Application Of Chinese Herbal Medicine Ultrafine Powder In Prevention And Treatment Of Pathogenic E.coli From Chicken

The most pathogenic serotypes of local strains QH1(O₇₈)was screened as the pathological model conducting the antibacterial test in vitro of single herbs to select the effective prevention and treatment of chicken pathogenic E.coli disease of Chinese herbal medicine powder.According to all kinds of Chinese herb compatibility in the monarch,minister,assistant and the pharmacological properties and theory of syndrome differentiation of chicken pathogenic E.coli disease,single Chinese herbal medicine which was sensitive to bacteriostasis in vitro was confirmed as remedium cardinale.The best antibacterial Chinese herbal medicine ultrafine powder was selected by bacteriostatic test in vitro and artificial infection animal experiment.14-&-49-day-old chicks were artificial infected by E.coli to test the effects of compound Chinese herbal medicine ultrafine powder.And the result of indexes of immune function and serum biochemical indexes were tested to reveal the mechanism of action.The safety of compound Chinese herbal medicine ultrafine powder was evaluated by acute and subchronic toxicity tests.The resules were as follows:1.A total of 46 strains of E.coli were pathogenic E.coli from 56 strains of E.coli which were isolated from chicken farms in Qinhuangdao area.These pathogenic E.coli accounted for 82.1% in all 56 strains E.coli,and belonged to 11 kinds of serotypes(O₇₈,O89,O142 and O1 were the predominant serotypes)with 16 different virulence genes.The most pathogenic serotypes of local strains QH1(O₇₈)was screened,according to the results of animal pathogenicity test,serotype and virulence gene of E.coli.The LD50 of 1-14-and-49-day-old chicks were 3.16×106 CFU/mL,1.07×107 CFU/mL and 5×108 CFU/m L.2.The vitro antibacterial test of single Chinese herbal medicine was conducted by perforated agar plate method and the modified trace two fold dilution plate method.Coptis,honeysuckle,ebony,schisandra were extremely sensitive to Chicken Pathogenic E.coli strain QH1(O₇₈),QH2（O89）,QH4（O1）from 26 kinds of Chinese herbal medicine.The inhibition zone diameter between 20.3²2.7 mm,MIC in 15.65³1.25 mg/mL.3.The herbal ultrafine powder compound was screened by the theory of syndrome differentiation in Chinese Veterinary Medicine of chicken pathogenic E.coli disease and various pharmacological properties of chinese herb with 5 combinations of herbal compound.The best antibacterial effect of compound III was screened by bacteriostatic test in vitro and artificial infection animal test.4.Compound Chinese herbal medicine powder（compound III）infected with 14,49 day old chicken pathogenic E.coli control test.The results showed that the mortality in group C（ceftiofur sodium for 1% bird）and group D^F（1.5%,2%,2.5% added）was significantly lower than that of group B（positive control group）,while the prevention and treatment in E^F group were higher than those in group B and group C.The group E showed the best prevention effect for the pathogenic E.coli disease in 14-and-49-day-old chicken where the protective rates were 86.7% and 90%,the cure and effective rate were 92.9%,90%,89.7%,93.3%,respectively.5.Compound Chinese herbal medicine powder（compound III）was detected by the biochemical indexes and immune function of pathogenic E.coli which was from artificial infected 14-day-old chicken’s serum.In group A^F,blood related indexes were detected after 7,14,21 d,respectively.The results showed that the group E（2% compound III）had the best effect,could improve the immunity of protein level of IgG,IgM and IgA in the serum,increased the content of serum LZM,TP,GLB,GOT,reduce the levels of TG,TC,BUN contents.6.The results of acute toxicity test showed that compound III had no acute toxicity and side effects to chicken,and the maximum to lerated dose was more than 25g/（kg·d）.The results of subchronic toxicity test showed that compound III was safe for long-term use.