Avian polyomavirus及Psittacine beak and feather disease virus感染症,二者皆為鸚鵡類常見病毒性疾病。Avian polyomavirus (APV),屬於Papovaviridae之Avipolyomavirus,能引起年幼鸚哥之急性致死性疾病,又稱為小鸚哥病(budgerigar fledgling disease; BFD) ,其致死率可高達100%。 Psittacine beak and feather disease virus (PBFDV),屬於Circoviridae之Circovirus,可感染約六十種的野生及寵物鸚鵡,其臨床上會出現慢性進行性脫羽,在某些鳥種,會出現鳥喙及爪部生長畸形情況。在本研究以聚合酶連鎖反應(Polymerase chain reaction, PCR)檢測樣本中,avian polyomavirus (APV) 檢測陽性率為28.8% (21/73),psittacine beak and feather disease virus (PBFDV) 檢測陽性率為55.1% (38/69) ,而混合感染陽性率為24.6% (17/69)。將部份核酸產物經選殖定序後,與基因庫(GeneBank)之序列比對,台灣各株APV之VP1基因核酸序列與基因庫之APV核酸序列比對,則相似度93.1-100% ,APV另一T antigen coding region片段核酸序列與基因庫之APV核酸序列比對,則相似度90.1-99.1%。台灣各株PBFDV之ORF1核酸序列相似度與基因庫中美國、澳洲之PBFDV核酸序列比對,則相似度87.5-97.3%,另一C1片段核酸序列與基因庫之PBFDV比對相似度86.5-98.4%。根據其核酸及胺基酸序列比對結果發現,台灣所檢測之APV核酸序列VP1及T antigen coding region片段與基因庫所發表序列有較大之差異,其所轉譯之胺基酸變異有較多。而在PBFDV之ORF1轉譯之胺基酸序列則可見到一個replication motifs(YCKS)及一個nucleotide binding site motifs(GPPGCGKS),C1片段轉譯之胺基酸序列則具有4個高度變異之胺基酸。
Avian polyomavirus (APV) and psittacine beak and feather disease virus (PBFDV) are the common viral disease of psittacine birds. APV belongs to genes Avipolyomavirus of the family Papovaviridae, and causes acute fatal disease in young budgerigar with a mortality rate of up to 100%. APV infection is also known as budgerigar fledgling disease (BFD). PBFDV belongs to genes Circovirus of the family Circoviridae. PBFDV affects over 60 species of wild and captive psittacine birds. Clinical signs include chronic and progressive losses of feathers and in some species deformities of the beak and claws. In this study, polymerase chain reaction (PCR) was used to detect nucleic acids of APV and PBFDV for epidemical investigation. The results showed an APV positive rate of 28.8%, PBFDV positive rate of 55.1%, and mixed infections positive rate of 24.6%. By cloning and sequencing, sequences of the PCR products were compared with the sequence obtained from the GeneBank. In PBFDV sequences, the identity of VP1 genome and T antigen coding region genome sequences for Taiwan ranges 94.6-97.3% and 90.1-99.1%, respectively. In PBFDV sequences, the identity of ORF1 and C1 sequences ranges 87.5-97.3% and 86.5-98.4%, respectively. Base on nucleotide and amino acid sequencing analyses, there were variation in the VP1 genome and T antigen coding region genome sequences from that of the APV and samples from the GeneBank. Derived amino acid sequence alignment for PBFDV ORF1 fragments, demonstrates the replication motifs (YCKS) and the nucleotide binding site motif (GPPGCGKS). In PBFDV C1 amino acid sequence have four positions considered as hypervariable.