| 摘要: |
| 【目的】了解当前支气管败血波氏杆菌(Bb)地方菌株皮肤坏死毒素（DNT）基因的变异特点。【方法】利用分离培养、PCR及16S rRNA扩增片段同源性分析，对采自四川遂宁某规模化猪场有明显萎缩性鼻炎症状的鼻拭子进行病原分离鉴定，并对分离株的DNT基因进行克隆和序列分析，对其抗原域、氨基酸二级结构、特定区域位于蛋白质表面可能性等参数进行预测，分析其B细胞抗原表位。【结果】成功分离得到一株支气管败血波氏杆菌，命名为支气管败血波氏杆菌SC-SN株。分离株DNT基因序列全长4 357 bp，与其他11株菌DNT基因的核苷酸序列同源性为93.1%～100.0%，但由于其356位插入碱基A，使得该序列仅编码1 426个氨基酸，与上述11株DNT基因编码的氨基酸序列同源性仅为12.8%～47.0%。遗传进化树显示，SC-SN 分离株与S798日本株和未知1株的亲缘关系最近。软件预测结果显示，Bb SC-SN株DNT基因编码氨基酸B细胞抗原表位发生较大变化。【结论】经鉴定，分离株确为支气管败血波氏杆菌，且SC-SN株的DNT基因序列变异较大，第356位插入的碱基A，对其氨基酸序列、ORF及B细胞抗原表位分布产生了较大的影响。 |
| 关键词: 支气管败血波氏杆菌 分离鉴定 皮肤坏死毒素基因 猪 |
| DOI： |
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| 基金项目:国家“十二五”科技支撑计划项目（2013BAD12B04） |
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| Identification of an Bb SC-SN isolated from Sichuan and sequence analysis of DNT gene |
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XIAO Lu,WU Xulong,WANG Yin,et al
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| Abstract: |
| 【Objective】This study investigated the variation characteristics of Bordetella bronchiseptica DNT gene in Sichuan.【Method】A Bordetella bronchiseptica strain was identified from swine nose swab with respiratory disease from a pig farm in Suining,Sichuan by cultivation,PCR and 16S rRNA homology analysis.Then,DNT of the strain was cloned,the sequence,antigenicity,amino acid secondary structure,certain location surface accessibility in protein and B cell epitopes were analyzed.【Result】A Bordetella bronchiseptica strain was separated successfully and named Bb SC-SN.The sequence analysis showed that the length of DNT was 4 357 bp,and it coded 1 426 amino acids with A inserted in the 356th position.The DNT sequence of SC-SN strain shared 93.1%－100.0% homology with other 11 strains,but the homology of amino acid sequences was 12.8%－47.0%.Phylogenetic tree showed that DNT of SC-SN strain had closest relationship to S798.The B cell epitopes of Bb SC-SN DNT amino acid changed greatly according to model prediction.【Conclusion】The isolated SC SN strain was Bordetella bronchiseptica,and its DNT varied greatly.The base A at the 356th position had great influence on amino acids,ORFs and B cell epitopes. |
| Key words: Bordetella bronchiseptica identification DNT swine |
