Antibacterial
abilities of intestinal bacteria from larval and juvenile Japanese flounder
against fish pathogens
H. Sugita, R. Okano, Y. Suzuki, D. Iwai,
M. Mizukami, N. Akiyama, S. Matsuura-2002
Fisheries Science, 68(5):
1004-1011
Abstract:
The present study was undertaken to
examine the antibacterial abilities of intestinal bacteria isolated from
juveniles and larvae of Japanese flounder Paralichthys olivaceus.
Newly hatched larvae of flounder were held in a 100 L plastic circular
tank and fed rotifiers, Artemia nauplii and commercial feeds,
depending on the developmental stage of the fish. Genera Aeromonas, Moraxella
and Vibrio were predominantly isolated from the intestinal tracts of
Japanese flounder at larval and juvenile stages, whereas Aeromonas, Bacillus,
coryneforms, Moraxella, Pseudomonas and Vibrio were
detected at high densities in live diets and artificial feeds. Antibacterial
bacteria accounted for 1.7-24.3% of the intestinal isolates against Lactococcus
garvieae, Pasteurella piscicida, Vibrio anguillarum and V.
vulnificus. In particular, as much as 53.3% of Vibrio spp. other
than Vibrio-swarmer isolated from 197-day-old juveniles inhibited the
growth of P. piscicida. These results suggest that intestinal
bacteria having antibacterial activity play a role in the prevention of
infectious diseases.
(Department of Marine Science and Resources, Nihon
University, Fujisawa, Kanagawa 252-8510, Japan, Tel: 81-466-84-3679. Fax: 81-466-84-3679. Email: sugita@brs.nihon-u.ac.jp)