scholarly journals Proteus mirabilis Genes That Contribute to Pathogenesis of Urinary Tract Infection: Identification of 25 Signature-Tagged Mutants Attenuated at Least 100-Fold

2004 ◽  
Vol 72 (5) ◽  
pp. 2922-2938 ◽  
Author(s):  
Laurel S. Burall ◽  
Janette M. Harro ◽  
Xin Li ◽  
C.Virginia Lockatell ◽  
Stephanie D. Himpsl ◽  
...  
Keyword(s):  
Urinary Tract ◽  
Mouse Model ◽  
Virulence Factors ◽  
Proteus Mirabilis ◽  
Parent Strain ◽  
Iron Acquisition ◽  
Phosphate Transport ◽  
Transposon Mutants ◽  
Cell Surface Structure ◽  
Tract Infections

ABSTRACT Proteus mirabilis, a common cause of urinary tract infections (UTI) in individuals with functional or structural abnormalities or with long-term catheterization, forms bladder and kidney stones as a consequence of urease-mediated urea hydrolysis. Known virulence factors, besides urease, are hemolysin, fimbriae, metalloproteases, and flagella. In this study we utilized the CBA mouse model of ascending UTI to evaluate the colonization of mutants of P. mirabilis HI4320 that were generated by signature-tagged mutagenesis. By performing primary screening of 2,088 P. mirabilis transposon mutants, we identified 502 mutants that ranged from slightly attenuated to unrecoverable. Secondary screening of these mutants revealed that 114 transposon mutants were reproducibly attenuated. Cochallenge of 84 of these single mutants with the parent strain in the mouse model resulted in identification of 37 consistently out-competed P. mirabilis transposon mutants, 25 of which were out-competed >100-fold for colonization of the bladder and/or kidneys by the parent strain. We determined the sequence flanking the site of transposon insertion in 29 attenuated mutants and identified genes affecting motility, iron acquisition, transcriptional regulation, phosphate transport, urease activity, cell surface structure, and key metabolic pathways as requirements for P. mirabilis infection of the urinary tract. Two mutations localized to a ∼42-kb plasmid present in the parent strain, suggesting that the plasmid is important for colonization. Isolation of disrupted genes encoding proteins with homologies to known bacterial virulence factors, especially the urease accessory protein UreF and the disulfide formation protein DsbA, showed that the CBA mouse model and mutant pools are a reliable source of attenuated mutants with mutations in virulence genes.

scholarly journals Identification of virulence determinants in uropathogenic Proteus mirabilis using signature-tagged mutagenesis

2008 ◽  
Vol 57 (9) ◽  
pp. 1068-1078 ◽  
Author(s):  
Stephanie D. Himpsl ◽  
C. Virginia Lockatell ◽  
J. Richard Hebel ◽  
David E. Johnson ◽  
Harry L. T. Mobley
Keyword(s):  
Urinary Tract ◽  
Mouse Model ◽  
Proteus Mirabilis ◽  
Virulence Determinants ◽  
Indwelling Catheters ◽  
Cba Mice ◽  
Transposon Mutants ◽  
Tract Infections

The Gram-negative bacterium Proteus mirabilis causes urinary tract infections (UTIs) in individuals with long-term indwelling catheters or those with functional or structural abnormalities of the urinary tract. Known virulence factors include urease, haemolysin, fimbriae, flagella, DsbA, a phosphate transporter and genes involved in cell-wall synthesis and metabolism, many of which have been identified using the technique of signature-tagged mutagenesis (STM). To identify additional virulence determinants and to increase the theoretical coverage of the genome, this study generated and assessed 1880 P. mirabilis strain HI4320 mutants using this method. Mutants with disruptions in genes vital for colonization of the CBA mouse model of ascending UTI were identified after performing primary and secondary in vivo screens in approximately 315 CBA mice, primary and secondary in vitro screens in both Luria broth and minimal A medium to eliminate mutants with minor growth deficiencies, and co-challenge competition experiments in approximately 500 CBA mice. After completion of in vivo screening, a total of 217 transposon mutants were attenuated in the CBA mouse model of ascending UTI. Following in vitro screening, this number was reduced to 196 transposon mutants with a probable role in virulence. Co-challenge competition experiments confirmed significant attenuation for 37 of the 93 transposon mutants tested, being outcompeted by wild-type HI4320. Following sequence analysis of the 37 mutants, transposon insertions were identified in genes including the peptidyl-prolyl isomerases surA and ppiA, glycosyltransferase cpsF, biopolymer transport protein exbD, transcriptional regulator nhaR, one putative fimbrial protein, flagellar M-ring protein fliF and hook protein flgE, and multiple metabolic genes.

scholarly journals New Aspects of RpoE in Uropathogenic Proteus mirabilis

2014 ◽  
Vol 83 (3) ◽  
pp. 966-977 ◽  
Author(s):  
Ming-Che Liu ◽  
Kuan-Ting Kuo ◽  
Hsiung-Fei Chien ◽  
Yi-Lin Tsai ◽  
Shwu-Jen Liaw
Keyword(s):  
Urinary Tract ◽  
Virulence Factors ◽  
Stress Responses ◽  
Proteus Mirabilis ◽  
Immune Cell ◽  
Polymyxin B ◽  
Urothelial Cells ◽  
Cationic Antimicrobial Peptide ◽  
Content Type ◽  
Tract Infections

Proteus mirabilisis a common human pathogen causing recurrent or persistent urinary tract infections (UTIs). The underlying mechanisms forP. mirabilisto 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 regulatingmrpI, 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 fromrpoEmutant but not from the wild type. These RpoE-associated virulence factors should be coordinately expressed to enhance the fitness ofP. mirabilisin the host, including the avoidance of immune attacks. Accordingly,rpoEmutant-infected mice displayed more immune cell infiltration in bladders and kidneys during early stages of infection, and therpoEmutant 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 ofrpoEby 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 ofP. mirabilis, to build up a UTI.

scholarly journals Vaccination with Proteus Toxic Agglutinin, a Hemolysin-Independent Cytotoxin In Vivo, Protects against Proteus mirabilis Urinary Tract Infection

2008 ◽  
Vol 77 (2) ◽  
pp. 632-641 ◽  
Author(s):  
Praveen Alamuri ◽  
Kathryn A. Eaton ◽  
Stephanie D. Himpsl ◽  
Sara N. Smith ◽  
Harry L. T. Mobley
Keyword(s):  
Urinary Tract ◽  
Proteus Mirabilis ◽  
Parent Strain ◽  
Double Mutant ◽  
Vaccine Development ◽  
Histopathological Examination ◽  
Bacterial Load ◽  
Passenger Domain ◽  
Tract Infections

ABSTRACT Complicated urinary tract infections (UTI) caused by Proteus mirabilis are associated with severe pathology in the bladder and kidney. To investigate the roles of two established cytotoxins, the HpmA hemolysin, a secreted cytotoxin, and proteus toxic agglutinin (Pta), a surface-associated cytotoxin, mutant analysis was used in conjunction with a mouse model of ascending UTI. Inactivation of pta, but not inactivation of hpmA, resulted in significant decreases in the bacterial loads of the mutant in kidneys (P < 0.01) and spleens (P < 0.05) compared to the bacterial loads of the wild type; the 50% infective dose (ID50) of an isogenic pta mutant or hpmA pta double mutant was 100-fold higher (5 × 108 CFU) than the ID50 of parent strain HI4320 (5 × 106 CFU). Colonization by the parent strain caused severe cystitis and interstitial nephritis as determined by histopathological examination. Mice infected with the same bacterial load of the hpmA pta double mutant showed significantly reduced pathology (P < 0.01), suggesting that the additive effect of these two cytotoxins is critical during Proteus infection. Since Pta is surface associated and important for the persistence of P. mirabilis in the host, it was selected as a vaccine candidate. Mice intranasally vaccinated with a site-directed (indicated by an asterisk) (S366A) mutant purified intact toxin (Pta*) or the passenger domain Pta-α*, each independently conjugated with cholera toxin (CT), had significantly lower bacterial counts in their kidneys ( P = 0.001) and spleens (P = 0.002) than mice that received CT alone. The serum immunoglobulin G levels correlated with protection (P = 0.03). This is the first report describing the in vivo cytotoxicity and antigenicity of an autotransporter in P. mirabilis and its use in vaccine development.

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

Microbiology ◽  
2006 ◽  
Vol 152 (7) ◽  
pp. 2149-2157 ◽  
Author(s):  
Vanessa Sosa ◽  
Geraldine Schlapp ◽  
Pablo Zunino
Keyword(s):  
Urinary Tract ◽  
Virulence Factors ◽  
Proteus Mirabilis ◽  
Protein Patterns ◽  
Wide Range ◽  
Urease Production ◽  
Tract Infections ◽  
Different Origins

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.

scholarly journals The type III secretion system of Proteus mirabilis HI4320 does not contribute to virulence in the mouse model of ascending urinary tract infection

2007 ◽  
Vol 56 (10) ◽  
pp. 1277-1283 ◽  
Author(s):  
Melanie M. Pearson ◽  
Harry L. T. Mobley
Keyword(s):  
Urinary Tract ◽  
Mouse Model ◽  
Proteus Mirabilis ◽  
Type Iii Secretion ◽  
Type Iii Secretion System ◽  
Secretion System ◽  
Negative Regulator ◽  
Wild Type ◽  
Type Iii ◽  
Tract Infections

The Gram-negative enteric bacterium Proteus mirabilis is a frequent cause of urinary tract infections (UTIs) in individuals with long-term indwelling catheters or with complicated urinary tracts. The recent release of the P. mirabilis strain HI4320 genome sequence has facilitated identification of potential virulence factors in this organism. Genes appearing to encode a type III secretion system (TTSS) were found in a low GC-content pathogenicity island in the P. mirabilis chromosome. This island contains 24 intact genes that appear to encode all components necessary to assemble a TTSS needle complex, plus at least two putative secreted effector proteins and their chaperones. The genetic organization of the TTSS genes is very similar to that of the TTSS of Shigella flexneri. RT-PCR analysis indicated that these genes are expressed at low levels in vitro. However, insertional mutation of two putative TTSS genes, encoding the requisite ATPase and a possible negative regulator, resulted in no change in either the growth rate of the mutant or the secreted protein profile compared to wild-type. Furthermore, there was no difference in quantitative cultures of urine, bladder and kidney between the ATPase mutant and the wild-type strain in the mouse model of ascending UTI in either independent challenge or co-challenge experiments. The role of the P. mirabilis TTSS, if any, is yet to be determined.

scholarly journals TonB-Dependent Systems of Uropathogenic Escherichia coli: Aerobactin and Heme Transport and TonB Are Required for Virulence in the Mouse

2001 ◽  
Vol 69 (10) ◽  
pp. 6179-6185 ◽  
Author(s):  
Alfredo G. Torres ◽  
Peter Redford ◽  
Rodney A. Welch ◽  
Shelley M. Payne
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Mouse Model ◽  
Iron Transport ◽  
Iron Acquisition ◽  
Transport Systems ◽  
Model Mouse ◽  
Strain Cft073 ◽  
The Individual ◽  
Tract Infections

ABSTRACT The uropathogenic Escherichia coli strain CFT073 has multiple iron acquisition systems, including heme and siderophore transporters. A tonB mutant derivative of CFT073 failed to use heme as an iron source or to utilize the siderophores enterobactin and aerobactin, indicating that transport of these compounds in CFT073 is TonB dependent. The TonB−derivative showed reduced virulence in a mouse model of urinary tract infection. Virulence was restored when the tonB gene was introduced on a plasmid. To determine the importance of the individual TonB-dependent iron transport systems during urinary tract infections, mutants defective in each of the CFT073 high-affinity iron transport systems were constructed and tested in the mouse model. Mouse virulence assays indicated that mutants defective in a single iron transport system were able to infect the kidney when inoculated as a pure culture but were unable to efficiently compete with the wild-type strain in mixed infections. These results indicate a role for TonB-dependent systems in the virulence of uropathogenic E. coli strains.

Proteus mirabilis from community-acquired urinary tract infections (UTI-CA) shares genetic similarity and virulence factors with isolates from chicken, beef and pork meat

2021 ◽  
pp. 105098
Author(s):  
Matheus Silva Sanches ◽  
Caroline Rodrigues da Silva ◽  
Luana Carvalho Silva ◽  
Victor Hugo Montini ◽  
Mario Gabriel Lopes Barboza ◽  
...  
Keyword(s):  
Urinary Tract ◽  
Virulence Factors ◽  
Urinary Tract Infections ◽  
Proteus Mirabilis ◽  
Genetic Similarity ◽  
Pork Meat ◽  
Tract Infections

Urinary Tract Infections in Patients with Type 1 and Type 2 Diabetes: Etiology, Resistance to Antibacterial Chemicals and Virulence Features

2017 ◽  
Vol 68 (3) ◽  
pp. 566-569 ◽  
Author(s):  
Mihaela Magdalena Mitache ◽  
Carmen Curutiu ◽  
Elena Rusu ◽  
Ramona Bahna ◽  
Mara Ditu ◽  
...  
Keyword(s):  
Urinary Tract ◽  
Virulence Factors ◽  
Urinary Tract Infections ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Diabetic Patients ◽  
Disk Diffusion Test ◽  
Tract Infections ◽  
Susceptibility Profiles ◽  
Diabetes Patients

One of the most frequent chronic complications occurred in diabetes patients are the urinary tract infections (UTIs). This study aimed to investigate the incidence of UTIs in a cohort of 93 (47 males: 46 females) diabetic patients, the prevalence of different microbial species involved and their virulence and antibiotic resistance profiles. The identification of the uropathogenic strains in the positive urine samples was performed using conventional methods and API tests. After identification, the antibiotic susceptibility profiles were established by the standardized disk diffusion method and double disk diffusion test was performed for the confirmation of ESBL and inducible AmpC b �lactamase phenotypes. The isolated strains were tested for the production of different cell associated and soluble virulence factors, i.e.: bacterial adherence to cellular substrata (HeLa cells), hemolysins (hemolysis spot, CAMP-like), amylase, caseinase, aesculin hydrolysis, DNA-ase, lipase and lecithinase. In the analyzed group, the total prevalence of UTIs was of 46%, a higher incidence being observed in the female patients (64%). Similar to other studies, the etiology of UTI in the investigated diabetes patients was dominated by E. coli, followed by Klebsiella sp. strains. The isolated strains preserved good susceptibility rates to quinolones and aminoglycosides and revealed important virulence features, related to their capacity to colonize the cellular substratum and to produce soluble virulence factors involved in persistence, colonization and progression of the infectious process. The high percentage of beta-lactam resistant strains (including carbapenem-resistant ones) requires careful surveillance of the dynamics of susceptibility profiles for limiting the emergence of these strains in community.

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