Keeler C L, Hazel J W, Hastings J E, Rosenberger J K
Delaware Agricultural Experiment Station, Department of Animal Science and Agricultural Biochemistry, College of Agricultural Sciences, University of Delaware, Newark 19717-1303.
Avian Dis. 1993 Apr-Jun;37(2):418-26.
Restriction endonuclease (RE) digestion patterns of six Delmarva field isolates of infectious laryngotracheitis virus (ILTV) were compared with three standard reference strains. With one exception, all of the field isolates generated RE digestion patterns identical to an embryo-propagated vaccine strain of ILTV when the six-base-recognizing REs EcoRI, HindIII, PstI, and BamHI were used. In order to increase the sensitivity of the RE analysis technique, a more sensitive DNA fingerprinting approach using four-base-recognizing enzymes was developed. One field isolate could be differentiated from the embryo-propagated vaccine strain using all three enzymes, Sau3AI, MspI, and HinfI. A second isolate could be differentiated only by comparing HinfI digestion patterns. This work provides additional evidence that differentiable strains of ILTV exist in the United States. Furthermore, currently used RE analysis methods may not be sensitive enough to discriminate between field isolates and vaccine strains of ILTV, thus challenging the theory that vaccine strains of ILTV are responsible for field outbreaks of infectious laryngotracheitis.
将六种德尔马瓦地区传染性喉气管炎病毒（ILTV）野外分离株的限制性内切酶（RE）消化模式与三种标准参考毒株进行了比较。除了一个例外，当使用识别六碱基的REs（EcoRI、HindIII、PstI和BamHI）时，所有野外分离株产生的RE消化模式都与一种胚胎传代的ILTV疫苗株相同。为了提高RE分析技术的灵敏度，开发了一种使用识别四碱基酶的更灵敏的DNA指纹图谱方法。使用Sau3AI、MspI和HinfI这三种酶，可以将一种野外分离株与胚胎传代的疫苗株区分开来。另一种分离株只能通过比较HinfI消化模式来区分。这项工作提供了额外的证据，表明在美国存在可区分的ILTV毒株。此外，目前使用的RE分析方法可能不够灵敏，无法区分ILTV的野外分离株和疫苗株，从而对ILTV疫苗株导致传染性喉气管炎野外暴发的理论提出了挑战。
