Caseous lymphadenitis vaccine development: site-specific inactivation of the Corynebacterium pseudotuberculosis phospholipase D gene.
Vaccines for ovine caseous lymphadenitis (CLA) are currently formulated using partially purified, formalin inactivated phospholipase D (PLD) derived from Corynebacterium pseudotuberculosis culture supernatants. Chemical treatment has been a common and effective way of inactivating bacterial toxins for use in toxoid vaccines. Genetic inactivation of toxin genes using site-specific mutagenesis has the potential to improve this process by providing a safer and more cost-effective product. In the present study amino acid substitutions at the putative catalytic site and metal binding domain of the PLD protein had a profound affect upon PLD activity and secretion from C. pseudotuberculosis. Two mutated PLD analogues that were secreted to a level of 40% compared to the wild-type and retained minimal activity showed promise for development as recombinant CLA vaccines. Further work will be required to establish their suitability for commercialization.
Tachedjian
M
M
CSIRO Division of Animal Health, Animal Health Research Laboratory, Parkville, Victoria, Australia.
Krywult
J
J
Moore
R J
RJ
Hodgson
A L
AL
D000818:Animals; D001428:Bacterial Vaccines / Q000276:immunology*; D001483:Base Sequence; D003354:Corynebacterium Infections / Q000517:prevention & control / Q000662:veterinary*; D016925:Corynebacterium pseudotuberculosis / Q000235:genetics*; D005557:Formaldehyde; D008199:Lymphadenitis / Q000276:immunology / Q000662:veterinary*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010739:Phospholipase D / Q000235:genetics*; D012756:Sheep
D001428:Bacterial Vaccines; D005557:Formaldehyde; D010739:Phospholipase D