雏鸡烟曲霉菌感染模型的建立及人工继发大肠杆菌感染

Chickens infected with Aspergillus fumigatus are susceptibe to artificial secondary infection of Escherichia coli

为建立雏鸡的烟曲霉菌人工感染模型,探讨烟曲霉菌感染雏鸡对大肠杆菌是否更易感。本试验以烟曲霉标准菌株1×107 CFU/mL的孢子悬液,经滴鼻、灌服、气管滴注、气囊注射4种方法人工感染14日龄雏鸡,通过观察受试鸡的临床症状、病理变化判断烟曲霉菌人工感染的最佳途径,在此基础上对雏鸡人工感染大肠杆菌,通过比较大肠杆菌单纯感染组和霉菌继发大肠杆菌感染组雏鸡的死亡率及心、肝等主要器官的载菌量,判定烟曲霉菌感染雏鸡对大肠杆菌的易感性。结果显示,通过气管滴注及胸部气囊注射两种途径均能够成功地使烟曲霉菌感染雏鸡,但考虑操作的简单性,气囊注射途径为首选;在本研究中,0.1mL的1×10^7 CFU/mL的孢子悬液为烟曲霉菌气囊注射的最适感染剂量;雏鸡在烟曲霉菌感染的基础上,更容易继发大肠杆菌感染。本试验成功地建立了雏鸡的烟曲霉菌人工感染模型,确定了烟曲霉菌感染雏鸡对大肠杆菌的易感性。

To establish a model of artificial infection of chickens with Aspergillus（A.）fumigatus and explore the susceptibility of A.fumigatus-infected chickens to Escherichia coli.14 days old chickens were challenged by nasal intubation drip,perfusion,tracheal injection and intra-air sac inoculation with the concentration of 1×10^7 CFU/mL of A.fumigatus spore suspension.And we choosed the best way to infection chickens with A.fumigatus by observing the clinical symptoms and pathological changes.On this basis,secondary infection of Escherichiacoli was carried out to compare the mortality of chickens and bacteria contents in immune organs,target organs between A.fumigatus-infected chickens and A.fumigatus secondary infection of Escherichiacolichickens.The results showed that the model of A.fumigatus infection was successfully established by the method of tracheal injection and intra-air sac inoculation.However,the best way and dose of artificial infection was intra-air sac inoculation with 0.1 mL（1×10^7 CFU/mL spore suspension）after considering the the feasibility of the operation.Furthermore,chickens were more susceptibility to secondary Escherichia coli infection after infecting with A.fumigatus.So,we successfully established a model of artificially infection of chickens with A.fumigatus and the susceptibility of chickens infected with A.fumigatus to Escherichia coli was determined.