鸡毒支原体人工发病封闭模型的建立

Establishment of the Model for Mycoplasma gallisepticum Infection

在透明塑料隔离器中，分别制造３０～１００ｍｇ／Ｌ的氨环境，观察其对ＳＰＦ“来杭鸡”的应激反应，结果氨浓度在８５ｍｇ／Ｌ以上时，鸡群发生严重伤害，而氨浓度在５０ｍｇ／Ｌ以下时则缺乏明显应激。氨环境作应激因素，对３０日龄无特定病原ＳＰＦ鸡以鸡毒支原体强毒株作人工发病，１２天后检查气囊病变，发病率为７５％（３／４）；以鸡新城疫病毒（ＮＤＶ）、鸡传支病毒（ＩＢＶ）弱毒诱导，人工感染发病率为５０％（２／４）；经ＮＤＶ、ＩＢＶ弱毒诱导和７０ｍｇ／Ｌ的氨应激的联合作用，ＭＧ人工感染的致病率达１００％（７／７）。由此在隔离器内初步建立了鸡毒支原体人工发病的封闭模型。

In order to find the proper concentration of ammonia for inducing stress, the reactions of SPF “Leghorn chickens” in isolators containing ammonia ranging from 30 to 100 mg/L were observed. Moderate stimulation appeared in 70 mg/L ammonia, it had harmful effect on SPF Leghorn chickens when being over 85 mg/L, but when ammonia was less than 50 mg/L, it had no apparent effect. 30 day old SPF Leghorn chickens were challenged by ocular instillation and left thoracic sac instillation with the W 3 and Hs virulent strains of Mycoplasma gallisepticum (MG) under different conditions, and no significant air sac lesions were found 12 days after being challenged with MG only in 4 pullets. But air sac lesions were detected in 75%(3/4) of MG challenged pullets with 70 mg/L ammonia stress or in 50%(2/4) of MG challenged pullets pre inoculatd with attenuated NDV and IBV. The apparent air sac lesions, however, were found in 100%(4/4) of pullets which were challeged with 70 mg/L ammonia stress and were pre inoculated with attenuated NDV and IBV. This was a primary try to establish a model for MG infection in the isolators.