摘要： 为了解猪肺炎支原体流行菌株遗传变异情况，选取2014-2017年不同时间、地点收集的17头猪肺炎支原体阳性屠宰猪肺脏灌洗液DNA为模板，进行猪肺炎支原体P36（编码具有强免疫原性的胞浆蛋白）、P46（编码具有强免疫原性的表面蛋白）、P97 R1区、P146高变区（猪肺炎支原体黏附气管纤毛细胞的重要功能区域）基因的PCR扩增、测序。结合GenBank登录的猪肺炎支原体相关序列进行氨基酸序列的比对分析。结果表明，比对的序列之间，P36、P46蛋白氨基酸序列同源性均在98.9%以上，但P97功能区R1区、P146多变区在菌株间存在较大差异。11个屠宰猪样本和5个GenBank登录菌株P97 R1区重复氨基酸序列数量达到14个以上，而GenBank登录的3个疫苗相关菌株（168株、168-L株、J株）及另外4个菌株、4个屠宰猪样本重复序列为9~11个不等；P146高变区氨基酸序列的差异主要集中在2个重复氨基酸序列区（R1、R2），GenBank登录的168株、168-L株、J株以及另外2个菌株，1个屠宰猪样本在R1区出现较多氨基酸缺失。168株、168-L株，6个屠宰猪样本及另外3个GenBank登录菌株在R2区出现了3~9个不等的氨基酸缺失。利用DNAStar进行抗原表位预测发现，菌株间P97 R1、P146 R1、P146 R2区氨基酸序列的差异，导致了抗原表位出现明显的变化。提示开展P97、P146等黏附因子的筛选和研究或许能进一步提升疫苗阻止猪肺炎支原体黏附气管纤毛细胞的作用，从而进一步改善疫苗的免疫效果。

关键词: 猪肺炎支原体, P36, P46, P97, P146, PCR, 差异分析

Abstract: To understand the genetic variation of Mycoplasma hyopneumoniae (M.hyo) epidemic strain, a conventional PCR was employed to amplify the fragments of M. hyo P36, P46, P97 R1 and P146 gene from the DNA mix of bronchoalveolar lavage fluid of 17 slaugher pigs, which had been tested positive to M.hyo, and the PCR products were sequenced directly and analyzed. The deduced amino acid sequences of P36 and P46 were conservative between M.hyo of 17 slagughter pig lung samples and those strains registered in GenBank, with a homology of more than 98.9%. Among the amino acid sequences, there were large variations in P97 R1 area and 2 repetitive sequence regions (R1, R2) of P146. P97 amino acid sequences R1 area of M.hyo from 11 slaughter pig samples and 5 strains registered in GenBank were composed of 14 or more tandem copies. It was composed of 9-11 tandem copies in three vaccine-related strains(168 strain, 168-L strain, J strain), four other strains registered in GenBank, and 4 strains from slaughter pigs. A few amino acid deficiency was observed in R1 area of P146 from 5 strains registered in GenBank (168 strain, 168-L strain, J strain, and two other strains) and 1 slaughter pig samples, and 3-9 amino acid deficiency was observed in R2 area of P146 from 11 strains (168-L strain, 168 strain, three other strains registered in GenBank, and 6 strains detected from slaughter pig). Consequently, antigen epitope prediction showed significant difference in P97 R1 area and two repetitive sequence regions (R1, R2) of P146. To the best of our knowledge, this study was the first preliminary investigation to M.hyo strain in slaughter pigs in Hunan province, and it could provide some significant data for understanding the prevalence of M.hyo strain in different areas and screening of vaccine candidate strains.

Key words: Mycoplasma hyopneumoniae, P36, P46, P97, P146, PCR, Difference analysis

中图分类号: 

• S852.62