title: Involvement of polyphosphate kinase in virulence and stress tolerance of uropathogenic Proteus mirabilis.
abstract: 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.
authors.affiliation: Department of Clinical Laboratory, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510260, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Peng
authors.affiliation: Intensive Care Unit, Guangdong 999 Brain Hospital, Guangzhou, 510510, China.
authors.forename: Qiao
authors.initials: Q
authors.lastname: Jiang
authors.affiliation: Department of Clinical Laboratory, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510260, China.
authors.forename: Jia-Yun
authors.initials: JY
authors.lastname: Pan
authors.affiliation: Department of Clinical Laboratory, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510260, China.
authors.forename: Cong
authors.initials: C
authors.lastname: Deng
authors.affiliation: Department of Microbiology, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, 510515, China.
authors.forename: Jing-Yi
authors.initials: JY
authors.lastname: Yu
authors.affiliation: Department of Clinical Laboratory, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510260, China.
authors.forename: Xiao-Man
authors.initials: XM
authors.lastname: Wu
authors.affiliation: Department of Microbiology, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, 510515, China. shhuang@hsc.usc.edu.|Saban Research Institute, Childrens Hospital Los Angeles, Los Angeles, CA, 90027, USA. shhuang@hsc.usc.edu.
authors.forename: Sheng-He
authors.initials: SH
authors.lastname: Huang
authors.affiliation: Department of Clinical Laboratory, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510260, China. dxyzgy@163.com.
authors.forename: Xiao-Yan
authors.initials: XY
authors.lastname: Deng
mesh_terms: D000220:Adaptation, Biological / Q000235:genetics; D000818:Animals; D001422:Bacterial Adhesion / Q000235:genetics; D058491:Bacterial Load; D018441:Biofilms; D004195:Disease Models, Animal; D005260:Female; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D051379:Mice; D009154:Mutation; D017856:Phosphotransferases (Phosphate Group Acceptor) / Q000235:genetics / Q000378:metabolism*; D011512:Proteus Infections / Q000382:microbiology*; D011513:Proteus mirabilis / Q000502:physiology*; D013312:Stress, Physiological; D014552:Urinary Tract Infections / Q000382:microbiology; D014774:Virulence / Q000235:genetics; D037521:Virulence Factors / Q000235:genetics
chemical_list: D037521:Virulence Factors; D017856:Phosphotransferases (Phosphate Group Acceptor); C022424:polyphosphate kinase
keywords: Polyphosphate kinase; Proteus mirabilis; Urinary tract infection; Virulence