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PubMed2003

An inducible tellurite-resistance operon in Proteus mirabilis.

Tellurite resistance (Te(r)) is widespread in nature and it is shown here that the natural resistance of Proteus mirabilis to tellurite is due to a chromosomally located orthologue of plasmid-borne ter genes found in enteric bacteria. The P. mirabilis ter locus (terZABCDE) was identified in a screen of Tn5lacZ-generated mutants of which one contained an insertion in terC. The P. mirabilis terC mutant displayed increased susceptibility to tellurite (Te(s)) and complementation with terC carried on a multicopy plasmid restored high-level Te(r). Primer extension analysis revealed a single transcriptional start site upstream of terZ, but only with RNA harvested from bacteria grown in the presence of tellurite. Northern blotting and reverse transcriptase-PCR (RT-PCR) analyses confirmed that the ter operon was inducible by tellurite and to a lesser extent by oxidative stress inducers such as hydrogen peroxide and methyl viologen (paraquat). Direct and inverted repeat sequences were identified in the ter promoter region as well as motifs upstream of the -35 hexamer that resembled OxyR-binding sequences. Finally, the 390 bp intergenic promoter region located between orf3 and terZ showed no DNA sequence identity with any other published ter sequences, whereas terZABCDE genes exhibited 73-85 % DNA sequence identity. The ter operon was present in all clinical isolates of P. mirabilis and Proteus vulgaris tested and is inferred for Morganella and Providencia spp. based on screening for high level Te(r) and preliminary PCR analysis. Thus, a chromosomally located inducible tellurite resistance operon appears to be a common feature of the genus Proteus.

Bacterial Proteins↗
PubMed2003

Differential regulation of the Proteus mirabilis urease gene cluster by UreR and H-NS.

Proteus mirabilis, a cause of catheter-associated urinary tract infection, relies on several virulence factors to colonize the urinary tract. Among these, urease contributes to the development of urinary stones resulting from the increase in local pH due to urease-mediated hydrolysis of urea to NH(3) and CO(2). UreR, an AraC-like transcriptional activator, activates transcription of the genes encoding the urease subunits and accessory proteins (ureDABCEFG) in the presence of urea. UreR also initiates transcription of its own gene in a urea-inducible manner by binding to the intergenic region between ureR and ureD. The intergenic region contains poly(A) tracts that appear to be the target of H-NS. It has been shown that Escherichia coli and P. mirabilis H-NS acts to repress transcription of ureR in an E. coli model system. It was hypothesized that H-NS represses urease gene expression in the absence of UreR and urea by binding to the intergenic region. To demonstrate this the P. mirabilis hns gene was cloned and the 15.6 kDa H-NS was overexpressed and purified as a myc-His tail fusion. Using a gel shift assay, purified H-NS-myc-His bound preferentially to a 609 bp DNA fragment containing the entire ureR-ureD intergenic region. H-NS and UreR were able to displace each other from the ureR-ureD intergenic region. Circular permutation analysis revealed that the intergenic region is bent. Moreover, H-NS recognizes this curvature, binds the DNA fragment and induces further bending of the DNA as shown by a circular ligation assay. The effects of H-NS, urea and temperature (25 vs 37 degrees C) on urease expression were shown in E. coli containing an hns knockout and P. mirabilis where expression was increased at 37 degrees C. Increased transcription from p(ureR) was seen in the E. coli hns knockout when temperature was increased from 25 to 37 degrees C. These findings suggest H-NS and UreR differentially regulate urease in a negative and positive manner, respectively.

Bacterial Proteins↗
PubMed2004

Enhanced motility of a Proteus mirabilis strain expressing hybrid FlaAB flagella.

Proteus mirabilis has two tandemly arranged flagellin-encoding genes, flaA and flaB. flaA is transcribed from a sigma(28) promoter, while flaB is silent. flaA and flaB can undergo reversible rearrangement to produce a set of hybrid genes referred to as flaAB. Flagellins composed of FlaAB protein have a different amino acid sequence and are antigenically distinct from flagellin composed of FlaA, implicating flagellin gene conversion as a putative virulence mechanism for P. mirabilis. The change in amino acid sequence is also hypothesized to alter the filament helix and, hence, affect the motility of FlaAB-expressing strains. To test this hypothesis, the motility of wild-type P. mirabilis was compared with that of a strain, DF1003, locked into the FlaAB(+) hybrid phase, under conditions of altered ionic strength, pH and viscosity. Cell motion tracking analysis showed that DF1003 has wild-type swimming velocity at physiological conditions, but moves significantly faster and travels further compared to the wild-type at NaCl concentrations greater than 170 mM. DF1003 is also significantly faster than the wild-type at pH 5.2, 5.8 and 8.2, and at 5 and 10 % polyvinylpyrrolidone. Measurements of amplitude and wavelength for isolated flagella subjected to pH 5.8 or 425 mM NaCl showed a loss of helical structure in FlaA flagella compared to FlaAB filaments, a feature that could significantly affect motility under these conditions. These results support a hypothesis that FlaAB flagellin imparts a motile advantage to P. mirabilis in conditions that otherwise may impede bacterial movement. In a broader context, flagellar antigenic variation, commonly thought to serve as means to avoid host defences, may also enhance motility in other bacterial species, thus aiding in the adaptation and survival of the cells.

Amino Acid Sequence↗
PubMed2006

Proteus mirabilis isolates of different origins do not show correlation with virulence attributes and can colonize the urinary tract of mice.

Proteus mirabilis has been described as an aetiological agent in a wide range of infections, playing an important role in urinary tract infections (UTIs). In this study, a collection of P. mirabilis isolates obtained from clinical and non-clinical sources was analysed in order to determine a possible correlation between origin, virulence factors and in vivo infectivity. Isolates were characterized in vitro, assessing several virulence properties that had been previously associated with P. mirabilis uropathogenicity. Swarming motility, urease production, growth in urine, outer-membrane protein patterns, ability to grow in the presence of different iron sources, haemolysin and haemagglutinin production, and the presence and expression of diverse fimbrial genes, were analysed. In order to evaluate the infectivity of the different isolates, the experimental ascending UTI model in mice was used. Additionally, the Dienes test and the enterobacterial repetitive intergenic consensus (ERIC)-PCR assay were performed to assess the genetic diversity of the isolates. The results of the present study did not show any correlation between distribution of the diverse potential urovirulence factors and isolate source. No significant correlation was observed between infectivity and the origin of the isolates, since they all similarly colonized the urinary tract of the challenged mice. Finally, all isolates showed unique ERIC-PCR patterns, indicating that the isolates were genetically diverse. The results obtained in this study suggest that the source of P. mirabilis strains cannot be correlated with pathogenic attributes, and that the distribution of virulence factors between isolates of different origins may correspond to the opportunistic nature of the organism.

Animals↗
PubMed2006

Observations on the adherence of Proteus mirabilis onto polymer surfaces.

AIMS: Infection of the catheterized urinary tract with Proteus mirabilis causes blockage of the catheter by crystalline bacterial biofilms. The aim of this work is to identify a surface-coating for catheters that is not vulnerable to colonization by Pr. mirabilis. METHODS AND RESULTS: A parallel-plate flow-cell and phase contrast microscopy were used to follow bacterial adhesion onto polymer films. Experiments with a urease-negative mutant of Pr. mirabilis suspended in buffer or urine, identified agarose as a polymer on which biofilm did not form. In tests with wild-type urease-producing cells in urine, no adhesion of cells onto agarose was observed for 3 h but then as the pH rose above 8.2, the surface rapidly became colonized by crystalline biofilm. CONCLUSIONS: In urine at pH below 8.0, Pr. mirabilis does not adhere to agarose-coated surfaces. When the pH rises above 8.2, however, aggregates of crystals and bacteria form in the urine and are deposited on such surfaces. SIGNIFICANCE AND IMPACT OF THE STUDY: Strategies to prevent the formation of crystalline biofilms on urinary catheters will need to consider both the properties of the surface-coatings and the requirement to prevent the alkaline conditions that induce crystal formation in urine.

Bacterial Adhesion↗
PubMed1988

Structural studies on the core and lipid A region of a 4-amino-L-arabinose-lacking Rc-type mutant of Proteus mirabilis.

The structure of the 4-amino-L-arabinose-lacking lipopolysaccharide of the Proteus mirabilis Rc-type mutant R4, derived from wild-type O28, was elucidated. The lipopolysaccharide core structure has previously been partially characterized. The linkage between heptose and deoxyoctulosonic acid(dOclA) is now reported, as well as the structure of the lipid A moiety of this mutant strain. Besides the tentative identification of an alpha-linked glucosamine disaccharide in the lipid A backbone accompanying the usual beta 1----6-linked glucosamine-disaccharide, the only significant structural variation to previous studies was the lack of substitution of the C-4' phosphate by 4-amino-L-arabinose. In addition, the substitution at C-8 of one dOclA unit by 4-amino-L-arabinose, previously reported for the R45 mutant of P. mirabilis 1959, is lacking in this R mutant. Also in addition to previous findings, the terminal unit of heptose was found to be substituted at C-7 with phosphorylethanolamine (PEtN) and not only with phosphate, although this substitution is not complete as demonstrated by the relevant signals in 31P-NMR. Additional studies with the wild-type strain P. mirabilis O28 revealed the presence of 4-amino-L-arabinose in both the core and the lipid A regions suggesting that the R4 mutant is defective in the biosynthesis of this amino sugar rather than in its transfer. Otherwise the lipid A regions of the mutant and the wild-type strain show no structural differences. The following formula is proposed for the lipopolysaccharide of 4-amino-L-arabinose-lacking mutant R4/O28 P. mirabilis: (Formula; see text)

Electrophoresis, Polyacrylamide Gel↗
PubMed1994

The single-stranded-DNA-binding proteins (SSB) of Proteus mirabilis and Serratia marcescens.

The single-stranded-DNA-binding (SSB) proteins from Proteus mirabilis and Serratia marcescens were purified from overproducing Escherichia coli strains, which were devoid of their own ssb gene. The strains harboured an endA insertion mutation and a xonA mutation resulting in the absence of endonuclease I and exonuclease I activities from the preparations. The amino acid sequences of the SSB of all three species are nearly identical in the N-terminal parts of the proteins that contain the DNA-binding domain, but differ in the C-terminal parts. Both proteins have an apparent binding-site size of 65 and 35 nucleotides at high and low salt concentrations, respectively. The association-rate constant for binding to poly(dT) is 3.2 x 10(8) M-1 s-1 for P. mirabilis SSB (PmiSSB) and 3.4 x 10(8) M-1 s-1 for S. marcescens SSB (SmaSSB). These binding parameters are very similar to those of E. coli SSB (EcoSSB). The structural similarity of the proteins is also documented by the finding that they can exchange subunits among each other to form mixed tetramers. The transcriptional regulation of the ssb and uvrA genes from P. mirabilis and S. marcescens in SOS-induced E. coli cells was studied using lacZ fusions. While the uvrA genes were inducible, there was no induction of the ssb genes transcribed divergently from the uvrA genes. Apparently, regions with nucleotide sequence similarity to the E. coli SOS-box preceding the ssb genes of P. mirabilis and S. marcescens had no gross effect on the transcription. Studies on growth of the cells and recovery from ultraviolet damage indicate that the heterologous SSB proteins support DNA replication and recombinational DNA repair of E. coli with the same efficiency as the E. coli SSB protein. Interactions with other E. coli proteins involved in these processes either do not occur, or are not impeded.

Amino Acid Sequence↗
PubMed1995

The structure and serological specificity of Proteus mirabilis O43 O antigen.

On the basis of sugar analysis and NMR spectroscopy, including selective spin-decoupling, one-dimensional NOE, two-dimensional homonuclear and 13C,1H-heteronuclear correlation spectroscopy, the following structure of the acidic O-specific polysaccharide of Proteus mirabilis O43 was established: -->4)-alpha-D-GalpA-(1-->3)-alpha-D-GalpA-(1-->3)-alpha-D-Gl cpNAc-(1-->4)-alpha - D-Glcp-(1-->, where GalA is galacturonic acid and Galp is galactopyranose. No serological cross-reactivity was observed between lipopolysaccharides of P. mirabilis O43 and other studied Proteus strains, except for P. mirabilis O10. The O-specific polysaccharide of P. mirabilis O43 was serologically active in precipitation and inhibition tests but the activity was lost after periodate oxidation. These data suggest that the O43 specificity is determined by a wide epitope with the immunodominant role of 4-substituted D-Glc or/and D-GalA, which are destroyed by periodate oxidation.

Antibodies, Bacterial↗
PubMed1996

Detection of Proteus mirabilis urease gene in urinary calculi by polymerase chain reaction.

BACKGROUND: Urea-splitting microorganisms cannot always be detected by stone or urine culture in patients with infection stones. Detection of genetic elements within the calculi by the polymerase chain reaction (PCR) may be a useful alternative. In this study, we assessed the usefulness of the PCR method in detecting the urease gene specific to Proteus mirabilis in urinary calculi. METHODS: Thirty-eight metabolic stones (calcium oxalate and/or calcium phosphate, uric acid, or cystine) and 49 struvite stones were examined. The PCR was applied with DNA extracted by boiling pulverized stone pieces. RESULTS: Of the 87 stones, PCR demonstrated the presence of the P. mirabilis urease elements ureC1 and ureC2 in 17, all of which were struvite. Stone culture and urine culture had been performed in 22 and 46 struvite stone cases, respectively, and the PCR was positive in all of the 10 culture-positive calculi and also in two calculi from which P. mirabilis was not isolated. CONCLUSION: PCR was reliable and convenient for detecting P. mirabilis in desiccated struvite calculi. Study to detect other species such as Ureaplasma or Corynebacterium would be useful in elucidating the role of bacterial infection in the formation of these stones.

Adult↗
PubMed2000

Virulence of a Proteus mirabilis ATF isogenic mutant is not impaired in a mouse model of ascending urinary tract infection.

Proteus mirabilis, a common cause of urinary tract infection, produces a number of different fimbriae, including ambient temperature fimbriae (ATF). These fimbriae are optimally expressed at 23 degrees C and their contribution to urinary tract infection has so far remained unknown. In the present study, a clinical isolate of P. mirabilis and an isogenic allelic replacement mutant unable to express ATF were tested for their ability to cause infection in the ascending urinary tract infection model in mice. The atf mutant colonised the urinary tract as well as the wild-type strain and was also able to outcompete the wild-type strain in a co-challenge experiment. Different non-clinical P. mirabilis isolates showed a reactive AtfA band after Western blot analysis using a polyclonal rabbit AtfA antiserum. These data together suggest that ATF does not play a role in P. mirabilis urinary tract infection.

Alleles↗
PubMed2001

New aspects of the role of MR/P fimbriae in Proteus mirabilis urinary tract infection.

Proteus mirabilis, a common cause of urinary tract infection (UTI), produces a number of different fimbriae including mannose-resistant Proteus-like fimbriae (MR/P). The precise role of different P. mirabilis fimbriae in ascending UTI has not yet been elucidated. In this study, a clinical isolate of P. mirabilis and an isogenic mutant unable to express MR/P were tested using different experimental approaches. They were tested for their ability to cause infection in an ascending co-infection model of UTI and in a haematogenous model in the mouse. In both models, the mutant was less able than the wild-type strain to colonise the lower and upper urinary tracts although infectivity was not abolished. In vitro adherence to uroepithelial cells was also assessed. Significant differences in adherence between both strains were observed at 1 h but not at 15 min post infection. We have also shown that a wild-type strain carries two copies of the mrpA gene. These data reinforce the importance of MR/P fimbriae in P. mirabilis UTI although other virulence factors may be necessary for efficient colonisation and development of infection.

Animals↗
PubMed2004

[Study of resistance mechanism on cefotaxime resistant Proteus mirabilis isolated from clinical specimens and its clinical background].

Over a 6-year period (1997 to 2002), 56 strains of Proteus mirabilis (12% of the total number of P. mirabilis isolates obtained) resistant to ampicillin, piperacillin, cefazolin and cefoperazone by routine antimicrobial testing method, were isolated in Saitama Medical School Hospital. Of the 56 strains resistant to 4 beta-lactams, 12 strains were studied and were found to produce extended-spectrum beta-lactamases, identified as CTX-M-10 group and Toho-1 group in 8 and 2 strains, respectively. Susceptibility testing showed that 12 strains were resistant to cefotaxime, and cepodoxime, and ceftriaxon but susceptible to ceftazidime. Moreover, all of the beta-lactamases were inhibited by clavulanic acid. Of the 12 strains, one strain showed resistance to cephamycins such as cefoxitin, cefmetazole and cefotetan. Four of the twelve patients had infections caused by ESBL producing P. mirabilis, and eight patients were colonized, as confirmed by clinical and laboratory findings. The infections were urinary tract infections (two episodes), pneumonia (one episode), and sepsis (one episode). These patients had a favorable response to antibiotic therapy including cephalosporin. From these findings, CTX-M-type beta-lactamase producing P. mirabilis strains were confirmed from clinical specimens in our hospital.

Cefotaxime↗
PubMed2001

Identification of Proteus mirabilis mutants with increased sensitivity to antimicrobial peptides.

Antimicrobial peptides (APs) are important components of the innate defenses of animals, plants, and microorganisms. However, some bacterial pathogens are resistant to the action of APs. For example, Proteus mirabilis is highly resistant to the action of APs, such as polymyxin B (PM), protegrin, and the synthetic protegrin analog IB-367. To better understand this resistance, a transposon mutagenesis approach was used to generate P. mirabilis mutants sensitive to APs. Four unique PM-sensitive mutants of P. mirabilis were identified (these mutants were >2 to >128 times more sensitive than the wild type). Two of these mutants were also sensitive to IB-367 (16 and 128 times more sensitive than the wild type). Lipopolysaccharide (LPS) profiles of the PM- and protegrin-sensitive mutants demonstrated marked differences in both the lipid A and O-antigen regions, while the PM-sensitive mutants appeared to have alterations of either lipid A or O antigen. Matrix-assisted laser desorption ionization-time of flight mass spectrometry analysis of the wild-type and PM-sensitive mutant lipid A showed species with one or two aminoarabinose groups, while lipid A from the PM- and protegrin-sensitive mutants was devoid of aminoarabinose. When the mutants were streaked on an agar-containing medium, the swarming motility of the PM- and protegrin-sensitive mutants was completely inhibited and the swarming motility of the mutants sensitive to only PM was markedly decreased. DNA sequence analysis of the mutagenized loci revealed similarities to an O-acetyltransferase (PM and protegrin sensitive) and ATP synthase and sap loci (PM sensitive). These data further support the role of LPS modifications as an elaborate mechanism in the resistance of certain bacterial species to APs and suggest that LPS surface charge alterations may play a role in P. mirabilis swarming motility.

Amino Acid Sequence↗
PubMed2004

Four variants of the Citrobacter freundii AmpC-Type cephalosporinases, including novel enzymes CMY-14 and CMY-15, in a Proteus mirabilis clone widespread in Poland.

Twenty-nine Proteus mirabilis isolates from 17 Polish hospitals were analyzed. The isolates were resistant to a variety of antimicrobials, and their patterns of resistance to beta-lactams resembled those of the constitutive class C cephalosporinase (AmpC) producers. Indeed, beta-lactamases with a pI of approximately 9.0 were found in all of the isolates, and they were subsequently identified as four AmpC-type cephalosporinases, CMY-4, -12, -14, and -15, of which the two last ones were novel enzyme variants. The enzymes were of Citrobacter freundii origin and were closely related to each other, with CMY-4 likely being the evolutionary precursor of the remaining ones. The bla(CMY) genes were located exclusively in chromosomal DNA, within EcoRI restriction fragments of the same size of approximately 10 kb. In the CMY-12- and -15-producing isolates, an additional fragment of approximately 4.5 kb hybridized with the bla(CMY) probe as well, which could have arisen from a duplication event during the evolution of the genes. In all of the isolates, the ISEcp1 mobile element, which most probably is involved in mobilization of the C. freundii ampC gene, was placed at the same distance from the 5' ends of the bla(CMY) genes, and sequences located between them were identical in isolates carrying each of the four genes. These data suggested that a single chromosome-to-chromosome transfer of the ampC gene from C. freundii to P. mirabilis could have initiated the spread and evolution of the AmpC-producing P. mirabilis in Poland. The hypothesis seems to be confirmed by pulsed-field gel electrophoresis typing, which revealed several cases of close relatedness between the P. mirabilis isolates from distant centers and showed an overall similarity between the majority of the multiresistant isolates.

Amino Acid Sequence↗
PubMed1980

Immunological characterization of two major proteins isolated from the outer membrane of Proteus mirabilis.

Two proteins with apparent molecular weights of 39,000 and 36,000 (M(r) 39,000 and M(r) 36,000, respectively) were isolated from the outer membrane of Proteus mirabilis 19. M(r) 36,000 was shown to be free of detectable amounts of the M(r) 39,000 protein by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and free of lipopolysaccharide according to gas chromatographic analyses of 3-hydroxymyristic acid content. The M(r) 39,000 protein contained no detectable amount of lipopolysaccharide and only a trace of M(r) 36,000. Both isolated proteins gave strong reactions in antisera produced to purified P. mirabilis 19 cell walls (outer membrane proteins in the native state). This suggested that the proteins isolated by our methods essentially retained their native configuration upon resolubilization. Antisera produced in rabbits to the isolated proteins showed strongest reactions with the homologous antigen, but some cross-reactions with the heterologous protein and with P. mirabilis 19 lipopolysaccharide were observed. These cross-reactions could be attributed to specific responses to traces of the heterologous (contaminant) proteins present in the purified proteins used as immunizing antigens. The M(r) 39,000 and M(r) 36,000 proteins have no major antigenic determinants in common. Reactions with P. mirabilis 19 lipopolysaccharide in antisera to the outer membrane proteins could be completely removed by absorption of the antisera with the M(r) 36,000 protein.

Antigens, Bacterial↗
PubMed1984

Vero cell invasiveness of Proteus mirabilis.

Vero cell invasiveness was studied for a group of Proteus mirabilis strains isolated from the urinary tract and feces and for a limited group of urinary isolates of Escherichia coli. Experimental conditions affecting this invasiveness were studied. All of the P. mirabilis strains tested were capable of cell invasion, whereas none of the E. coli strains was. Correlation between the hemolytic activity of the P. mirabilis strains and their invasive ability suggested that the bacterial hemolysin may be involved in the invasion process. Other experimental evidence supporting this hypothesis is discussed. The differences in the invasive capacities of P. mirabilis and of E. coli may be important for the apparent differences in the pathogenesis of urinary tract infection by both species.

Animals↗
PubMed1990

Tissue-binding affinity of Proteus mirabilis fimbriae in the human urinary tract.

Binding characteristics of the two major fimbrial hemagglutinin types of uropathogenic Proteus mirabilis were determined in frozen sections of human kidney and in exfoliated uroepithelial cells. P. mirabilis 3087, which expresses the MR/P fimbriae, adhered avidly to the tubular epithelial cells of the kidney and also to the epithelial cells of urinary sediment. No adhesion to glomerular or peritubular elements of the kidney was detected. Indirect immunogold silver staining also showed that the purified MR/P fimbriae recognized the same kidney domains. Adhesion of strain 3087 to uroepithelial cells was completely inhibited by Fab fragments of antibodies against the purified MR/P fimbriae. A completely different tissue-binding pattern was exhibited by the MR/K fimbriae of P. mirabilis 2456. In the kidney, the MR/K fimbriae bound strongly to the Bowman's capsule of the glomeruli and to the tubular basement membranes. A weak binding to glomerular mesangium and tubular epithelial cells was also seen. Strain 2456 did not adhere to epithelial cells of urinary sediment. Analysis of normal human urine showed that it contains low-molecular-weight molecules capable of inhibiting the binding of the MR/P fimbriae; no urinary inhibitors could be detected for the MR/K fimbriae. Poor in vivo binding capacity to intact human uroepithelial cells may be an important factor in explaining the relatively low pathogenicity of P. mirabilis in healthy hosts.

Bacterial Adhesion↗
PubMed1990

Construction of a urease-negative mutant of Proteus mirabilis: analysis of virulence in a mouse model of ascending urinary tract infection.

Proteus mirabilis, a urease-producing uropathogen, causes serious urinary tract infections in humans. To specifically evaluate the contribution of urease to virulence, a mutation was introduced into P. mirabilis HI4320 by homologous recombination. Virulence was assessed in the CBA mouse model of ascending urinary tract infection. Twenty mice each were challenged transurethrally with P. mirabilis HI4320 and its urease-negative derivative (1 x 10(9) to 2 x 10(9) CFU). At 48 h animals were sacrificed and the mean log10 CFU per milliliter of urine (parent, 6.23; mutant, 4.19; P = 0.0014) or per gram of bladder (parent, 6.29; mutant, 4.28; P = 0.0002), left kidney (parent, 4.11; mutant, 1.02; P = 0.00009), and right kidney (parent, 4.11; mutant, 2.43; P = 0.036) were all shown to be significantly different. These data demonstrate a role for urease as a critical virulence determinant for uropathogenic P. mirabilis.

Animals↗