Institute of Animal Pathology, Vetsuisse Faculty, University of Bern, Länggassstrasse 122, 3012 Bern, Switzerland.
Leibniz Institute for Zoo and Wildlife Research, Department of Wildlife Diseases, Alfred-Kowalke-Straße 17, 10315 Berlin, Germany.
Avian Dis. 2020 Dec 1;64(4):496-498. doi: 10.1637/aviandiseases-D20-00030.
The avian pathogen Ornithobacterium rhinotracheale (ORT) has been implied in the etiology of poultry respiratory disease in recent years. To evaluate whether Whatman® Flinders Technology Associates (FTA®) cards can be used for hazard-free transport and storage of ORT samples for posterior DNA amplification, a controlled assay was performed. Three 10-fold dilutions of an ORT culture suspension were spotted on FTA cards and stored at room temperature (RT) for 6 mo. Sterile swabs were immersed in the same three 10-fold culture dilutions and stored at RT and 4 and -20 C without storage medium for the same time. DNA was extracted from both the FTA cards and swabs 1 day, 1 and 6 wk, and 6 mo following sample preparation and stored at -20 C. At the end of the experiment, real-time PCR amplification of the 16S ribosomal RNA gene was performed from DNA extracted throughout a 6-mo period from all ORT samples stored on both FTA cards and swabs. The obtained threshold cycle values for each ORT DNA extraction date were within the same range for all samples in a dilution-dependent fashion, regardless of storage temperature or used material. Pure ORT colonies could be reisolated 1 day after sample preparation from the swab dilutions stored at all temperatures but not from the FTA cards. We conclude that the efficiency of ORT DNA amplification from samples stored on FTA cards or in swabs is similar. However, FTA cards have the advantage of preventing microorganism growth, thus allowing safe transport and storage, for at least 6 mo, for bacterial dilutions down to at least 104-105 colony-forming units/ml.
近年来，禽源鸟疫杆菌（Ornithobacterium rhinotracheale，ORT）已被认为是家禽呼吸道疾病的病因之一。为评估惠特曼滤膜技术协会（Whatman® Flinders Technology Associates，FTA）卡是否可用于 ORT 样本的无危害运输和储存以供后续 DNA 扩增，进行了一项对照试验。将 ORT 培养物悬液的三个 10 倍稀释液点样到 FTA 卡上，并在室温（room temperature，RT）下储存 6 个月。无菌拭子浸入相同的三个 10 倍培养物稀释液中，并在 RT 和 4℃及-20℃下储存，无储存介质，时间相同。在样本制备后 1 天、1 周、6 周以及 6 个月时，从 FTA 卡和拭子上提取 DNA 并储存于-20℃。在实验结束时，从所有 FTA 卡和拭子上储存的 ORT 样本中提取的 DNA 进行 16S 核糖体 RNA 基因的实时 PCR 扩增。对于每个 ORT 提取日期的获得的阈值循环值，在稀释依赖性方式下，所有样本均在相同范围内，而与储存温度或使用的材料无关。在所有温度下储存的拭子稀释液中，可在样本制备后 1 天从所有稀释液中重新分离出纯 ORT 菌落，但不能从 FTA 卡中分离出。我们的结论是，从储存于 FTA 卡或拭子上的样本中扩增 ORT DNA 的效率相似。然而，FTA 卡具有防止微生物生长的优势，从而允许至少在 6 个月内安全运输和储存细菌稀释液，至少达到 104-105 个菌落形成单位/ml。
