title: Effect of dietary β-glucan on growth, survival and regulation of immune processes in rainbow trout (Oncorhynchus mykiss) infected by Aeromonas salmonicida.
abstract: The present study evaluated the effects of dietary β-glucan (0, 0.05%, 0.1%, and 0.2%) on growth performance after 42 days of feeding. Thereafter, rainbow trout (Oncorhynchus mykiss) were infected with Aeromonas salmonicida, and survival rates as well as the regulating processes of stress- and immune-related factors were analyzed. In general, higher dietary β-glucan levels obviously improved specific growth rate (SGR), weight gain (WG) and feed efficiency (FE) (P ≤ 0.05). Survival rates in β-glucan groups increased significantly compared with the control group after A. salmonicida infection (P ≤ 0.05). Serum total superoxide dimutase (T-SOD), peroxidase (POD) as well as catalase (CAT) activities, and their mRNA expressions in the head kidney of fish in the β-glucan groups generally increased to higher levels after infection, and more quickly, compared with in the control group. Serum lysozyme (LSZ) and its expression in the head kidney in β-glucan groups reached a higher peak earlier than in the control group. Serum glutamic oxalacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) levels in the β-glucan groups were significantly lower than in the control group (P ≤ 0.05). The peak of heat shock protein 70 (HSP70) expression in the 0.2% β-glucan group was higher and occurred earlier than in other groups (P ≤ 0.05). These results confirm that 0.1% and 0.2% dietary β-glucan are beneficial for promoting growth in rainbow trout and enhancing resistance against A. salmonicida. Furthermore, β-glucan could play an important role in regulating stress- and immune-related factors in rainbow trout to more quickly fight against bacterial infection.
authors.affiliation: Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China; University of Chinese Academy of Sciences, Beijing, 100039, China.
authors.forename: Liqin
authors.initials: L
authors.lastname: Ji
authors.affiliation: Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China.
authors.forename: Guoxiang
authors.initials: G
authors.lastname: Sun
authors.affiliation: School of Biological Sciences, Lake Superior State University, Sault Ste. Marie, MI, 49783, United States.
authors.forename: Jun
authors.initials: J
authors.lastname: Li
authors.affiliation: School of Marine Science and Environment Engineering, Dalian Ocean University, Dalian, 116023, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China.
authors.forename: Yishuai
authors.initials: Y
authors.lastname: Du
authors.affiliation: Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China.
authors.forename: Xian
authors.initials: X
authors.lastname: Li
authors.affiliation: School of Marine Science and Environment Engineering, Dalian Ocean University, Dalian, 116023, China. Electronic address: yingliu@dlou.edu.cn.
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage / Q000502:physiology; D048409:Aeromonas salmonicida / Q000502:physiology; D000821:Animal Feed / Q000032:analysis; D000818:Animals; D004032:Diet / Q000662:veterinary; D019587:Dietary Supplements / Q000032:analysis; D060467:Disease Resistance; D004305:Dose-Response Relationship, Drug; D005393:Fish Diseases / Q000276:immunology* / Q000382:microbiology; D029941:Fish Proteins / Q000235:genetics / Q000378:metabolism; D016905:Gram-Negative Bacterial Infections / Q000276:immunology / Q000382:microbiology / Q000662:veterinary*; D060226:Head Kidney / Q000276:immunology / Q000378:metabolism; D007113:Immunity, Innate; D017686:Oncorhynchus mykiss / Q000254:growth & development / Q000276:immunology; D011897:Random Allocation; D047071:beta-Glucans / Q000008:administration & dosage / Q000276:immunology*
chemical_list: D000276:Adjuvants, Immunologic; D029941:Fish Proteins; D047071:beta-Glucans
keywords: Aeromonas salmonicida; Growth; Immune-related factors; Oncorhynchus mykiss; Survival; β-glucan