2株B型副鸡禽杆菌的分离鉴定

Isolation and Identification of Two Strains of Avibacterium paragallinarum Serovar B

2010年3月、2011年12月分别从北京平谷、延庆疑似鸡传染性鼻炎的病鸡体内各分离到1株细菌,根据发病鸡群的临床症状、细菌分离培养、形态观察、过氧化氢酶试验、革兰氏染色结合动物回归试验、免疫攻毒试验和PCR等方法初步鉴定为副鸡禽杆菌(Apg);同时将分离菌株送匈牙利诗华研发中心进行分型鉴定,确定为B型副鸡禽杆菌,根据分离地点将分离菌株命名为B型副鸡禽杆菌(平谷株和延庆株)。通过GenBank与已经发表的Apg基因序列进行同源性比对分析,结果显示,平谷株、延庆株基因序列同源性达到99.6%,而与参考株Modesto的基因核苷酸序列同源性达到98.3%、98.8%。

Two bacterial strains were separately isolated from the suspected disease chickens with infectious coryza in Pinggu （March of 2010） and Yanqing （December of 2011 ） district of Beijing. The isolates were initially identified as Avibacterium paragallinarum （Apg） based on the following methods： the clinical symptoms of the infected chicken, the isolation and the culture of bacterial strains, the morphological observation, catalase test, Gram stain combined with animal regression test, experimental challenge trial and PCR. The isolated bacterial strains were also sent to R＆D center of Ceva in Hungary for subtype identification, and the results confirmed that obtained bacterial was Apg （ serotype B） , which then named as serotype B Avibacterium paragallinarum, Pinggu strain and Yanqing strain, according to their isolated place. In addition, a 500 bp fragments of isolates was amplified and sequenced. These fragments were analyzed comparing with published HPG gene sequence. The results indicated that homology of nucleotide sequences of Pinggu and Yanqing strains reached 99. 6%. Meanwhile, the homology of nueleotide sequences of the isolated strains compared with the reference strain Modesto were 98.3 % and 98.8 % respectively.