scholarly journals Ynt is the primary nickel import system used by Proteus mirabilis and specifically contributes to fitness by supplying nickel for urease activity

2020 ◽  
Vol 114 (2) ◽  
pp. 185-199
Author(s):  
Aimee L. Brauer ◽  
Brian S. Learman ◽  
Chelsie E. Armbruster
Keyword(s):  
Proteus Mirabilis ◽  
Urease Activity ◽  
Import System

scholarly journals Deacidification by FhlA-dependent hydrogenase is involved in urease activity and urinary stone formation in uropathogenic Proteus mirabilis

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Wen-Yuan Lin ◽  
Shwu-Jen Liaw
Keyword(s):  
Proteus Mirabilis ◽  
Urease Activity ◽  
Stone Formation ◽  
Large Subunit ◽  
Acid Resistance ◽  
Urinary Stone ◽  
Potential Strategy ◽  
Ph Range ◽  
Tract Infections

Abstract Proteus mirabilis is an important uropathogen, featured with urinary stone formation. Formate hydrogenlyase (FHL), consisting of formate dehydrogenase H and hydrogenase for converting proton to hydrogen, has been implicated in virulence. In this study, we investigated the role of P. mirabilis FHL hydrogenase and the FHL activator, FhlA. fhlA and hyfG (encoding hydrogenase large subunit) displayed a defect in acid resistance. fhlA and hyfG mutants displayed a delay in medium deacidification compared to wild-type and ureC mutant failed to deacidify the medium. In addition, loss of fhlA or hyfG decreased urease activity in the pH range of 5–8. The reduction of urease activities in fhlA and hyfG mutants subsided gradually over the pH range and disappeared at pH 9. Furthermore, mutation of fhlA or hyfG resulted in a decrease in urinary stone formation in synthetic urine. These indicate fhlA- and hyf-mediated deacidification affected urease activity and stone formation. Finally, fhlA and hyfG mutants exhibited attenuated colonization in mice. Altogether, we found expression of fhlA and hyf confers medium deacidification via facilitating urease activity, thereby urinary stone formation and mouse colonization. The link of acid resistance to urease activity provides a potential strategy for counteracting urinary tract infections by P. mirabilis.

scholarly journals The Pathogenic Potential of Proteus mirabilis Is Enhanced by Other Uropathogens during Polymicrobial Urinary Tract Infection

2016 ◽  
Vol 85 (2) ◽  
Author(s):  
Chelsie E. Armbruster ◽  
Sara N. Smith ◽  
Alexandra O. Johnson ◽  
Valerie DeOrnellas ◽  
Kathryn A. Eaton ◽  
...  
Keyword(s):  
Urinary Tract Infection ◽  
Urinary Tract ◽  
Tract Infection ◽  
Disease Severity ◽  
Proteus Mirabilis ◽  
Tissue Damage ◽  
Urease Activity ◽  
Pathogenic Potential ◽  
Content Type

ABSTRACT Urinary catheter use is prevalent in health care settings, and polymicrobial colonization by urease-positive organisms, such as Proteus mirabilis and Providencia stuartii, commonly occurs with long-term catheterization. We previously demonstrated that coinfection with P. mirabilis and P. stuartii increased overall urease activity in vitro and disease severity in a model of urinary tract infection (UTI). In this study, we expanded these findings to a murine model of catheter-associated UTI (CAUTI), delineated the contribution of enhanced urease activity to coinfection pathogenesis, and screened for enhanced urease activity with other common CAUTI pathogens. In the UTI model, mice coinfected with the two species exhibited higher urine pH values, urolithiasis, bacteremia, and more pronounced tissue damage and inflammation compared to the findings for mice infected with a single species, despite having a similar bacterial burden within the urinary tract. The presence of P. stuartii, regardless of urease production by this organism, was sufficient to enhance P. mirabilis urease activity and increase disease severity, and enhanced urease activity was the predominant factor driving tissue damage and the dissemination of both organisms to the bloodstream during coinfection. These findings were largely recapitulated in the CAUTI model. Other uropathogens also enhanced P. mirabilis urease activity in vitro, including recent clinical isolates of Escherichia coli, Enterococcus faecalis, Klebsiella pneumoniae, and Pseudomonas aeruginosa. We therefore conclude that the underlying mechanism of enhanced urease activity may represent a widespread target for limiting the detrimental consequences of polymicrobial catheter colonization, particularly by P. mirabilis and other urease-positive bacteria.

Urease activity related to the growth and differentiation of swarmer cells of Proteus mirabilis

1987 ◽  
Vol 33 (4) ◽  
pp. 300-303 ◽  
Author(s):  
Tianru Jin ◽  
R. G. E. Murray
Keyword(s):  
Proteus Mirabilis ◽  
Urease Activity ◽  
Casein Hydrolysate ◽  
Brain Heart Infusion ◽  
Liquid Media ◽  
Whole Cells ◽  
Maximum Proportion ◽  
The Media ◽  
Urease Production ◽  
Different Strains

Urease activity was measured using whole cells of both long (swarming) and short (nonswarming) populations of Proteus mirabilis from casein hydrolysate agar (CHA) and broth (CHB) cultures, and from brain heart infusion broth (BHIB) cultures. Urease is a constitutive enzyme for both long and short cells, but its activity was tremendously increased when urea was incorporated into the media. Urease production was also affected by culture age and media used. Before exponential phase, urease activity was very low, and it increased to its highest point after about 4 h in BHIB and 8 h in both CHA and CHB cultures at 37 °C. Long cells had higher urease activity than did short cells when grown on CHA, and was also expressed by two different strains cultured in BHIB. Strain PM23, in BHIB, was able to form long cells (swarming cells) to a maximum proportion after about 4 h, but strain IM47 could not differentiate in any of the liquid media. The former had more urease when swarming differentiation was initiated. PM23 grew relatively faster than IM47 when the former began to differentiate, but this fast growth could not be observed when nutrient broth or minimal medium was used. These observations suggest that long or swarming cells are "faster growing" rather than "nongrowing bactera."

scholarly journals H-NS Is a Repressor of the Proteus mirabilis Urease Transcriptional Activator GeneureR

2000 ◽  
Vol 182 (9) ◽  
pp. 2649-2653 ◽  
Author(s):  
Christopher Coker ◽  
Olubunmi O. Bakare ◽  
Harry L. T. Mobley
Keyword(s):  
Nucleotide Sequence ◽  
Proteus Mirabilis ◽  
Binding Sites ◽  
Recombinant Plasmid ◽  
Urease Activity ◽  
Transcriptional Activator ◽  
Galactosidase Activity ◽  
Wild Type ◽  
Urease Gene ◽  
In Trans

ABSTRACT Expression of Proteus mirabilis urease is governed by UreR, an AraC-like positive transcriptional activator. A poly(A) tract nucleotide sequence, consisting of A6TA2CA2TGGTA5GA6TGA5, is located 16 bp upstream of the ς70-likeureR promoter P2. Since poly(A) tracts of DNA serve as binding sites for the gene repressor histone-like nucleoid structuring protein (H-NS), we measured β-galactosidase activity of wild-typeEscherichia coli MC4100 (H-NS+) and its isogenic derivative ATM121 (hns::Tn10) (H-NS−) harboring a ureR-lacZ operon fusion plasmid (pLC9801). β-Galactosidase activity in the H-NS− host strain was constitutive and sevenfold greater (P < 0.0001) than that in the H-NS+ host. A recombinant plasmid containing cloned P. mirabilis hns was able to complement and restore repression of the ureR promoter in the H-NS−host when provided in trans. Deletion of the poly(A) tract nucleotide sequence from pLC9801 resulted in an increase in β-galactosidase activity in the H-NS+ host to nearly the same levels as that observed for wild-type pLC9801 harbored by the H-NS−host. Urease activity in strains harboring the recombinant plasmid pMID1010 (encoding the entire urease gene cluster of P. mirabilis) was equivalent in both the H-NS−background and the H-NS+ background in the presence of urea but was eightfold greater (P = 0.0001) in the H-NS− background in the absence of urea. We conclude that H-NS represses ureR expression in the absence of urea induction.

scholarly journals UreR, the Transcriptional Activator of the Proteus mirabilis Urease Gene Cluster, Is Required for Urease Activity and Virulence in Experimental Urinary Tract Infections

2003 ◽  
Vol 71 (2) ◽  
pp. 1026-1030 ◽  
Author(s):  
Jonathan D. Dattelbaum ◽  
C. Virginia Lockatell ◽  
David E. Johnson ◽  
Harry L. T. Mobley
Keyword(s):  
Urinary Tract ◽  
Gene Cluster ◽  
Proteus Mirabilis ◽  
Urease Activity ◽  
Complicated Urinary Tract Infection ◽  
Wild Type ◽  
Urease Gene ◽  
Low Copy Number ◽  
Mutant Strains ◽  
Tract Infections

ABSTRACT Proteus mirabilis, a cause of complicated urinary tract infection, produces urease, an essential virulence factor for this species. UreR, a member of the AraC/XylS family of transcriptional regulators, positively activates expression of the ure gene cluster in the presence of urea. To specifically evaluate the contribution of UreR to urease activity and virulence in the urinary tract, a ureR mutation was introduced into P. mirabilis HI4320 by homologous recombination. The isogenic ureR::aphA mutant, deficient in UreR production, lacked measurable urease activity. Expression was not detected in the UreR-deficient strain by Western blotting with monoclonal antibodies raised against UreD. Urease activity and UreD expression were restored by complementation of the mutant strain with ureR expressed from a low-copy-number plasmid. Virulence was assessed by transurethral cochallenge of CBA mice with wild-type and mutant strains. The isogenic ureR::aphA mutant of HI4320 was outcompeted in the urine (P = 0.004), bladder (P = 0.016), and kidneys (P ≤ 0.001) 7 days after inoculation. Thus, UreR is required for basal urease activity in the absence of urea, for induction of urease by urea, and for virulence of P. mirabilis in the urinary tract.

Histochemical and biochemical urease localization in the periplasm and outer membrane of two Proteus mirabilis strains

1986 ◽  
Vol 32 (10) ◽  
pp. 772-778 ◽  
Author(s):  
Robert J. C. McLeanl ◽  
K.-J. Cheng ◽  
W. Douglas Gould ◽  
J. Curtis Nickel ◽  
J. William Costerton
Keyword(s):  
Outer Membrane ◽  
Proteus Mirabilis ◽  
Urease Activity ◽  
Enzymatic Reaction ◽  
Outer Membranes ◽  
Biochemical Measurements ◽  
Membrane Bound ◽  
Sodium Tetraphenylboron ◽  
Cell Fractions

Proteus mirabilis, a gram-negative bacillus, is often implicated in the formation of infections kidney stones. As ureolytic activity of this organism is thought to play a major role in its pathogenesis, we adapted our recently described urease localization technique to visualize urease activity in vivo. Urease activity was ultra structural] y localized in two clinically isolated P. mirabilis strains by precipitating the enzymatic reaction product (ammonia) with sodium tetraphenylboron. Subsequent silver staining of the cells revealed urease activity to be predominately associated with the periplasm and outer membranes of each strain. Biochemical measurements of urease activity in P. mirabilis cell fractions correlated well with histochemical observations in that the majority of urease activity was associated with the periplasm. Membrane-bound urease activity of these strains was associated mainly with the peptidoglycan in the detergent-insoluble (outer membrane) fraction.

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