New aspects of RpoE in uropathogenic Proteus mirabilis

Ming Che Liu, Kuan Ting Kuo, Hsiung-Fei Chien, Yi Lin Tsai, Shwu Jen Liaw

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

Proteus mirabilis is a common human pathogen causing recurrent or persistent urinary tract infections (UTIs). The underlying mechanisms for P. mirabilis to establish UTIs are not fully elucidated. In this study, we showed that loss of the sigma factor E (RpoE), mediating extracytoplasmic stress responses, decreased fimbria expression, survival in macrophages, cell invasion, and colonization in mice but increased the interleukin-8 (IL-8) expression of urothelial cells and swarming motility. This is the first study to demonstrate that RpoE modulated expression of MR/P fimbriae by regulating mrpI, a gene encoding a recombinase controlling the orientation of MR/P fimbria promoter. By real-time reverse transcription-PCR, we found that the IL-8 mRNA amount of urothelial cells was induced significantly by lipopolysaccharides extracted from rpoE mutant but not from the wild type. These RpoE-associated virulence factors should be coordinately expressed to enhance the fitness of P. mirabilis in the host, including the avoidance of immune attacks. Accordingly, rpoE mutant-infected mice displayed more immune cell infiltration in bladders and kidneys during early stages of infection, and the rpoE mutant had a dramatically impaired ability of colonization. Moreover, it is noteworthy that urea (the major component in urine) and polymyxin B (a cationic antimicrobial peptide) can induce expression of rpoE by the reporter assay, suggesting that RpoE might be activated in the urinary tract. Altogether, our results indicate that RpoE is important in sensing environmental cues of the urinary tract and subsequently triggering the expression of virulence factors, which are associated with the fitness of P. mirabilis, to build up a UTI.

Original languageEnglish
Pages (from-to)966-977
Number of pages12
JournalInfection and Immunity
Volume83
Issue number3
DOIs
Publication statusPublished - 2015
Externally publishedYes

Fingerprint

Proteus mirabilis
Urinary Tract Infections
Virulence Factors
Urinary Tract
Interleukin-8
Antimicrobial Cationic Peptides
Polymyxin B
Recombinases
Aptitude
Reverse Transcription
Cell Movement
Cues
Lipopolysaccharides
Urea
Urinary Bladder
Macrophages
Urine
Kidney
Polymerase Chain Reaction
Messenger RNA

ASJC Scopus subject areas

  • Immunology
  • Microbiology
  • Parasitology
  • Infectious Diseases

Cite this

New aspects of RpoE in uropathogenic Proteus mirabilis. / Liu, Ming Che; Kuo, Kuan Ting; Chien, Hsiung-Fei; Tsai, Yi Lin; Liaw, Shwu Jen.

In: Infection and Immunity, Vol. 83, No. 3, 2015, p. 966-977.

Research output: Contribution to journalArticle

Liu, Ming Che ; Kuo, Kuan Ting ; Chien, Hsiung-Fei ; Tsai, Yi Lin ; Liaw, Shwu Jen. / New aspects of RpoE in uropathogenic Proteus mirabilis. In: Infection and Immunity. 2015 ; Vol. 83, No. 3. pp. 966-977.
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