Elementary Studies On Effect And Mechanism Of Qinqiao Oral Solution On E.coli O₇₈ Disease In Chicken

Through pretest, Qinqiao Oral Solution made of Chinese medicinal herbs with good bacteriostastic activity on E. coli O₇8was screened out. Then, 231 chickens with 21 days old were used as experimental animals, which were divided into seven groups at random, the control group, the challenge group, high-dose Qinqiao group, medium-dose Qinqiao group, low-dose Qianqiao group, Enrofloxacine group, and Enrofloxacine plus Qinqiao group, to observe the effects of Qinqiao Oral Solution on the treatment of artificial infected E. coli disease. In addition, 120 chickens with 27 days old were used being divided into 6 groups. At the 6h, 12h, 24, 48h, 72h and 96h after challenge with E. coli O₇8, 6 chickens from each group were selected at random and 5 ml blood was drawn from each chicken for the measurement of NO and TNF- α in the serum. The results are as follows:1. Qinqiao Oral Solution, as well as its components coptidis rhizoma, scutellaria, forsythia suspensa and granati cortex can restrain the growth of E. coli O₇8, and their MIC are respectively 208, 167, 167, 104 and 125 mg/ml, indicating that Qinqiao Oral Solution and its components have good bacteriostastic activity on E. coli O₇8.2. There were still chickens dead in the challenge group 120-244 hours later after challenge in the challenge group, 96 hours in the Enrofloxacine group, 72 hours in the low-dose Qinqiao group, 48 hours in the high-dose, medium-dose and Enrofloxacine plus Qinqiao groups. The numbers of chickens that have parahepatitis, pericarditis and peritonitis in the Qinqiao groups with different doses and Qinqiao plus Enrofloxacine group are significantly lower than that in the challenge group (p<0.01) and Enrofloxacine group (p<0.05), suggesting that Qinqiao Oral Solution has good effects on the artificial infected E. coli disease in chicken.3. Twelve hours later after challenge, the levels of NO and TNF- α in the chickens of the challenge group are significantly higher than that of the control group, showing that NO and TNF- α are two important factors to induce the inflammations in E. coli disease in chicken.4. From 12 hours after challenge until the end of the experiment, the NO level of the Qinqiao group with three doses was significantly lower than that of the challenge group, as well as the TNF- α level was significantly lower than that of the challenge group, 12, 24, 48 and 120 hours later after challenge, indicating that decreasing the levels of NO and TNF- α to decrease the inflammation is one of the mechanism of Qinqiao Oral Solution in the treatment of E. coli disease in chicken.