几种病毒与禽病原性大肠杆菌的人工联合感染

以2种剂量的低致病性禽流感病毒(lowly pathogenic avian influenza virus,LPAIV)，传染性支气管炎病毒（infectious bronchitis virus,IBV)疫苗株H120和H52，新城疫病毒（Newcastle disese viurs,NDV)Lasota株分别于气管内注射10日龄易感鸡，2d后，气管注射禽病原性大肠杆菌O37株（O78），连续观察5d，结果，除LPAIV单独感染组有6．25％的死亡率外，其余各病毒单独接种组均健活；大肠杆菌O37株单独接种组的死亡率为62．50％，较高剂量的LPAIV，IBV H120和H52，NDV Lasota株与大肠杆菌O37株有效强的协同致病作用，死亡率分别达到81.25%,100.00%,93.75%和87.50%，而较低剂量的上述病毒则无明显的协同作用，IBV，NDV疫苗株与大肠杆菌联合接种组的多数死亡鸡病程推迟。

Experimental Infection of Chickens with Different Viruses and Pathogenic Escherichia coli of Chicken Origin

By inoculating to 10 day old chickens intratracheally with lowly pathogenic avian influenza virus(LPAIV),infectious bronchitis virus(IBV) vaccine strains H52 and H120,Newcastle disease virus(NDV) vaccine strain Lasota,two days later,the pathogenic Escherichia coli O37(O78) was inoculated by the same way.The chickens were inspected twice daily for 5 days(deaths seldom occurred after that time).The results suggested that all the chickens given the above mentioned viruses alone remained well,except the LPAIV infection group which experienced the mortality rate of 6.25%;the group given the pathogenic Escherichia coli strain O37 alone exhibited the mortality rate of 62.50%.LPAIV,IBV H120,H52 and NDV Lasota with higher doses were implicated in all the mortality that occurred in the groups of chickens given the Escherichia coli strain O37,the mortality rate was 81.25%,100.00%,93.75% and 87.50% respectively.Meanwhile,those with lower doses had no obivious effect on the colibacillosis that was produced.In these groups,most of deaths from combination inoculation of IBV H120,H52,NDV Lasota and Escherichia coli strain O37 tended to occur later in the infection than did in chickens that had been given Escherichia coli alone and the combination of LPAIV and Escherichia coli .