Involvement of polyphosphate kinase in virulence and stress tolerance of uropathogenic Proteus mirabilis.
Involvement of polyphosphate kinase in virulence and stress tolerance of uropathogenic Proteus mirabilis.
复制标题
多磷酸激酶参与尿路致病性奇异变形杆菌的毒力和应激耐受性。
DOI：
10.1007/s00430-015-0430-1
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发表时间：
2016-04
影响因子：
5.4
通讯作者：
Deng XY
中科院分区：
文献类型：
--
作者：
Peng L;Jiang Q;Pan JY;Deng C;Yu JY;Wu XM;Huang SH;Deng XY
奇异变形杆菌(Proteus mirabilis，P.mirabilis)是一种革兰氏阴性肠道细菌，常引起尿路感染。目前已鉴定出多种致尿性奇异肺炎杆菌的毒力因子，包括尿素酶、鞭毛、溶血素和菌毛。然而，在奇异假单胞菌中，与许多细菌致病相关的多聚磷酸酶(PPK)的功能仍然完全未知。本研究构建了编码奇异P.mirabilis菌株HI4320中PPK插入突变体的PPK基因，并对其生物学功能进行了研究。存活研究结果表明，突变体PPK缺乏对氧化、高渗和热胁迫的抗性。中断PPK后，奇异P.mirabilis的聚集性和生物膜形成能力也减弱。体外和体内实验表明，奇异巴氏杆菌侵入膀胱需要PPK。PPK突变体的阴性表型可通过PPK基因互补恢复。利用双向凝胶电泳法和液质联用技术对野生型菌株和突变型PPK菌株的蛋白质组进行了分析。与野生型相比，TonB依赖受体、通用应激蛋白G、主要的甘露糖抗性/类变形菌毛蛋白(MR/P菌毛)、热休克蛋白、鞭毛封盖蛋白、膜蛋白和多药外排蛋白等7种蛋白表达下调，出口肽酶、FTSI阻遏蛋白、FKBP型肽-脯氨基顺式反式异构酶和磷酸转移酶等4种蛋白表达上调。综上所述，这些结果表明PPK是一种重要的调节因子，在泌尿系致病P.mirabilis的抗逆性和毒力中起着至关重要的作用。
Proteus mirabilis (P. mirabilis), a gram-negative enteric bacterium, frequently causes urinary tract infections. Many virulence factors of uropathogenic P. mirabilis have been identified, including urease, flagella, hemolysin and fimbriae. However, the functions of polyphosphate kinase (PPK), which are related to the pathogenicity of many bacteria, remain entirely unknown in P. mirabilis. In this study, a ppk gene encoding the PPK insertional mutant in P. mirabilis strain HI4320 was constructed, and its biological functions were examined. The results of survival studies demonstrated that the ppk mutant was deficient in resistance to oxidative, hyperosmotic and heat stress. The swarming and biofilm formation abilities of P. mirabilis were also attenuated after the ppk interruption. In vitro and in vivo experiments suggested that ppk was required for P. mirabilis to invade the bladder. The negative phenotypes of the ppk mutant could be restored by ppk gene complementation. Furthermore, two-dimensional gel electrophoresis and liquid chromatography–mass spectrometry were used to analyze the proteomes of the wild-type strain and the ppk mutant. Compared with the wild-type strain, seven proteins including TonB-dependent receptor, universal stress protein G, major mannose-resistant/Proteus-like fimbrial protein (MR/P fimbriae), heat shock protein, flagellar capping protein, putative membrane protein and multidrug efflux protein were down-regulated, and four proteins including exported peptidase, repressor protein for FtsI, FKBP-type peptidyl-prolyl cis–trans isomerase and phosphotransferase were up-regulated in the ppk mutant. As a whole, these results indicate that PPK is an important regulator and plays a crucial role in stress tolerance and virulence in uropathogenic P. mirabilis.