Streptococcus iniae, a bacterial infection in barramundi Lates calcarifer

Citation
Es. Bromage et al., Streptococcus iniae, a bacterial infection in barramundi Lates calcarifer, DIS AQU ORG, 36(3), 1999, pp. 177-181
Citations number
28
Categorie Soggetti
Aquatic Sciences
Journal title
DISEASES OF AQUATIC ORGANISMS
ISSN journal
01775103 → ACNP
Volume
36
Issue
3
Year of publication
1999
Pages
177 - 181
Database
ISI
SICI code
0177-5103(19990531)36:3<177:SIABII>2.0.ZU;2-J
Abstract
The cause of ongoing mortality in barramundi Lates calcarifer (Bloch) in se awater culture was identified as Streptococcus iniae by biochemical and phy siological tests. This is the first published record of this bacterial spec ies in Australia and the first confirmed report of S. iniae causing mortali ty in barramundi. The bacterium was highly pathogenic for barramundi when c hallenged by bath exposure. The pathogen was found to have a LD50 Of 2.5 x 10(5) and 3.2 x 10(4) colony-forming units at 48 h and 10 d respectively. E xperimental challenge of barramundi resulted in high levels of mortality (> 40%) within a 48 h period. Ten days after the challenge, S, iniae could not be isolated from kidney, spleen, liver or eye of surviving fish. However, the organism was easily isolated from the brain of both moribund and health y fish, indicating that barramundi can carry the bacterium asymptomatically .