Authors
1
Department of Aquatic Health and Diseases, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.
2
Iranian Fisheries Sciences Research Institute, Agricultural Research Education and Extension Organization (AREEO), Tehran, Iran.
3
Department of Biology, Roudehen Branch, Islamic Azad University, Roudehen, Iran.
4
Department of Food Hygiene, Science and Research Branch, Islamic Azad University, Tehran, Iran.
5
Department of Marine Science and Technology, Islamic Azad University, North Tehran Branch, Tehran, Iran
10.22092/ijfs.2023.128662
Abstract
The present research was conducted on 600 zebrafish in four parallel groups, including two control and two experimental groups. The experimental groups (T1, T2) were fed commercial fish feed, along with probiotic Lacticaseibacillus casei, while the other two groups (T3, C) only received commercial feed. At the end of four weeks of the feeding, Fish in the groups T2 and T3 were divided and exposed to Aeromonas hydrophila at two concentrations included 1.5×108 (T2 and T3) and1.5×104 (N2 and N3). In this study, the colonization of Lactobacillus in the gastrointestinal tract in the first and last days of the feeding, weight and length in days 0, 15 and 30, and intestinal histology and expression of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) genes using real-time PCR method on days 0, 15, 30 and 35 were done. Based on the results of the present study, feeding with L. casei led to the improved the expression of immune-related genes, enhancement epithelial integrity and goblet cells in the intestine, and weight and length of zebrafish (p<0.05). While it had no significant effect on the rate of colonization of Lactobacillus in the gastrointestinal tract (p>0.05). This results revealed that probiotic feeding led to the reduction of the mRNA levels of IL-1β and TNF-α genes before exposure to the A. hydrophila (p<0.05). while, after exposure, there was a significant increase in the expression level of genes. This elevation was significantly higher in T3 and N3 than in T2 and N2 (p<0.05). As the results indicated, dietary supplementation of L. casei can be effective in enhancement of growth and protection of zebrafish against A. hydrophila by improving their mucosal immunity and modulating inflammatory responses. Since zebrafish is an animal model with genetic compatibility with humans and A. hydrophila pathogenicity in humans, the results obtained can be generalized to humans.
Keywords
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