Marek Ana, Schulz Evelyn, Hess Claudia, Hess Michael
Clinic for Avian, Reptile and Fish Medicine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine, Veterinärplatz 1, A-1210 Vienna, Austria.
J Vet Diagn Invest. 2010 Nov;22(6):937-41. doi: 10.1177/104063871002200613.
A total of 18 samples from 4 outbreaks of gizzard erosions in broiler chickens in Europe were used in the current study. Fowl adenoviruses were found in samples from all 4 outbreaks, and isolates were identified as Fowl adenovirus A (FAdV-A) serotype 1. As described earlier, polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of the long fiber gene was conducted. However, all 18 samples showed the same pattern as apathogenic FAdV-1 strains: Ote and chicken embryo lethal orphan (CELO) viruses. Nucleotide and amino acid sequences of the long and short fiber of several isolates from broiler chickens with gizzard erosions were analyzed, and 100% identity between the field isolates on the protein level was revealed. Only 1 nonsynonymous mutation (T→A) was present in the long fiber of studied isolates compared to the CELO strain. The same mutation was also present in the Ote strain. Four nonsynonymous mutations were present in the long fiber of studied isolates compared to Ote strain. In the short fiber, 6 nonsynonymous mutations were found in the studied isolates compared to the CELO strain. However, the short fiber of pathogenic isolates was 100% identical to apathogenic Ote strain. In conclusion, the usefulness of PCR-RFLP analysis of the long fiber gene of FAdV-1 isolates in distinguishing between those that induce gizzard erosions and those that do not remains questionable for the isolates obtained from European poultry flocks. The role of certain FAdV-1 strains with their long and short fiber in pathogenicity regarding gizzard erosions is still not clear.
本研究使用了来自欧洲4起肉鸡肌胃糜烂疫情的总共18份样本。在所有4起疫情的样本中均发现了禽腺病毒，分离株被鉴定为禽腺病毒A（FAdV-A）1型。如前所述，对长纤维基因进行了聚合酶链反应-限制性片段长度多态性（PCR-RFLP）分析。然而，所有18份样本均显示出与无致病性FAdV-1毒株（Ote和鸡胚致死孤儿（CELO）病毒）相同的模式。对来自患有肌胃糜烂的肉鸡的多个分离株的长纤维和短纤维的核苷酸及氨基酸序列进行了分析，结果显示在蛋白质水平上，现场分离株之间具有100%的同一性。与CELO毒株相比，所研究分离株的长纤维中仅存在1个非同义突变（T→A）。Ote毒株中也存在相同的突变。与Ote毒株相比，所研究分离株的长纤维中存在4个非同义突变。在短纤维中，与CELO毒株相比，所研究分离株中发现了6个非同义突变。然而，致病性分离株的短纤维与无致病性的Ote毒株100%相同。总之，对于从欧洲家禽群中获得的分离株，通过PCR-RFLP分析FAdV-1分离株的长纤维基因来区分诱导肌胃糜烂的毒株和不诱导肌胃糜烂的毒株的有效性仍存在疑问。某些FAdV-!毒株的长纤维和短纤维在肌胃糜烂致病性方面的作用仍不清楚。
