福建农林大学学报（自然科学版）2025，Vol.54Issue(3)：344-354,11.DOI:10.13323/j.cnki.j.fafu(nat.sci.).202411016
水霉菌的分离、鉴定及人工感染后加州鲈生化指标与组织病理学特征的变化
Changes in biochemical indices and histopathological characteristics of Micropterus salmoides after artificially infection with isolated Saprolegnia
摘要
Abstract
[Objective]This study focused on the effect of Saprolegnia on the biochemical indices of serum,kidney and head-kidney of Micropterus salmoides and its related pathological mechanisms to provide a reference for in-depth exploration of the immune de-fense mechanism of M.salmoides against Saprolegnia.[Method]M.salmoides infected with Saprolegnia were collected from a farm with higher-place ponds in Xifeng County,Guizhou Province.Bacterial strains of Saprolegnia were isolated through surface isolation and cultivation,and then identified by morphological observation,18S rDNA sequencing and bioinformatics techniques.Artificial in-fection with identified Saprolegnia was carried out on healthy M.salmoides to compared their clinical symptoms and skin conditions with the control.Meanwhile,various biochemical indices of serum,kidney and head-kidney were measured,and pathological obser-vations were conducted on tissues including the skin,muscle,gill,liver,head-kidney,kidney,heart and spleen tissues.[Result]The hyphae of Saprolegnia were long and slender,with few branches,and hollow and unseparated tubes;they grew in a spreading manner and distributed scatteredly.After artificial infection with Saprolegnia,M.salmoides exhibited symptoms like reduced activity and decreased appetite,with body surface marked with red patches and white and pale-yellow coverings;fish scales were degenera-ted,disorderly arranged,and even fallen,with most ctenoid spines disappeared at the scale edges;then the epidermis was peeled,leaving the collagen fibers in the dermis layer exposed over a large area.In terms of biochemical indices,the diseased fish had sig-nificantly higher mass fraction of uric acid and alanine aminotransferase(ALT)activity compared to the control,significantly lower mass concentrations of total protein and albumin,alkaline phosphatase(ALP)activity,and concentrations of triglyceride,calcium ion(Ca2+)and chloride ion(Cl-);and very significantly lower mass concentrations of creatinine and sodium ion(Na+).The activ-ities of aspartate aminotransferase(AST)and lactic dehydrogenase(LDH)in the serum were extremely significantly higher in the diseased fish than the control,but exhibited the opposite trends in the head-kidney tissue.In the kidney of diseased fish,ALP activ-ity,mass concentrations of glucose and phosphorus(P+)were all significantly lower than those in the control.Histopathological ob-servation revealed the disordered tissue structures of multiple organs with symptoms such as blood vessel congestion,cell infiltration,swelling,necrosis,and accompanied inflammation in fish infected with Saprolegnia.[Conclusion]The pathogen of diseased M.sal-moides is Saprolegnia,which can cause surface injury,biochemical index changes in serum,kidney and head-kidney,and patholog-ical damages to multiple tissues of M.salmoides.关键词
加州鲈/水霉菌/人工感染/生化指标/组织病理Key words
Micropterus salmoides/Saprolegnia/artificially infection/biochemical indices/histopathology分类
农业科技引用本文复制引用
李志惠,裴占阳,李任军,张小洪..水霉菌的分离、鉴定及人工感染后加州鲈生化指标与组织病理学特征的变化[J].福建农林大学学报（自然科学版）,2025,54(3):344-354,11.基金项目
贵州省科技计划项目(黔科合支撑[2023]一般470). （黔科合支撑[2023]一般470）
