scholarly journals Derepression of the smvA Efflux System Arises in Clinical Isolates of Proteus mirabilis and Reduces Susceptibility to Chlorhexidine and Other Biocides

2019 ◽  
Vol 63 (12) ◽  
Author(s):  
H. Pelling ◽  
L. J. Bock ◽  
J. Nzakizwanayo ◽  
M. E. Wand ◽  
E. L. Denham ◽  
...  
Keyword(s):  
Urinary Tract ◽  
Proteus Mirabilis ◽  
Polymyxin B ◽  
Clinical Isolates ◽  
Efflux System ◽  
Content Type ◽  
Common Pathogen

ABSTRACT Proteus mirabilis is a common pathogen of the catheterized urinary tract and often described as intrinsically resistant to the biocide chlorhexidine (CHD). Here, we demonstrate that derepression of the smvA efflux system has occurred in clinical isolates of P. mirabilis and reduces susceptibility to CHD and other cationic biocides. Compared with other isolates examined, P. mirabilis RS47 exhibited a significantly higher CHD MIC (≥512 μg/ml) and significantly greater expression of smvA. Comparison of the RS47 smvA and cognate smvR repressor with sequences from other isolates indicated that RS47 carries an inactivated smvR. Complementation of RS47 with a functional smvR from isolate RS50a (which exhibited the lowest smvA expression and lowest CHD MIC) reduced smvA expression by ∼59-fold and markedly lowered the MIC of CHD and other cationic biocides. Although complementation of RS47 did not reduce MICs to concentrations observed in isolate RS50a, the significantly lower polymyxin B MIC of RS50a indicated that differences in lipopolysaccharide (LPS) structure are also a factor in P. mirabilis CHD susceptibility. To determine if exposure to CHD can select for mutations in smvR, clinical isolates with the lowest CHD MICs were adapted to grow at increasing concentrations of CHD up to 512 μg/ml. Analysis of the smvR in adapted populations indicated that mutations predicted to inactivate smvR occurred following CHD exposure in some isolates. Collectively, our data show that smvA derepression contributes to reduced biocide susceptibility in P. mirabilis, but differences in LPS structure between strains are also likely to be an important factor.

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 Single Clinical Isolates from Acute Uncomplicated Urinary Tract Infections Are Representative of Dominant In Situ Populations

mBio ◽  
2014 ◽  
Vol 5 (2) ◽  
Author(s):  
Dana Willner ◽  
Serene Low ◽  
Jason A. Steen ◽  
Narelle George ◽  
Graeme R. Nimmo ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Clinical Isolates ◽  
Content Type ◽  
E Coli ◽  
Strain Diversity ◽  
Amplicon Pyrosequencing ◽  
Culture Independent ◽  
Tract Infections

ABSTRACTUrinary tract infections (UTIs) are one of the most commonly acquired bacterial infections in humans, and uropathogenicEscherichia colistrains are responsible for over 80% of all cases. The standard method for identification of uropathogens in clinical laboratories is cultivation, primarily using solid growth media under aerobic conditions, coupled with morphological and biochemical tests of typically a single isolate colony. However, these methods detect only culturable microorganisms, and characterization is phenotypic in nature. Here, we explored the genotypic identity of communities in acute uncomplicated UTIs from 50 individuals by using culture-independent amplicon pyrosequencing and whole-genome and metagenomic shotgun sequencing. Genus-level characterization of the UTI communities was achieved using the 16S rRNA gene (V8 region). Overall UTI community richness was very low in comparison to other human microbiomes. We strain-typedEscherichia-dominated UTIs using amplicon pyrosequencing of the fimbrial adhesin gene,fimH. There were nine highly abundantfimHtypes, and each UTI sample was dominated by a single type. Molecular analysis of the corresponding clinical isolates revealed that in the majority of cases the isolate was representative of the dominant taxon in the community at both the genus and the strain level. Shotgun sequencing was performed on a subset of eightE. coliurine UTI and isolate pairs. The majority of UTI microbial metagenomic sequences mapped to isolate genomes, confirming the results obtained using phylogenetic markers. We conclude that for the majority of acute uncomplicatedE. coli-mediated UTIs, single cultured isolates are diagnostic of the infection.IMPORTANCEIn clinical practice, the diagnosis and treatment of acute uncomplicated urinary tract infection (UTI) are based on analysis of a single bacterial isolate cultured from urine, and it is assumed that this isolate represents the dominant UTI pathogen. However, these methods detect only culturable bacteria, and the existence of multiple pathogens as well as strain diversity within a single infection is not examined. Here, we explored bacteria present in acute uncomplicated UTIs using culture-independent sequence-based methods.Escherichia coliwas the most common organism identified, and analysis ofE. colidominant UTI samples and their paired clinical isolates revealed that in the majority of infections the cultured isolate was representative of the dominant taxon at both the genus and the strain level. Our data demonstrate that in most cases single cultured isolates are diagnostic of UTI and are consistent with the notion of bottlenecks that limit strain diversity during UTI pathogenesis.

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.

scholarly journals Draft Genome Sequence of Proteus mirabilis Strain UMB0038, Isolated from the Female Bladder

2020 ◽  
Vol 9 (21) ◽  
Author(s):  
Noreen Gallian ◽  
Taylor Miller-Ensminger ◽  
Adelina Voukadinova ◽  
Alan J. Wolfe ◽  
Catherine Putonti
Keyword(s):  
Urinary Tract ◽  
Genome Sequence ◽  
Proteus Mirabilis ◽  
Lower Urinary Tract ◽  
Draft Genome ◽  
Draft Genome Sequence ◽  
Content Type ◽  
Urinary Tract Symptoms ◽  
Female Bladder ◽  
Lower Urinary

ABSTRACT Proteus mirabilis is a Gram-negative motile and rod-shaped bacterium that is a common pathogen of the urinary tract. Here, we report the draft genome sequence of P. mirabilis UMB0038, which was isolated from a woman without lower urinary tract symptoms.

scholarly journals Transcriptome of Proteus mirabilis in the Murine Urinary Tract: Virulence and Nitrogen Assimilation Gene Expression

2011 ◽  
Vol 79 (7) ◽  
pp. 2619-2631 ◽  
Author(s):  
Melanie M. Pearson ◽  
Alejandra Yep ◽  
Sara N. Smith ◽  
Harry L. T. Mobley
Keyword(s):  
Gene Expression ◽  
Urinary Tract ◽  
Glutamate Dehydrogenase ◽  
Proteus Mirabilis ◽  
Transcriptional Analysis ◽  
Broth Culture ◽  
Pathogenic Potential ◽  
Content Type ◽  
Tract Infections

ABSTRACTThe enteric bacteriumProteus mirabilisis a common cause of complicated urinary tract infections. In this study, microarrays were used to analyzeP. mirabilisgene expressionin vivofrom experimentally infected mice. Urine was collected at 1, 3, and 7 days postinfection, and RNA was isolated from bacteria in the urine for transcriptional analysis. Across nine microarrays, 471 genes were upregulated and 82 were downregulatedin vivocompared toin vitrobroth culture. Genes upregulatedin vivoencoded mannose-resistantProteus-like (MR/P) fimbriae, urease, iron uptake systems, amino acid and peptide transporters, pyruvate metabolism enzymes, and a portion of the tricarboxylic acid (TCA) cycle enzymes. Flagella were downregulated. Ammonia assimilation geneglnA(glutamine synthetase) was repressedin vivo, whilegdhA(glutamate dehydrogenase) was upregulatedin vivo. Contrary to our expectations, ammonia availability due to urease activity inP. mirabilisdid not drive this gene expression. AgdhAmutant was growth deficient in minimal medium with citrate as the sole carbon source, and loss ofgdhAresulted in a significant fitness defect in the mouse model of urinary tract infection. UnlikeEscherichia coli, which repressesgdhAand upregulatesglnAin vivoand cannot utilize citrate, the data suggest thatP. mirabilisuses glutamate dehydrogenase to monitor carbon-nitrogen balance, and this ability contributes to the pathogenic potential ofP. mirabilisin the urinary tract.

scholarly journals Identification of Extended-Spectrum-β-Lactamase-Positive Klebsiella pneumoniae Urinary Tract Isolates Harboring KPC and CTX-M β-Lactamases in Nonhospitalized Patients

2013 ◽  
Vol 57 (10) ◽  
pp. 5166-5169 ◽  
Author(s):  
Joanna Kopacz ◽  
Noriel Mariano ◽  
Rita Colon-Urban ◽  
Paul Sychangco ◽  
Wehbeh Wehbeh ◽  
...  
Keyword(s):  
Urinary Tract ◽  
Klebsiella Pneumoniae ◽  
Polymyxin B ◽  
Invasive Disease ◽  
Content Type ◽  
Extended Spectrum ◽  
Risk Of Progression

ABSTRACTForty-seven extended-spectrum-β-lactamase-positiveKlebsiella pneumoniaeurinary tract isolates from nonhospitalized patients were identified, and 79% harbored KPC and/or CTX-M β-lactamases. Approximately 90% of the isolates were resistant to trimethoprim-sulfamethoxazole and levofloxacin, and 40% were resistant to a carbapenem, while 92% were susceptible to polymyxin B, 87% were susceptible to tigecycline, and 79% were susceptible to fosfomycin. Increased use of broader-spectrum antibiotics may help to prevent their dissemination and reduce the risk of progression to invasive disease.

scholarly journals Complete Genome Sequence of Proteus mirabilis Phage Myduc

2019 ◽  
Vol 8 (47) ◽  
Author(s):  
Jennifer Tran ◽  
Lauren Lessor ◽  
Chandler O’Leary ◽  
Jason Gill ◽  
Mei Liu
Keyword(s):  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Genome Sequence ◽  
Proteus Mirabilis ◽  
Complete Genome Sequence ◽  
Complete Genome ◽  
Nosocomial Pathogen ◽  
Content Type ◽  
Small Genome ◽  
Tract Infections

Proteus mirabilis as a nosocomial pathogen is often the cause of urinary tract infections. This announcement describes the complete genome sequence of a P. mirabilis myophage named Myduc. Phage Myduc is related to Enterobacteria phage phiEcoM-GJ1, which belongs to a group of myophages with small genome sizes (52,000 to 56,000 bp) possessing a T7-like RNA polymerase.

scholarly journals Elucidating the Genetic Basis of Crystalline Biofilm Formation in Proteus mirabilis

2014 ◽  
Vol 82 (4) ◽  
pp. 1616-1626 ◽  
Author(s):  
N. Holling ◽  
D. Lednor ◽  
S. Tsang ◽  
A. Bissell ◽  
L. Campbell ◽  
...  
Keyword(s):  
Urinary Tract ◽  
Proteus Mirabilis ◽  
Biofilm Formation ◽  
Efflux Pump ◽  
Model Systems ◽  
Multidrug Efflux Pump ◽  
Gene Encoding ◽  
Content Type ◽  
Biofilm Development

ABSTRACTProteus mirabilisforms extensive crystalline biofilms on urethral catheters that occlude urine flow and frequently complicate the management of long-term-catheterized patients. Here, using random transposon mutagenesis in conjunction within vitromodels of the catheterized urinary tract, we elucidate the mechanisms underpinning the formation of crystalline biofilms byP. mirabilis. Mutants identified as defective in blockage of urethral catheters had disruptions in genes involved in nitrogen metabolism and efflux systems but were unaffected in general growth, survival in bladder model systems, or the ability to elevate urinary pH. Imaging of biofilms directly on catheter surfaces, along with quantification of levels of encrustation and biomass, confirmed that the mutants were attenuated specifically in the ability to form crystalline biofilms compared with that of the wild type. However, the biofilm-deficient phenotype of these mutants was not due to deficiencies in attachment to catheter biomaterials, and defects in later stages of biofilm development were indicated. For one blocking-deficient mutant, the disrupted gene (encoding a putative multidrug efflux pump) was also found to be associated with susceptibility to fosfomycin, and loss of this system or general inhibition of efflux pumps increased sensitivity to this antibiotic. Furthermore, homologues of this system were found to be widely distributed among other common pathogens of the catheterized urinary tract. Overall, our findings provide fundamental new insight into crystalline biofilm formation byP. mirabilis, including the link between biofilm formation and antibiotic resistance in this organism, and indicate a potential role for efflux pump inhibitors in the treatment or prevention ofP. mirabiliscrystalline biofilms.

scholarly journals Mutations in Ribosomal Protein RplA or Treatment with Ribosomal Acting Antibiotics Activates Production of Aminoglycoside Efflux Pump SmeYZ in Stenotrophomonas maltophilia

2019 ◽  
Vol 64 (2) ◽  
Author(s):  
Karina Calvopiña ◽  
Punyawee Dulyayangkul ◽  
Matthew B. Avison
Keyword(s):  
Ribosomal Protein ◽  
Stenotrophomonas Maltophilia ◽  
Efflux Pump ◽  
Clinical Isolates ◽  
Efflux System ◽  
Aminoglycoside Resistance ◽  
Content Type ◽  
Ribosomal Protein L1 ◽  
Significant Mechanism

ABSTRACT Aminoglycoside resistance in Stenotrophomonas maltophilia is multifactorial, but the most significant mechanism is overproduction of the SmeYZ efflux system. By studying laboratory-selected mutants and clinical isolates, we show here that damage to the 50S ribosomal protein L1 (RplA) activates SmeYZ production. We also show that gentamicin and minocycline, which target the ribosome, induce expression of smeYZ. These findings explain the role of SmeYZ in both intrinsic and mutationally acquired aminoglycoside resistance.

scholarly journals Polymyxin Susceptibility in Pseudomonas aeruginosa Linked to the MexXY-OprM Multidrug Efflux System

2015 ◽  
Vol 59 (12) ◽  
pp. 7276-7289 ◽  
Author(s):  
Keith Poole ◽  
Calvin Ho-Fung Lau ◽  
Christie Gilmour ◽  
Youai Hao ◽  
Joseph S. Lam
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Resistance Mechanism ◽  
Polymyxin B ◽  
Wild Type ◽  
Multidrug Efflux ◽  
Efflux System ◽  
Content Type ◽  
Polymyxin E ◽  
Increased Susceptibility ◽  
Multidrug Efflux System

ABSTRACTThe ribosome-targeting antimicrobial, spectinomycin (SPC), strongly induced themexXYgenes of the MexXY-OprM multidrug efflux system inPseudomonas aeruginosaand increased susceptibility to the polycationic antimicrobials polymyxin B and polymyxin E, concomitant with a decrease in expression of the polymyxin resistance-promoting lipopolysaccharide (LPS) modification loci,arnBCADTEFand PA4773-74. Consistent with the SPC-promoted reduction inarnand PA4773-74 expression being linked tomexXY, expression of these LPS modification loci was moderated in a mutant constitutively expressingmexXYand enhanced in a mutant lacking the efflux genes. Still, the SPC-mediated increase in polymyxin susceptibility was retained in mutants lackingarnBand/or PA4773-74, an indication that their reduced expression in SPC-treated cells does not explain the enhanced polymyxin susceptibility. That the polymyxin susceptibility of a mutant strain lackingmexXYwas unaffected by SPC exposure, however, was an indication that the unknown polymyxin resistance ‘mechanism’ is also influenced by the MexXY status of the cell. In agreement with SPC and MexXY influencing polymyxin susceptibility as a result of changes in the LPS target of these agents, SPC treatment yielded a decline in common polysaccharide antigen (CPA) synthesis in wild-typeP. aeruginosabut not in the ΔmexXYmutant. A mutant lacking CPA still showed the SPC-mediated decline in polymyxin MICs, however, indicating that the loss of CPA did not explain the SPC-mediated MexXY-dependent increase in polymyxin susceptibility. It is possible, therefore, that some additional change in LPS promoted by SPC-inducedmexXYexpression impacted CPA synthesis or its incorporation into LPS and that this was responsible for the observed changes in polymyxin susceptibility.

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