Epidemiologic Survey And Prevention And Control Of Chicken Colibacillosis In Taiyuan Surrounding Areas

Colibacillosis is an important bacterial infectious disease which seriously harms chicken industry..The enlargement of the raising scale give rise to more of the disease,which brings heavy loss to local ecomomy. Avian colibacillosis is a partial or constitutional infectious disease which is caused by E.coli, with complicated antigens, multiple serotype and various clinical symptoms. Therefore,we firstly isolated the avian pathogenic E.coli from infectious poultry in TaiYuan and surrounding areas, and analyzed the sterotypes, drug tolerence and pathogenicity, From the basis we studied the combination and coordination of sensitive drugs and environment disinfection,and made systematic prevention measurements.The experiments of this essay contains three main parts as follows:Experiment one:E.coli strains were isolated from sick chickens which have pathological changes in a number of poultry yards in TaiYuan surrounding areas, Then the samples were cultured,purified and tested under microscope by cornrnon methods. The result of biochemistry test isolated131strains of chicken patogenicitial E.coli strains. From which114strains and21serogroups were isolated. Among these serogroups, O78,O1,O2and068were superior serogroups, and these four serogroups took the percentage68.42%of114isolates.80isolated strains were used to vaccinate one days young chickens. Both clinical symptome and pathological changes were in keeping with the characteristics of E. coli.123strains of colibacillosis were definite which were pathogenicity strains in final.Experiment two:K-B paper method was adopted to make susceptibility test with92isolated strains. The results of susceptibility tests showed that the drug tolerence of the isolated strains was rather strong. The bacteria isolated only showed high sensitivity to Ceftriaxone sodium, Neomycin sulfate, Amikacin, Fosfomycin, Cefazolin, Apramycin and so on, and the higher sensitivity rate were62.0%-83.7%.Experiment three:Through the experiment which was made to choose the disinfectant of superior serotypes,the results showed that Formaldehyde, Sodium hypochlorite, Peracetic acid, and Quaternary ammonium salts stranded could kill the E.coli of four superior serogroups effectively in10minutes without Iodine preparations. Sodium hypochlorite, Peracetic acid and Double-stranded quaternary had the desired effects which could have the100%sterilization rate to four superior serogroups in20minutes.In addition,the sterilization rate of Formaldehyde was99.7%in30minutes.The results that the avian pathogenic E.coli which were isolated from infectious poultry in TaiYuan and surrounding areas had the feature of multiple serotype, the strong drug tolerance and the diversity of drug tolerance. Therefor, developed the prevention measurements of combination of vaccine to prevent、sensitive drugs and environment disinfection,and provided a scientific basis for the prevention and treatment of this disease.