Study On Isolation, Identifiction, Biological Characteristics And Drug Resistance Of Eimeria Tenella Of Xining Strain

Chicken coccidiosis is a severe parasitic disease caused by a protozoan belonging to the Phylum Apicomplexa.The pathogens belong to the genus Eimeria,of which E.tenella is the most pathogenic,and severely endanger poultry industry throughout the world.We have selected the precocious strain and studied on isolation,identification,biological characteristics and drug resistance of E.tenella Xining strain and hope this work can provide the basic information for further researches.The results showed as follows:1.Using single oocysts isolation technique,we have gained pure species of Eimeria tenella from mixed species of chicken coccidia in Xining.Some indexes of oocysts,including shape,parasitic position,structure and prepatent period were.The results showed that,the shape index is 1.22,the shortest spolulation time is 18 h,and prepatent period is about 114 h. The oocyst of Eimeria broadly ovoid,15.00-26.25μm×12.50-20.75μm,average 20.08μm×16.55μm.Therefore it was identified as E.tenella of Xining strain(Et XN).2.Study on E.tenella Xining strain in chickens as focused on the characteristics according to isolated pure species and breeding.The oocyst was ovoid in shape.Oocysts were 20.08μm×16.55μm in average,and the shape index was 1.22.The minimum sporulation time was 18 h,and the prepatent period is 114h.To study the pathogenicities and pathogology, chickens were infected with 5×10~4 oocysts of E.tenella per chicken,were clinical symptom, gross pathology,and pathological histology,average weight gain,lesion score and mortalityes. The results showed that the clinical symptom and gross pathology were evidence and the reproductive potential was 6.34.In all infected groups,the weight gains were significantly different from that of control group(P＜0.05),and the lesion score were significantly different from that of control group(P＜0.01).3.13-day-old healthy chickens were inoculated with E.tenella Xining strain,to study drug resistance on diclazuril,maduramicin aminonium premix,sulfachoropyridazine and amprolium hydrochloride.Determining indexes based on the anticoccidial index(ACI), relative oocyst production(ROP),percent of optimum anticoccidial activity(POAA) and reduction of lesion scores(RLS).The results showed as followes:Xining strain were light resistant to maduramicin ammonium premix,middle resistant to sulfachoropyridazine, complete resistant to diclazuril and amprolium hydrochloride.4.The drug resistance of E.tenella Xining strain was also studied with self-designed Chinese herb compared with sulfachoropyridazine.Indexes based on the relative oocyst production(ROP),reduction of lesion scores(RLS),percent of optimum anticoccidial activity (POAA) and.anticoccidial index(ACI).The results showed as followes:Xining strain were light resistant to Chinese herb,middle resistant to sulfachoropyridazine.