Molecular and pathological identification of Lactococcusgarvieae isolated from cultured rainbow trout in Ilam

Heidarinejad, Saeedeh; Salamat, Negin; Pourhmad, Fazel; Savari, Ahmad; Archangi, Bita

doi:10.22059/jfisheries.2014.50351

Molecular and pathological identification of Lactococcusgarvieae isolated from cultured rainbow trout in Ilam

Document Type : Research Paper

Authors

Saeedeh Heidarinejad ¹

Negin Salamat ²

Fazel Pourhmad ³

Ahmad Savari ⁴

Bita Archangi ⁴

¹ M.Sc. Animal Science-Aquatic Histology of department of Marine Biology, School of Marine Science, Khorramshahr Marine Science and Technology University, Khorramshahr , Iran.

² Assistant professor of department of Marine Biology, School of Marine Science, Khorramshahr Marine Science and Technology University, Khorramshahr , Iran.

³ Assistant professor of School of Veterinary Medicine, Ilam University, Ilam, Iran.

⁴ Assistant professor of department of Marine Biology, School of Marine Science, Khorramshahr Marine Science and Technology University, Khorramshahr , Iran

10.22059/jfisheries.2014.50351

Abstract

In the present study, 60 diseased rainbow trout with clinical signs such as lethargie, erratic swimming and exophthalmia were collected from rainbow trout farms in Ilam in January 2010. For detection the agent of disease, Samples were collected from liver, kidney and spleen of fish and cultured on blood agar and incubated at 22 ^ºC for 24 h. Isolates were confirmed using a m-PCR targeting 16S rRNA, lctO-gene and 16S- 23S rRNA that detect Lactococcus garvieae, Streptococcus iniae and S. dysgalactiae, respectively. In the present study a single band of 1100 bp for L. garvieae for most of isolates. It concluded that the main agent of septicemia was L. garvieae. Edema of the secondary lamellae and epithelial lifting, lamellar capillary aneurysms, hypertrophy and hyperplasia of epithelial cells in gill and thickening of the glomerular basement membrane of glomerulus capsule,tubular cell necrosis, increase of melanomacrophage centers, blood congestion and hemorrhage in the kidney were the most histopathological changes observed in the diseased fish. In conclusion, it seems that Multiplex PCR is a definite method for rapid detection of bacteria in mixed infection.

Keywords

Lactococcus garvieae Streptococcus iniae

pathology

Rainbow trout

multiplex PCR

Subjects