| In the present study,Chinese medicines with good bacteriostatic action and had cerain effects of increasing efficaty of antibacterial were screened out,and they were used for candidates for the later prescriptions.Furthermore,the protecitvie effects and mechanisms of prescription of Yuzhi Powerd,consisting of Sanguisorba officinalis L.,Gardenia,and Rhubarb,was assessed It could provide a basis for treatment application of poultry colibacillosis1.According to CLSI,the MIC of several major antibiotics commonly used in Enterobacteriaceae was tested in 16 isolates Escherichia coli from chickens with suspected colibacillosis in chicken farm of Linqu,Shandong province,and the drug-resistant strains produced ESBLs were detedted according to CLSI recommended primary screening and confirmatory tests.Furthermore,the genotype of ESBLs was detected by PCR.The results showed that all 16 isolates contained drug resistance genes,and seven of which contained two drugresistance genes,three of which contained three drug resistance genes,and all strains produced ESBLs.Moreover,the resistance rates of these strains to cefotaxime sodium,ceftriaxone sodium,ceftazidime,amoxicillin and etc were as high as 100%,and there were different degrees of resistance to other antibacterial drugs.2.The sub-inhibitory concentration of 12 traditional Chinese medicines(TCM)and antibiotics were combined to gradually induce the resistant Escherichia coli for passage,and the effect of alternative medicine on the MIC of the antimicrobial drug-resistant E.coli was assessed.The medicines that has the effect of inhibiting the drug-resistant E.coli were used to form a prescription named Yuzhi Powerthat composed of Andrographis paniculata,Scutellaria baicalensis Georgi,Dendranthema indicum.Then,the effect of Yuzhi Power on the change of MIC of drug-resistant E.coli was tested.The result showed that Yuzhi Power could increase the antimicrobial activity of penicillin,cephalosporin,and fluoroquinolone et al.3.The 10-day-old broiler chickens were stimulated with drug-resistant E.coli,and were treatment with Yuzhi Power and Pulsatilla Root Power.The results showed that the clinical effect of Yuzhi Power was significant,especially in the high-dose group and the middle-dose group,and the effective rate and the cure rate were 90.0% and 83.3%,respectively.The corresponding positive control formula,Pulsatilla Root Power,had a relatively weak therapeutic and protective effect,and its effective rate and cure rate for diseased animals were only 73.3%,respectively.It further showed that the treatment and protection effect of Yuzhi Power on the animals infected with E.coli is better than that of Pulsatilla Root Power.4.According to the ultrastructural changes of cell wall,the change of AKP content in bacterial liquid,the change of extracellular soluble protein content,the change of total bacterial protein and the influence of bacterial DNA,the antibacterial effect of Yuzhi Power was analyzed.The results clarified that the antibacterial mechanism of Yuzhi Power water extracts against E.coli is that it could improve the contents of extravasation by increasing the cell wall and cell membrane permeability and inhibit or disorder the DNA replication of E.coli.5.To assess the protective effects of Yuzhi Power on chicken colobacillosis caused by drug-resistant Escherichaia coli in clinical,a total of 1058 chickens infected with drug-resistant Escherichaia coli that from five chicken house were treated with Yuzhi Power and Pulsatilla Root Power.The results showed that Yuzhi Power had a good curative effect on chicken colibacillosis caused by drug-resistant E.coli,with an average cure rate of 91.6% and an effective rate of 89.3%.The treatment and protective effect of Yuzhi Power on chicken colibacillosis caused by drug-resistant E.coli are 7.9% and 6.0% higher than that in Pulsatilla Root Power treatment group.It lays a basis of Yuzhi Powe application for poultry colibacillosis treatment in chichen farm. |
