The protective immune response of yellowtail Seriola quinqueradiata to the bacterial fish pathogen Lactococcus garvieae.
Yellowtail Seriola quinqueradiata were immunized with 2 different Lactococcus garvieae bacterin, formalin-killed KG- phenotype cells (capsulated phenotype) and formalin-killed KG+ phenotype cells (unencapsulated phenotype). These 2 injected vaccines conferred long-term protection to yellowtail against an artificial infection of an encapsulated Lactococcus garvieae strain with long-lasting agglutinating titres against KG+ phenotype cells. However, no agglutinating titres or low agglutinating titres against KG- phenotype cells were detected in fish given each of these bacterin. These results suggested that a capsule in KG- phenotype cells apparently affects their immunogenicity, but the antigens which conferred protection to fish against lactococcal infection may be located on the surface of KG+ phenotype cells, and are not cell capsules in KG- phenotype cells. The protection offered by a formalin-killed KG+ phenotype cell vaccine would not appear to be strain specific. Encapsulated L. garvieae cells were well phagocytosed, and fimbrie-like appendages were seen in KG- phenotype cells after treatment with yellowtail immune serum.
Ooyama
T
T
Miyazaki Fisheries Station, Japan.
Kera
A
A
Okada
T
T
Inglis
V
V
Yoshida
T
T
D000372:Agglutination Tests / Q000662:veterinary; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D016667:Bacterial Capsules / Q000276:immunology; D001428:Bacterial Vaccines; D005393:Fish Diseases / Q000276:immunology* / Q000382:microbiology / Q000517:prevention & control; D005399:Fishes; D016908:Gram-Positive Bacterial Infections / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary*; D007116:Immunization, Passive; D017045:Lactococcus / Q000145:classification / Q000276:immunology*; D010587:Phagocytosis; D010641:Phenotype
D000907:Antibodies, Bacterial; D001428:Bacterial Vaccines