Davidson Irit, Nagar Sagit, Ribshtein Israel, Shkoda Irena, Perk Shimon, Garcia Maricarmen
Division of Avian Diseases, Kimron Veterinary Institute, Bet Dagan, P.O. Box 12, Israel 50250.
Avian Dis. 2009 Dec;53(4):618-23. doi: 10.1637/8668-022709-ResNote.1.
Infectious laryngotracheitis (ILT) is a respiratory disease of poultry caused by an alphaherpesvirus (ILTV). To evaluate differential detection of ILTVs belonging to the two types, wild-type or vaccine-type, both causing clinical signs, five PCRs were evaluated to detect wild-type and vaccine-type ILTV in clinical samples. By directly sampling the organs, we aimed to avoid changes in the virus genome and to facilitate a fast diagnosis. The samples were tracheal and spleen homogenates and feather shafts. The latter are easy to collect, nonlethal for the bird, and advantageous for monitoring purposes. We investigated the time interval for vaccine virus detection following commercial vaccination by the vent application, which is successfully practiced in Israel. The study indicated that ILTV amplification from feather shafts was possible in clinical cases for about a one-month period after vaccination. Vaccine strains were identified by nested PCR for the ILTV-gE gene and differed from wild-type ILTV strains by two criteria: (1) While avirulent vaccines could be detected for about a month after the vent application, wild-type virus could be detected, in conjunction with clinical signs, for an unlimited time period; and (2) The ILTV vaccine was present in the bird in minute quantities compared to the wild-type virus. We assessed the virus type that appeared in conjunction with the clinical signs and determined that the clinical signs appeared in conjunction with both molecular forms of ILTV. The vaccine virus-type and the wild-type ILTV differed by their distinct restriction pattern when using the HaeIII restriction enzyme digestion of the nested amplification product.
传染性喉气管炎（ILT）是由一种α疱疹病毒（ILTV）引起的家禽呼吸道疾病。为了评估对两种均可引起临床症状的ILTV（野生型或疫苗型）进行鉴别检测，对五种聚合酶链反应（PCR）进行了评估，以检测临床样本中的野生型和疫苗型ILTV。通过直接对器官进行采样，我们旨在避免病毒基因组发生变化并便于快速诊断。样本为气管和脾脏匀浆以及羽轴。羽轴易于采集，对鸟类无致死性，且有利于监测目的。我们研究了通过泄殖腔接种进行商业疫苗接种后检测疫苗病毒的时间间隔，这种方法在以色列已成功应用。研究表明，在临床病例中，接种疫苗后约一个月内可从羽轴中扩增出ILTV。通过针对ILTV-gE基因的巢式PCR鉴定疫苗毒株，其与野生型ILTV毒株在两个方面存在差异：（1）泄殖腔接种后约一个月可检测到无毒力疫苗，而野生型病毒可与临床症状一起在无限期内被检测到；（2）与野生型病毒相比，鸟类体内的ILTV疫苗含量极少。我们评估了与临床症状同时出现的病毒类型，并确定临床症状与两种分子形式的ILTV均同时出现。当对巢式扩增产物进行HaeIII限制性酶切时，疫苗病毒型和野生型ILTV的限制性图谱不同。
