title: Variations of immune parameters in the lined seahorse Hippocampus erectus after infection with enteritis pathogen of Vibrio parahaemolyticus.
abstract: Enteritis has been increasingly recognized as one of the major obstacles for the lined seahorse Hippocampus erectus mass culture success. In the present study, the intestinal bacteria strains of the lined seahorses H. erectus suffered from enteritis were isolated, then their pathogenicities were confirmed by artificial infection, and one pathogenic bacteria strain named DS3 was obtained. The median lethal dose (LD50) of strain DS3 for 10 days was determined. The seahorses with different infection levels of uninfected (control), early stage of infection (ESI) and late stage of infection (LSI) were respectively sampled at 0, 3, 6 and 9 days post infection, and 12 immune parameters in the plasma were analyzed. The strain DS3 identified with a biochemical test combined with a molecular method was Vibrio parahaemolyticus, and its LD50 for 10 days was 1.3 × 10(3) cfu/fish. Six parameters including monocytes/leucocytes, leucocytes phagocytic rate, interleukin-2, interferon-α, lysozyme and immunoglobulin M exhibited a generally similar variation trend: highest in the control, second in the ESI and lowest in the LSI throughout the entire experiment. In view of the infection level of V. parahaemolyticus to H. erectus is largely decided by the seahorse's own immune capacity, therefore, these immune parameters were high in the non- or slightly infected seahorses, and low in the severely infected individuals may be an indicator for immune level. These immune parameters may be reliable indicators for the juvenile and broodstock quality assessment. Moreover, clarification of the enteritis pathogen also provides guidances for targeted medicine choice for the lined seahorse.
authors: East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of East China Sea & Oceanic Fishery Resources Exploitation and Utilization, Ministry of Agriculture, Shanghai 200090, PR China.
authors: Tingting
authors: T
authors: Lin
authors: East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of East China Sea & Oceanic Fishery Resources Exploitation and Utilization, Ministry of Agriculture, Shanghai 200090, PR China. Electronic address: zhangdong@eastfishery.ac.cn.
authors: Dong
authors: D
authors: Zhang
authors: East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of East China Sea & Oceanic Fishery Resources Exploitation and Utilization, Ministry of Agriculture, Shanghai 200090, PR China.
authors: Xin
authors: X
authors: Liu
authors: East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of East China Sea & Oceanic Fishery Resources Exploitation and Utilization, Ministry of Agriculture, Shanghai 200090, PR China.
authors: Dongxue
authors: D
authors: Xiao
mesh_terms: D000818:Animals; D004269:DNA, Bacterial / Q000235:genetics / Q000378:metabolism; D004751:Enteritis / Q000235:genetics / Q000276:immunology / Q000382:microbiology / Q000662:veterinary*; D005393:Fish Diseases / Q000235:genetics / Q000276:immunology* / Q000382:microbiology; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA / Q000662:veterinary; D023701:Smegmamorpha; D014735:Vibrio Infections / Q000235:genetics / Q000276:immunology / Q000382:microbiology / Q000662:veterinary*; D014736:Vibrio parahaemolyticus / Q000502:physiology
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S
keywords: Enteritis; Immune indicator; Infection level; Lined seahorse Hippocampus erectus; Vibrio parahaemolyticus