Authors
1
Department of Clinical Sciences, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran
2
Graduated Student from the Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran
3
Department of Pathobiology, Faculty of Veterinary Medicine, Shahid Chamran University, Ahvaz, Iran
4
Department of Food Hygiene, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran
Abstract
BACKGROUND: Occurrence of resistance against antibiotics
and inadequate efficacy of some vaccines necessitates studies of
natural immunostimulators in aquaculture. Shrimps shell derived
from Chitosan can be used as immune stimulators in fish.
OBJECTIVES: In this study, the effects of oral administration of
chitosan, derived from shrimp shell, on some immune responses
and disease resistance in Cyprinus carpio were studied. METHODS:
Three hundred healthy fish weighing 42.4+8.1 g were divided into
4 equal groups: the first group (G10) was fed with food
supplemented with 10 mg kg-1 chitosan, the second (G5) and third
groups (G2.5) were fed with food supplemented with 5 mg kg-1 and
2.5 mg kg-1, respectively. The control group was fed with basal feed
(without chitosan). All groups were treated for 60 days. Blood
samples were taken on 0, 20, 40, and 60 days post- experiment; In
addition, some immunological indices, including serum lysozyme
activity, serum bactericidal activity, Nitro Blue Tetrazolium (NBT)
reduction activity, serum proteins, white blood cell count (WBC),
and differentiated count were measured. At the end of the treatment,
fish were challenged with live Aeromonas hydrophila and mortality
rate was recorded for 14 days. RESULTS: Oral administration of
chitosan (0.5 and 1%) significantly enhanced NBT reduction
activity and resistance to A. hydrophila infection (p=0.012). Serum
lysozyme and bactericidal activity, serum total protein and
globulin, WBC and leukocytes ratio showed no significant change
among the groups (p>0.05). CONCLUSIONS: This study indicates
that oral administration of shrimp shell chitosan may have a positive
effect on some immune parameters and resistance against bacterial
infection in Cyprinus carpio.
Keywords
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