中文摘要：

近几年,家禽发生多种病原共感染的现象非常普遍,多种病原共感染常常引起非典型的病变,并进而导致重大的经济损失。细菌性胚胎性疫病病原种类较多,且大多是条件性致病菌,由不同的细菌多重感染诱发的疾病越来越常见,鸡毒性支原体（Mycoplasma gallisepricum,MG）、鸡沙门氏菌（Salmonella Avium）、禽波氏杆菌（Bordetella Avium）为三种常见鸡胚胎细菌性疫病的病原。因此,本研究针对这三种常见鸡胚胎细菌性疫病的病原进行了共感染的分析与检测。目的在于研究这三种微生物的共感染的发病情况、病理变化、病原微生物的分布及其消长规律,以及与单独感染的差别。通过本研究为鸡场中此类疾病提供理论依据。方法：分别对1日龄SPF雏鸡（10只/组）和11日龄SPF鸡胚（10枚/组）进行3种病原、2种病原、1种病原的感染。随时进行生长情况的观察,对死亡雏鸡、鸡胚进行剖检。结果,无论通过肉眼观察和还是病理学观察,3种病原共感染的雏鸡和鸡胚病变最严重,出现死亡时间最早,并且死亡率最高,两种病原共感染次之,但是多种病原共感染情况都比一种病原单独感染严重。为了进一步研究发生共感染之后,病原的分布及其随时间的消长规律,分别对剖检雏鸡与鸡胚取样,进行IFA与PCR的检测,结果表明,支原体的侵袭,气囊感染最严重,肾脏次之,其后是肝脏。波氏杆菌与沙门氏菌在肝脏和法氏囊感染最严重,肾脏和肺脏次之,另外,对于波氏杆菌感染鸡,从皮下也有大量病原菌存在。雏鸡在感染24 h内各病原含量呈快速增长趋势,36 h之后达到高峰,然后下降,在三种病原共感染的雏鸡的组织中,每种病原的含量与单独感染、双重感染的含量相差不大。鸡胚在感染24 h内各病原含量呈增长趋势,24 h之后下降,多种病原共感染的鸡胚分离得到的单独一种病原的含量略低于单独感染的鸡?

英文摘要：

In most condition,it is very common occurrence that the avians coinfect with two or more pathogens.The manner in which multiple pathogens interact is not always straightforward,however the disease of avian embryo is a synthetical disease which can cause the increase of embryo death and decrease of incubation rate and is fatal to economy.There are many species of the disease of avian embryo,and most is conditional pathogenic bacteria.Mycoplasma gallisepricum,Salmonella Avium and Bordetella Avium are three disease of avian embryo.Thus,the study to aim directly at the coinfection of these three disease of avian embryo.In an initial experiment,the effect of coinfection of Mycoplasma gallisepricum,Salmonella avium and Bordetella avium was examined in seventy,1-day-old chicken（10 chicken /group） and seventy,11-day-old embryos（10 mbryos/group） edu.cn that were infected with the three pathogens or two pathogens or only one pathogens.An additional 10 chicken and 10 embryo served as sham infected controls.Observe the growth and death of the chicken and embryo.When they die,dissect the dead bodies.The results： The symptom of the coinfection of the three pathogens is the most serious,the death time is the most early,the death rate is highest,and the next in order is the dually infected chicken and embryo.In order to investigate the potential trend in disease severity after coinfection,a second experiment was performed to examine the pathogens by IFA and PCR in tissues from single and dually infection and triplicate infection.The results： the contect of MG is highist in aerocyst,Salmonella avium and Bordetella avium is in Liver and bursa.when it is 36 h,the contect of pathogens is highest in chicken and ahout 24 h in emobryo.To further study the cause of disease of avian embryo,epidemiological investigation pathogenic studies and PCR to main pathogens were done,supplying the theoretical foundation to the prevention of avian embryo in large-scale AA broiler breeder farm.