Dynamic Pathology And Pathogen Distribution Of Pelteobagrus Fulvidraco Infected By Edwardsiella Ictaluri

This test using intraperitoneal injection, immersion challenge and oral infection3ways artificially infected the Pelteobagrus fulvidraco (45±3.5g) with Edwardsiella ictaluri (E. ictaluri), with the researches of dynamic pathology and pathogen distribution in tissue to reveal the distribution of E.ictaluri in infected Pelteobagrus fulvidraco and the corresponding pathological characteristics of various organs.360yellow catfish were divided into6groups, each group of60, respectively to E.ictaluri after intragastric and intraperitoneal injection, soak for artificial infection of3ways, setting the same infection-controling group. After infection, respectively2h、4h、8h、12h、24h、48h、72h、96h.......4sampling in each set were collected randomly, slicing technique for pathological and immunohistochemical study on morphology and distribution of pathogens in your organization. Found that injection and immersion clinical symptoms of infection12h-24h start after a slight, mainly for swimming on the surface of the water slowly, floating head,48h-72h swim slowly, very easy to catch, reduced body balance and a spiral walk, abdominal enlargement, abdominal ascites due to a lot of pink, anal irritation, gonads and fin at the base of patients, bleeding. Infection occurs after the48h after intragastric appetite, moving activity reduces, sometimes spin swim sometimes adherent does not move, and deaths began to emerge, the dead fishs were stomach fluid, bleeding, abdominal has a large number of ascites.On the pathological histology, the contrasts of infected fish liver, spleen, kidneys, heart, intestines, skin and stomach muscles and other tissues and organs show different levels of congestion, hemorrhage, necrosis and inflammation, but most serious liver, kidney and spleen. Early liver cells swell, blister degeneration; later generalized degeneration occurs, or necrosis, dissolve, a large number of inflammatory cell infiltration. Mainly lesions for the early the glomerular capillary endothelial cell swelling, granular degeneration of renal tubular epithelial cells and tubulointerstitial macrophage and neutrophil infiltration; later kidney hematopoietic tissue necrosis, bleeding, severe renal tubular epithelial cells vacuoles disintegration degeneration and necrosis. Mainly for congestion in the early days of the spleen, bleeding, a small amount of hemosiderin; later mainly lymphocytes necrosis, significantly reduced the number, and a large number of macrophage infiltration of neutrophils. Super micro-structure Shang, liver cell mitochondrial swelling, Ridge fracture dissolved, cell pulp within fat drops increased, cell within and cell between appears large bacteria; kidney small tube epithelial cell mitochondrial swelling, within mass network expansion, in some epithelial cell due to disease original bacteria of intrusion to necrosis, kidney between mass organization clearance and macrophages within appears large pathogens intrusion; spleen within lymphocytes number clear reduced, lymphocytes nuclear chromatin concentrated, edge moved, nuclear film expansion, macrophages increased, cell within swallowed large pathogens.Immunohistochemical detection of discovered the main exhaust dyeing of pelteobagrus fulvidraco in the liver, spleen, and kidneys. Positive signals primarily located in the sinus walls of sinusoids of the liver, liver cells, macrophages, kidney and renal interstitial tubular epithelial cells and macrophages, Gill, stomach, brain, and other organs are also weakly positive signal is detected.The results of E. ictaluri distribution in infected Pelteobagrus fulvidraco tissues and pathological changes showed there were positive correlations between the E. ictaluri distribution in Pelteobagrus fulvidraco tissues and pathological injury.