Inhibition of Aeromonas hydrophila‐induced intestinal inflammation and mucosal barrier function damage in crucian carp by oral administration of Lactococcus lactis
- 2018-12
- Fish & Shellfish Immunology 83
- Yuhao Dong
- Yuanyuan Yang
- Jin Liu
- Furqan Awan
- Chengping Lu
- Yongjie Liu
- PubMed: 30236608
- DOI: 10.1016/j.fsi.2018.09.041
Abstract
This study explored the immunomodulatory effect and inhibition effects of the candidate probiotic Lactococcus lactis 16-7, which was isolated from crucian carp, on Aeromonas hydrophila infection in crucian carp. The experimental fish were divided into two groups; one was fed a diet supplemented with L. lactis, while the other was fed the control probiotic-free diet. After feeding for 42 d with the experimental diets, the fish that received the diet supplemented with probiotics exhibited a significantly enhanced serum superoxide dismutase activity, phagocytic activities of innate immune cells, and the expression levels of immune-related genes [interferon-γ (INF-γ), interleukin-1β (IL-1β), interleukin-11 (IL-11), tumour necrosis factor α (TNF-α) and myeloid differentiation factor 88 (MyD88)], indicating that L. lactis 16-7 could activate the non-specific immune system of crucian carp. At the end of the feeding trial, the crucian carps in each group were orally infected with A. hydrophila NJ-35. The results show that L. lactis 16-7 could prevent the increase in d-lactic acid concentration and inflammatory response caused by A. hydrophila in crucian carp. Compared with A. hydrophila group, L. lactis 16-7 preserved the integrity of intestinal villi and mitigated A. hydrophila-induced reduce in the transcriptional levels of tight junction (TJ) proteins zonula occludens-1 (ZO-1) and occludin, indicating that L. lactis 16-7 could reduce intestinal mucosal barrier damage and inflammation induced by A. hydrophila in crucian carp. In addition, L. lactis 16-7 could effectively antagonize the colonization of A. hydrophila in the intestine. Overall, these data clearly indicate that L. lactis 16-7 has the potential to be developed as a probiotic agent against A. hydrophila infection in aquaculture.
Keywords: Aeromonas hydrophila; Crucian carp; Immunomodulatory effect; Intestinal mucosal barrier; Lactococcus lactis.
Research Insights
| Supplement | Health Outcome | Effect Type | Effect Size |
|---|---|---|---|
| Lactococcus lactis VPro 42 | Increased Immune-Related Gene Expression | Beneficial | Large |
| Lactococcus lactis VPro 42 | Increased PMN Cell Phagocytic Capacity | Beneficial | Large |
| Lactococcus lactis VPro 42 | Increased Serum Superoxide Dismutase Activity | Beneficial | Large |
| Lactococcus lactis VPro 42 | Maintained Intestinal Villi Integrity | Beneficial | Large |
| Lactococcus lactis VPro 42 | Reduced Colonization of Aeromonas Hydrophila in the Intestine | Beneficial | Large |
| Lactococcus lactis VPro 42 | Reduced Inflammatory Response | Beneficial | Large |