| Yellow catfish(Tachysurus fulvidraco)is an important freshwater economic fish in China.However,yellow catfish is the main breed in Hubei province its large individual size in recent years.However,with the rapid growth of breeding scale,its disease problem become more and more frequent.In this study,fulminant epidemic cases were collected in Jingzhou and surrounding places from liver,spleen,kidney and intestine to two dominant pathogens that were named XW1.By 16 S r RNA technical sequence alignment of Shewanella putrefacens,the semi-lethal concentration was LD50=2.95 × 105CFU/m L,and XW1 was determined as the pathogen of the fulminant epidemic.Its gram stain was negative,physiological and biochemical indexes and 16 S r RNA technical sequence ratio were finally determined to be S.spoilage.On the one hand,through drug susceptibility experiments,it was found that it is highly sensitive to norfloxacin,tetracycline,ofloxacin and flufenicol,and on the other hand,with the inactivated Shewanella vaccine,the best inactivated conditions were: inactivation at a concentration of 0.5% formalin at a temperature of 28℃.The inactivated vaccine was 60%.GSH-Px,LZM,MDA.TP at 1.3.5.9.11.13 d,C3,Ig M,IL-1,IL-6,and TNF-α.The results are as follows:After F-XW1,GSH-Px was higher than controls(P <0.05),and data on days1,3,5,7,9,11 and 13 revealed that 1 d except 11dy(P <0.05);3 d and 5 d and 9 d,7 d and 9 d.After immunization,glutathione peroxidase(GSH-Px)showed a trend of rising first and then decreasing,reaching its peak at day 7.Lysozyme(LZM)varied significantly at 1 d,3 d,5 d,7 d,and 9 d from controls(P <0.05).There were significant differences in 1,3,5 and 11 d on days 1,5,7,9,11 and 13(P <0.05),and the overall change was not very obvious.T-SOD was significantly different in the first three times: 1 d,3 d,and 5 d(P <0.05),including the first three days(1,3,5,7,9,11,and 13 d(P <0.05)and the last four times(7,9,11,13).The overall T-SOD rose rapidly first and then decreased to flattening.MDA F-XW1 vaccine immunization group except 1 d and the control group showed significant changes(P<0.05).Between days 1,3,5,7,9,11 and 13,1 d and 3,5,7,11 and 13 d(P <0.05),1 d,5d and 7 d and 9 d(P <0.05)and 11 d and 13 d.TP was significantly higher(P <0.05);between days 1,3,5,7,9,11,11,13,1d and 11d(P <0.05),2d and 5 d,7 d,7 d,11 d and13 d(P <0.05),5 d and 7 d,11 d,13 d and 7 d(P <0.05),total protein increased.After F-XW1 immunization against yellow catfish,complement C3,tumor necrosis factor-α(TNF-α),interleukin 1(IL-1)(IL-6)were detected by q RT-PCR method(P <0.05)Liver: Data 1,3,5,7,9,11,13 were significant as follows: complement C3,1 d and 6d,2 d and 5 d were not significant between the remaining data(P <0.05).complement C3 was gradually increasing.TNF-α,not significant between 3 d and4 d,5 d and 5 d and 6 d,was significant between the remaining data(P <0.05).On the overall rise.Lysozyme(LZM): no significant gap between 5 d and 7 d,and the rest were significant(P <0.05).there is a trend of rise first and then decline.IL-1: There were significant differences between the data(P <0.05),rising first,then falling and then rising in these fourteen days.IL-6: no significant difference between 3 d and 6 d,and all others were significant(P <0.05).Peak by 7d and subsequently decreased.Spleen: The significance analysis of data 1,3,5,7,7,9,11 and 13 was as follows:there were significant differences between complement data,C3,1 d,3 d,5 d,7 d,9d,11 d and 13 d(P <0.05).Overall,complement C3 was gradually increasing.TNF-α,which was not significant between 4 d and 6 d,and showed significant differences between the remaining data(P <0.05).On the overall rise.Ig M:significant differences(P <0.05).there is a trend of rising first,then falling first and then slowly rising first.IL-1: There were significant differences between the data(P<0.05),rising first,then falling and then rising in these fourteen days.IL-6: no significant difference between 6 d and 7 d,all(P <0.05).The overall trend shows an upward trend.Head and kidney: data 1,3,5,7,9,1,11,13 were significant as follows: complement C3(P <0.05)from 1 d,5 d,7 d,9 d,11 d,13 d,and no significant difference from 2d.There were no significant differences between 3 d and 5 d and 7 d,4 d and 7 d,or5 d and 6 d.complement C3 showed a downward trend after increasing.TNF-α,with a significant difference between each data(P <0.05).On the overall rise.LZM:each data varied significantly(P <0.05).there is an upward trend first.IL-1: there were significant differences between 1 d and each data(P <0.05),2 d and 7 d,3 d,4d,4 d,4 d and 6 d,and then in these fourteen days.IL-6: no significant difference between 1 d and 2 d,4 d and 6 d,and all other significant differences(P <0.05).The overall trend shows an upward trend.Vaccine is one of the acute stresses that force changes in the corresponding indicators of fish body serum.In this study,the relevant enzyme activity and total protein changes of the serum were measured,and the inactivated vaccine had significant effects on the total protein,antioxidant ability and nonspecific immune index.In general,when this problem occurs in the breeding process,this study provides some reference to solve the problem,and provides a feasible way for the development of yellow catfish bacterial vaccine in the future. |
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