittal
K R
KR
Gottschalk
M
M
D000188:Actinobacillus / Q000276:immunology*; D016977:Actinobacillus pleuropneumoniae / Q000145:classification* / Q000276:immunology*; D000818:Animals; D000911:Antibodies, Monoclonal; D000918:Antibody Specificity; D003429:Cross Reactions; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000032:analysis; D015151:Immunoblotting; D051379:Mice; D008807:Mice, Inbred BALB C; D019081:O Antigens / Q000276:immunology*; D012703:Serotyping
D000911:Antibodies, Monoclonal; D000939:Epitopes; D019081:O Antigens