Histopathology,Isolation And Classification And Of One Pathogenic Bacteriaum From Centropristis Striata With Exophthalmic Disease

In recent years,exophthalmic disease has seriously affects on aquaculture industry of C.striata,causing huge economic losses.To explore the cause for exophthalmic disease’ pathogens,serum biochemical index,and the influence of histopathology for C.striata,using by physiological and biochemical,molecular biology technology,the serum biochemical indicators analysis,transmission electron microscopy,paraffin slice.As follows research:1.Pathogen isolation and identification: A strain of bacterial pathogen was isolated from eyeballs of a cultured Centropristis striata fry with the symptom of eyeballs are white chaotic,hyperaemia and paraplasm.The strain grew quickly on the TCBS culture medium,and the colonies were caelate,yellow,and tackiness.The strain is belong to Gram-negative bacterium,bacillus and monotricha,named CJG01.The intramuscular injection experiment revealed that the strain named CJG01 virulent to Centropristis striata with an LD50 value of 2.67×105 colony forming units/ml.The strain CJG01 can cause the larval exophthalmos,fall off,muscle ulceration,and fishbone exposed.Anatomical observation: liver inflammation,splenic organ Enlargement,kidney inflammation and with yellow liquid in intestinal.The results of API 20 NE rapid identification and related physiological and biochemical additional experiments shows that growth temperature for the strain CJG01 is from 28 ℃to 37 ℃.The optimum temperature for is at 28 ℃.The stain CJG01 can grow on TSB culture medium from 0% to 5% salinity.The strain CJG01 is sensitive to vibrio inhibitors O/129,oxidase reaction positiving,ornithine decarboxylase positiving,and V-P negativing.The strain CJG01 can assimilate mannitol,maltose,malic acid,cannot assimilate glucose,arabinose,mannose,decanoic acid,acetic acid,citric acid,benzene,etc.the strain was similar in biochemical and biophysical properties to Vibro harveyi.Compared to the similar sequences in the GenBank database,the sequence of 16 S rDNA of strain CJG01 and constructing phylogenetic evolution tree analysis shared a high similarity to that of Vibro harveyi.Based on the results obtained,strain CJG01 was identified as Vibro harveyi.2.The influence on serum biochemical indexes for C.striata: using by researching serum biochemical indicators and pathogenesis.Compared with healthy C.striata,serum total protein,albumin,triglyceride,total cholesterol,urea nitrogen content were decreased significantly in diseased larvae(P<0.05),creatinine levels increased significantly(P<0.05),no significant difference on globulin content;the enzymatic activity of lactate dehydrogenase,aspertate aminotransferase,alanine aminotransferase,lactate dehydrogenase and lysozyme were significantly enhanced(P< 0.05);serum K+ content decreased significantly of diseased larvae(P<0.05),the Cl-content increased significantly(P<0.05),the content of Na+,Ca2+,no significant difference.This suggests that diseased larvae with exophthalmic disease: muscle,liver,kidney and other organs’ injury is serious,liver function,renal function were abnormal.3.The influence on microscopic pathology for C.striata: eye swelling,containing the bladder and coagulate blood clots;muscle fiber necrosis damaged;heart sarcomere vague and erythrocytosis;liver central venous hyperemia,liver cell vacuoles degeneration,partial liver cell nucleus dissolved,a large number of lymphocytes,monocytes,infiltration in liver mesenchymal cells;spleen tissue necrosis,red blood cell rupture,hyperemia,spleen lymphocytes increase;partial mucosa cell necrosis,fundic gland loosely arranged,fundic gland cavity degeneration;a large number of inflammatory cell infiltration in the intestinal mucosa.renal interstitial had blood clot,a large number of red blood cells infiltration,glomerular capillary hyperemia,renal tubular wall cell degeneration,the nucleus dissolved;The pathological changes of the gill tissue was not significant.4.The influence onr ultrastructural pathology for C.striata: synapses interstitial hyperemia,corneal fibroblasts necrosis and collagen dissolved.Myofibril ultrastructure,H belt fuzzy,M faint,myofibril fracture,mitochondria decreased and disintegration.Myocardial fibers,H belt fuzzy,M line faint,I belt fuzzy,Z line faint,myofibril fracture.Liver cell swelling,deformation,and some liver nuclei squeezed.Cell nuclear membrane blurred,mitochondria decreased and disintegration.Rough endoplasmic reticulum fracture,the liver lipid drops fills in the cytoplasm,cell organelle dissolution,lysosome increased,part of the liver cell necrosis and apoptosis.Spleen tissue,lymphocytes decreased,organelles disintegrated,cytoplasm nuclear membrane damaged.Stomach tissue cells blurred,nuclear membrane damaged,organelles dissolved.Intestinal epithelial cells blurred,cell vacuoles.Kidney epithelial cell necrosis,nucleus dissolved,lysosomes increased,first proximal convoluted tubules’ endothelial cell necrosis.Gill filaments,cell boundaries clear,organelles were in good order,and had no obvious pathological changes.