pH对拟态弧菌感染相关表型及胞外产物特性的影响

Effects of pH on Infection Phenotypes and Extracellular Products Properties of Vibrio mimicus

[目的]研究pH对拟态弧菌(Vibrio mimicus)感染相关表型及胞外产物特性的影响。[方法]测定不同pH(6.0、7.0、8.0、8.5和9.0)下拟态弧菌的增殖、泳动、自聚集和生物膜形成以及胞外产物(extracellular products,ECPs)的蛋白质量浓度、酶活性、溶血性、细胞毒性和毒力等特性。[结果]pH 6.0~9.0范围内,随着pH值升高,拟态弧菌的增殖先增强后减弱,pH 8.5时增殖最强;自聚集、生物膜形成和ECPs毒力先减弱后增强,pH 8.5时显著减弱(P<0.05);泳动以及ECPs蛋白质量浓度和细胞毒性减弱,pH 6.0时显著强于其他pH(P<0.05);ECPs酶活性和溶血性呈波动性,酶活性在pH 6.0时最强、pH 8.0时最弱,溶血性在pH 8.0时最强、pH 8.5时最弱。转录组分析显示:拟态弧菌pH 8.5较pH 7.0时,与ATP合成相关的糖酵解、TCA循环和氧化磷酸化等过程的基因表达上调,而与ADP合成相关的嘌呤合成基因、与蛋白质合成相关的核糖体亚基合成基因以及与蛋白分泌和膜运输相关的基因表达下调。[结论]pH对拟态弧菌感染相关表型及ECPs特性具有明显影响,且pH可能是通过调节拟态弧菌能量代谢与膜运输等过程影响其相关生物学特性。

[Purpose]To study the effect of pH on the phenotypes and extracellular products properties of Vibrio mimicus infection.[Methods]The proliferation,swimming motility,self-aggregation,biofilm formation,and the protein mass concentration,enzyme activity,hemolytic,cytotoxicity and virulence of extracellular products(ECPs)of V.mimicus were determined under different pH(6.0,7.0,8.0,8.5,9.0)conditions.[Results]At pH 6.0-9.0,with the increase of pH value,the prolifera-tion of V. mimicus increased first and then decreased with the strongest at pH 8.5;self-aggregation, biofilm formation and virulence of ECPs weakened first and then increased with the weakest power at pH 8.5 (P<0.05);swimming motility and protein mass concentration and cytotoxicity of ECPs showed a weakening trend, which pH 6.0 was significantly stronger than other pH value (P<0.05);in addition to the ECPs enzyme activities and hemolysis were fluctuated, which the strongest enzyme activity was at the pH 6.0 and the weakest enzyme activity at the pH 8.0;hemolytic was the strongest at pH 8.0 and the weakest at pH 8.5. Transcriptome analysis showed that: by comparing pH 7.0 and 8.5, the ex-pression of genes related to ATP synthesis such as glycolysis pathway, TCA cycle, and oxidative pho-sphorylation was up-regulated in pH 8.5, while the expression of genes related to ADP synthesis such as purine synthesis and ribosomal subunit synthesis was down-regulated. [Conclusion]pH has ob-vious influence on the V. mimicus infection-related phenotypes and ECPs characteristics, which may affect these related biological characteristics by regulating energy metabolism and membrane transport.