Kennedy James A, Mortimer Robert G, Powers Barbara
Colorado State University Veterinary Diagnostic Laboratory, Rocky Ford Branch, Rocky Ford 81067, USA.
J Vet Diagn Invest. 2006 Jan;18(1):89-93. doi: 10.1177/104063870601800113.
Ear-notch samples from 3,599 yearling heifers were collected to detect persistently infected (PI) animals with suspect bovine viral diarrhea virus (BVDV). Individual immunohistochemistry (IHC), individual antigen-capture enzyme-linked immmunosorbent assay (AC-ELISA), and reverse transcription-polymerase chain reaction (RT-PCR) tests with pooled ear-notch supernatants were compared with samples from 3,016 heifers, whereas RT-PCR ear-notch pools and individual AC-ELISA tests were compared with samples from all 3,599 heifers. Four heifers were identified positive by both IHC and AC-ELISA, whereas the remaining heifers were identified negative by both tests. When supernatant from ear notches from 100 animals was randomly pooled and RT-PCR was accomplished on each pool, RT-PCR identified 2 pools that contained 1 positive AC-ELISA sample and 1 pool that contained 2 positive AC-ELISA samples. Further evaluation of the pooled RT-PCR ear-notch supernatant detected 100% (n = 36) samples spiked with supernatant from a single randomly selected positive AC-ELISA ear notch. Although follow-up confirmatory tests were not completed, all 3 methods correlated 100% in detecting suspect PI animals, with a kappa value of 1. The use of RT-PCR on pooled ear-notch supernatant could provide an initial, rapid, cost-effective method of screening cattle herds for BVDV PI animals. Subsequent serial testing with an AC-ELISA to evaluate individual samples included in the positive pool could minimize the length of time other animals are exposed to the virus.
采集了3599头一岁小母牛的耳缺样本，以检测疑似感染牛病毒性腹泻病毒（BVDV）的持续感染（PI）动物。将个体免疫组织化学（IHC）、个体抗原捕获酶联免疫吸附测定（AC-ELISA）以及对合并耳缺上清液进行的逆转录聚合酶链反应（RT-PCR）检测，与来自3016头小母牛的样本进行比较，同时将RT-PCR耳缺合并样本和个体AC-ELISA检测与来自所有3599头小母牛的样本进行比较。通过IHC和AC-ELISA均鉴定出4头小母牛为阳性，而其余小母牛通过这两种检测均鉴定为阴性。当随机合并100头动物耳缺的上清液并对每个合并样本进行RT-PCR时，RT-PCR鉴定出2个合并样本中含有1个AC-ELISA阳性样本，1个合并样本中含有2个AC-ELISA阳性样本。对合并的RT-PCR耳缺上清液进行进一步评估，检测到100%（n = 36）的样本被随机选择的单个AC-ELISA阳性耳缺的上清液加标。尽管后续的确认性检测未完成，但所有3种方法在检测疑似PI动物方面的相关性为100%，kappa值为1。对合并的耳缺上清液进行RT-PCR检测可为筛查牛群中的BVDV PI动物提供一种初步、快速且经济高效的方法。随后用AC-ELISA进行系列检测以评估阳性合并样本中的个体样本，可将其他动物接触病毒的时间缩短到最短。
