猪附红细胞体病原特征及其致病性分析

Study on characteristics and pathogenicity of Mycoplasma suis

为研究猪附红细胞体的病原形态学特征及其致病特性,给6只临床健康小鼠成功感染了猪附红细胞体病,对试验组小鼠感染后的不同时期采集的血样进行了鲜血压片、姬姆萨染色及扫描电子显微镜下的形态学检查,红细胞计数和以P1:5′-GCATGCCCAGTCCCCAAGGA-3′和P2:5′-TGCGGGGAGTACGTGGGAAGG-3′为特异性引物,利用2003年LudwigE报道的方法对待检血样中附红细胞体DNA的PCR鉴定及测序。1000倍油镜下观察到单个或连成线状的附红细胞体附着于红细胞表面,红细胞变成刺状、菠萝状或"口"字形等不规则形状;12000倍扫描电镜下观察到了"逗点"状及以纤丝与红细胞膜相连的附红细胞体;红细胞计数结果显示:与对照组相比试验组小鼠在接种后第7、10、14天出现大量异型性红细胞,其中第10天严重变形红细胞数量最多。说明猪附红细胞体病发病明显期在感染后第7～14天,14d以后逐渐消散;PCR扩增得到782bp的DNA片段,经序列分析与序列号为AJ504999的相应片段同源性为99.74%。本试验为猪附红细胞体的病原特性的研究提供了科学依据,为猪附红细胞体病发病机理等方面更深入的研究奠定了基础。

To excogitate the morphologic characteristics and pathogenicity of Mycoplasma suis,on 6experimental mice were induced with porcine eperythrozoonosis and were blood samples collected at the different time points. Blood tabletting and Giemsa staining,electron microscopic study and blood cell counting were all performed.PCR analysis was also performed according to the method of Ludwig E.Hoelzle for the gene of M.suis.The upper primer was P1 （5′-GCATGCCCAGTCCCCAAGGA-3′）and the lower primer was P2 （5′-TGCGGGGAGTACGTGG- GAAGG-3′）.Light microscopy examination showed some M.suis existed singly or lined in line and lots of anamor-phic erythrocytes.Scanning electron microscopy examination revealed some near-round M.suis appearing as a＂comma＂and some M.suis sticked onto the plasmalemma of the disintegrated erythrocyte via fibril.Blood cell counting showed many anamorphic erythrocytes at day 7,10and 14post-inoculation,and serious normocytes are in majority at day 10post-inoculation.The results suggested that porcine eperythrozoonosis is most serious at the time of 7-14days post-inoculation.PCR analysis showed the presence of a 782bp DNA fragment,which was 99.74% of homology with the parallel DNA sequences of#AJ504999.This study provided constructive argument for the study of eperythrozoonosis,and laid the foundation of further research on pathogensis.