Invasion of Aeromonas hydrophila strain Ah J-1 isolated from diseased fish to cultured HEp-2cells monolayer was evaluated by the recovery of gentamincin-resistant (Gm r)bacteria from Triton X-100 cell lysates. The inv...
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Invasion of Aeromonas hydrophila strain Ah J-1 isolated from diseased fish to cultured HEp-2cells monolayer was evaluated by the recovery of gentamincin-resistant (Gm r)bacteria from Triton X-100 cell lysates. The invasive efficiency (IE) could reach to 0.2% at 37℃. In addition, potential signal transduction pathways that precede bacterial internalization were studied by using signal transduction inhibitors. Bacterial internalization of Ah J-1 involved microfilaments and protein tyrosine kinase since cytochalasin D (an inhibitor of microfilament polymerization) and genistein (an inhibitor of protein tyrosine kinase) prevented internalization. Staurosporine(a protein kinase C inhibitor) and Sodium orthovanadate (a protein tyrosine phosphatase inhibitor) accelerated internalization of Ah J-1 into HEp-2 cells.
【目的】trag(transfer gene G)是利用IVIAT(in vivo induced antigen technology)通量筛选鉴定的猪链球菌2型(Streptococcus suis type 2,SS2)感染相关因子,研究该基因在猪链球菌(Streptococcus suis,SS)中的分布情况,研究康复血清与...
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【目的】trag(transfer gene G)是利用IVIAT(in vivo induced antigen technology)通量筛选鉴定的猪链球菌2型(Streptococcus suis type 2,SS2)感染相关因子,研究该基因在猪链球菌(Streptococcus suis,SS)中的分布情况,研究康复血清与免疫血清在免疫印迹中的反应性有无,间接证明其在体内感染与体外培养时表达差异。【方法】鉴于我国分离株trag与GenBank公布的SS2北美株89/1591的trag序列有95.8%的同源性,据此设计和合成一对检测引物,对SS2我国江苏及四川流行株、其他临床分离株和参考株及SS1、SS1/2、SS9、SS7及C群猪源链球菌共43株进行PCR扩增。另设计一对引物,扩增5株SS代表菌株trag的完整阅读框,并对扩增产物进行测序。据软件分析后,选择TRAG(Transfer protein G)免疫原性良好的区域片段的核酸设计表达引物,PCR扩增后定向克隆至表达载体pET28a(+)构建表达质粒,表达蛋白转印到PVDF膜上,分别与SS2猪康复血清和猪高免血清反应。【结果】trag在SS2中94%(30/32)阳性,SS9中67%(4/6)阳性,SS7阳性,SS1、SS1/2及C群菌阴性。5株细菌TRAG的氨基酸序列与SS2中国株98HAH33、05ZYH33及北美株89/1591同源性>97%。所获得重组蛋白只能被康复血清识别。【结论】从SS致病株中检出感染相关基因trag,提示该基因可能与SS致病性有关,重组蛋白的免疫转印结果表明,TRAG可能与SS2体内感染相关。
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