Giambrone J J, Fletcher O J, Lukert P D, Page R K, Eidson C E
Avian Dis. 1978 Jul-Sep;22(3):451-8.
Commercial turkey poults 3 to 6 weeks old were infected experimentally by eyedrop with an infectious bursal disease virus (IBDV) inoculum obtained from chickens experiencing clinical IBD. The IBDV was passed 6 successive times in poults in an attempt to increase its pathogenicity for turkeys. Regardless of passage level, the IBDV infection in poults was subclinical, with no morbidity, mortality, or gross lesions observed. The bursae of Fabricius from infected poults, however, displayed various degrees of microscopic degeneration and IBDV specific fluorescence at 3, 4, and 5 days postinfection (PI). Infected turkeys also developed low levels of virus-neutralizing antibodies against IBDV at 12 days PI. Uninoculated poults kept in the same unit with infected poults also displayed microscopic changes and IBDV specific fluorescence 7 days after their appearance in inoculated poults. The IBDV was isolated from infected poults only after 5 successive passages of bursal material from infected poults in 9-day-old chick embryos. The IBDV from infected embryos was inoculated into susceptible 3-week-old chickens and 5-week-old poults and produced IBDV fluorescence and microscopic pathology in the bursae of infected poults and clinical IBD in infected chickens.
3至6周龄的商用火鸡雏通过滴眼接种从患有临床传染性法氏囊病（IBD）的鸡身上获得的传染性法氏囊病病毒（IBDV）接种物进行实验性感染。IBDV在火鸡雏中连续传代6次，试图提高其对火鸡的致病性。无论传代水平如何，火鸡雏中的IBDV感染均为亚临床感染，未观察到发病、死亡或肉眼可见病变。然而，感染火鸡雏的法氏囊在感染后3、4和5天显示出不同程度的微观变性和IBDV特异性荧光。感染的火鸡在感染后12天也产生了低水平的针对IBDV的病毒中和抗体。与感染火鸡雏饲养在同一单元的未接种火鸡雏在接种火鸡雏出现病变7天后也显示出微观变化和IBDV特异性荧光。仅在将感染火鸡雏的法氏囊材料在9日龄鸡胚中连续传代5次后，才从感染火鸡雏中分离出IBDV。将来自感染胚胎的IBDV接种到易感的3周龄鸡和5周龄火鸡雏中，在感染火鸡雏的法氏囊中产生IBDV荧光和微观病理变化，并在感染鸡中引起临床IBD。
