用流式细胞术分析耐药质粒与伤寒沙门菌在巨噬细胞内生存的关系

Analysis of the relationship between S.typhi R plasmid and the strains survival within macrophages by flow cytometry

目的用流式细胞术分析伤寒沙门菌不相容性 C群可接合性耐药质粒 p RST98与其宿主菌在巨噬细胞内生存的关系。方法荧光染料标记 3株染色体同源的伤寒沙门菌 -含 p RST98野生型伤寒沙门菌株 STp RST98、人工消除 p RST98的突变体菌株 ST( R- ) 及将 p RST98再重新导入突变体的接合子菌株 p RST98/ ST( R- ) ,用流式细胞仪检测它们被 BAL B/ c小鼠腹腔巨噬细胞 MФ J774A.1 吞噬和吞噬后在细胞内的存活情况。结果被巨噬细胞吞噬的标记 ST( R- )菌量显著多于 STp RST98和 p RST98/ ST( R- ) (t检验 ,P<0 .0 5 ) ,但 p RST98宿主菌在巨噬细胞内的活菌数却明显高于无此质粒的菌株 (t检验 ,P<0 .0 5 )。结论 p RST98不但能编码对药物的抗性 。

Objective The research deals with whether the conjugation IncC group R plasmid (pR ST98 )could contribute to the host bacteria survival within macrophages. methods Three chromosomal isogenic strains,i.e.,plasmid containing wide type S.typhi strain STpR ST98 ,plasmid artificially cured strain ST (R -) and plasmid reintroduced into the cured strain pR ST98 /ST (R -) were fluorescence labeled and compared for their ability to survival within BALB/c mouse macrophage cell MΦJ 774A.1 by flow cytometry. Results More ST (R -) strains were phagocytosed by macrophages than STpR ST98 and pR ST98 /ST (R -) ,but the numbers of viable bacteria of STpR ST98 and pR ST98 /ST (R -) were higher than that of ST (R -) . Conclusion pR ST98 not only could mediate drug resistance,but also resist to the phagocytosis and enhance intracellular growth of S.typhi in macrophages.