Phospholipase D-neutralization in serodiagnosis of Arcanobacterium haemolyticum and Corynebacterium pseudotuberculosis infections

Phospholipase D (PLD) neutralization was used to examine sera of humans (n = 40) with a spontaneous infection by Arcanobacterium haemolyticum, sheep a nd goats (n = 76 and 79 respectively) with a spontaneous infection by Coryn ebacterium pseudotuberculosis , mice (n = 26) experimentally immunized with PLD from A. haemolyticum (PLD-A) and mice (n = 28) experimentally immunize d with PLD from C. pseudotuberculosis (PLD-C). PLD-A and PLD-C were also us ed as neutralizing antigens. A positive result of neutralization was due to an inhibition of the haemolytic synergism with the equi factor from Rhodoc occus equi. The titres of sera neutralizing the homologous PLD were always significantly higher than those neutralizing the heterologous PLD. The prop ortion of sera that were able to neutralize the homologous PLD in sheep, go ats and mice immunized with PLD-A significantly exceeded the proportion of sera that neutralized the heterologous PLD. The antigenic properties of PLD -A and PLD-C were similar but not identical.