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Stolarek P, Bernat P, Różalski A. Adjustment in the Composition and Organization of Proteus mirabilis Lipids during the Swarming Process. Int J Mol Sci 2023; 24:16461. [PMID: 38003652 PMCID: PMC10671106 DOI: 10.3390/ijms242216461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 11/07/2023] [Accepted: 11/15/2023] [Indexed: 11/26/2023] Open
Abstract
Proteus mirabilis, an opportunistic pathogen of the urinary tract, is known for its dimorphism and mobility. A connection of lipid alterations, induced by the rods elongation process, with enhanced pathogenicity of long-form morphotype for the development of urinary tract infections, seems highly probable. Therefore, research on the adjustment in the composition and organization of P. mirabilis lipids forming elongated rods was undertaken. The analyses performed using the ultra-high performance liquid chromatography with tandem mass spectrometry showed that drastic modifications in the morphology of P. mirabilis rods that occur during the swarming process are directly related to deprivation of the long-form cells of PE 33:1 and PG 31:2 and their enrichment with PE 32:1, PE 34:1, PE 34:2, PG 30:2, PG 32:1, and PG 34:1. The analyses conducted by the gas chromatography-mass spectrometry showed negligible effects of the swarming process on fatty acids synthesis. However, the constant proportions between unsaturated and saturated fatty acids confirmed that phenotypic modifications in the P. mirabilis rods induced by motility were independent of the saturation of the phospholipid tails. The method of the Förster resonance energy transfer revealed the influence of the swarming process on the melting of ordered lipid rafts present in the short-form rods, corresponding to the homogeneity of lipid bilayers in the long-form rods of P. mirabilis. Confocal microscope photographs visualized strong Rhod-PE fluorescence of the whole area of swarmer cells, in contrast to weak membrane fluorescence of non-swarmer cells. It suggested an increased permeability of the P. mirabilis bilayers in long-form rods morphologically adapted to the swarming process. These studies clearly demonstrate that swarming motility regulates the lipid composition and organization in P. mirabilis rods.
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Affiliation(s)
- Paulina Stolarek
- Department of Biology of Bacteria, Faculty of Biology and Environmental Protection, University of Lodz, Banacha 12/16, 90-237 Lodz, Poland;
| | - Przemysław Bernat
- Department of Industrial Microbiology and Biotechnology, Faculty of Biology and Environmental Protection, University of Lodz, Banacha 12/16, 90-237 Lodz, Poland;
| | - Antoni Różalski
- Department of Biology of Bacteria, Faculty of Biology and Environmental Protection, University of Lodz, Banacha 12/16, 90-237 Lodz, Poland;
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Bru JL, Kasallis SJ, Zhuo Q, Høyland-Kroghsbo NM, Siryaporn A. Swarming of P. aeruginosa: Through the lens of biophysics. BIOPHYSICS REVIEWS 2023; 4:031305. [PMID: 37781002 PMCID: PMC10540860 DOI: 10.1063/5.0128140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 08/29/2023] [Indexed: 10/03/2023]
Abstract
Swarming is a collective flagella-dependent movement of bacteria across a surface that is observed across many species of bacteria. Due to the prevalence and diversity of this motility modality, multiple models of swarming have been proposed, but a consensus on a general mechanism for swarming is still lacking. Here, we focus on swarming by Pseudomonas aeruginosa due to the abundance of experimental data and multiple models for this species, including interpretations that are rooted in biology and biophysics. In this review, we address three outstanding questions about P. aeruginosa swarming: what drives the outward expansion of a swarm, what causes the formation of dendritic patterns (tendrils), and what are the roles of flagella? We review models that propose biologically active mechanisms including surfactant sensing as well as fluid mechanics-based models that consider swarms as thin liquid films. Finally, we reconcile recent observations of P. aeruginosa swarms with early definitions of swarming. This analysis suggests that mechanisms associated with sliding motility have a critical role in P. aeruginosa swarm formation.
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Affiliation(s)
- Jean-Louis Bru
- Department of Molecular Biology and Biochemistry, University of California Irvine, Irvine, California 92697, USA
| | - Summer J. Kasallis
- Department of Physics and Astronomy, University of California Irvine, Irvine, California 92697, USA
| | - Quantum Zhuo
- Department of Physics and Astronomy, University of California Irvine, Irvine, California 92697, USA
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3
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Sheng Q, Liu A, Yang P, Chen Z, Wang P, Sun H, Li C, McMinn A, Chen Y, Zhang Y, Su H, Chen X, Zhang Y. The FilZ Protein Contains a Single PilZ Domain and Facilitates the Swarming Motility of Pseudoalteromonas sp. SM9913. Microorganisms 2023; 11:1566. [PMID: 37375068 DOI: 10.3390/microorganisms11061566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2023] [Revised: 06/03/2023] [Accepted: 06/06/2023] [Indexed: 06/29/2023] Open
Abstract
Swarming regulation is complicated in flagellated bacteria, especially those possessing dual flagellar systems. It remains unclear whether and how the movement of the constitutive polar flagellum is regulated during swarming motility of these bacteria. Here, we report the downregulation of polar flagellar motility by the c-di-GMP effector FilZ in the marine sedimentary bacterium Pseudoalteromonas sp. SM9913. Strain SM9913 possesses two flagellar systems, and filZ is located in the lateral flagellar gene cluster. The function of FilZ is negatively controlled by intracellular c-di-GMP. Swarming in strain SM9913 consists of three periods. Deletion and overexpression of filZ revealed that, during the period when strain SM9913 expands quickly, FilZ facilitates swarming. In vitro pull-down and bacterial two-hybrid assays suggested that, in the absence of c-di-GMP, FilZ interacts with the CheW homolog A2230, which may be involved in the chemotactic signal transduction pathway to the polar flagellar motor protein FliMp, to interfere with polar flagellar motility. When bound to c-di-GMP, FilZ loses its ability to interact with A2230. Bioinformatic investigation indicated that filZ-like genes are present in many bacteria with dual flagellar systems. Our findings demonstrate a novel mode of regulation of bacterial swarming motility.
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Affiliation(s)
- Qi Sheng
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Ang Liu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Peiling Yang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Zhuowei Chen
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Peng Wang
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, College of Marine Life Sciences, Ocean University of China, Qingdao 266100, China
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao 266237, China
| | - Haining Sun
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Chunyang Li
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, College of Marine Life Sciences, Ocean University of China, Qingdao 266100, China
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao 266237, China
| | - Andrew McMinn
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, College of Marine Life Sciences, Ocean University of China, Qingdao 266100, China
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS 7005, Australia
| | - Yin Chen
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, College of Marine Life Sciences, Ocean University of China, Qingdao 266100, China
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
| | - Yuzhong Zhang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, College of Marine Life Sciences, Ocean University of China, Qingdao 266100, China
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao 266237, China
| | - Hainan Su
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Xiulan Chen
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao 266237, China
| | - Yuqiang Zhang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
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Antimicrobial Resistance and Virulence Factors of Proteus mirabilis Isolated from Dog with Chronic Otitis Externa. Pathogens 2022; 11:pathogens11101215. [PMID: 36297273 PMCID: PMC9612330 DOI: 10.3390/pathogens11101215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Revised: 10/17/2022] [Accepted: 10/20/2022] [Indexed: 11/05/2022] Open
Abstract
Otitis externa is among the most prevalent diseases in dogs. If the underlying cause is not addressed, bacterial reinfection becomes frequent, necessitating antibiotic administration for an extended period of time. Prolonged treatment promotes the emergence of antibiotic-resistant bacteria and increases the risk of their transmission from animals to humans. This study aimed to analyze the antibiotic resistance pattern of the emerging pathogen Proteus mirabilis to identify bacterial virulence and antibiotic selection. Samples were collected from randomly encountered dogs with chronic otitis externa. Thirty-two strains of P. mirabilis were isolated and identified, using MALDI-TOF. The Kirby-Bauer disk diffusion method was used to assess the antibiotic susceptibility of P. mirabilis to 11 antibiotics. The isolates (n = 32) were most resistant to cefazolin (75%), trimethoprim–sulfamethoxazole (72%), chloramphenicol (72%), amoxicillin–clavulanate (63%), ampicillin (59%), cefepime (56%), ciprofloxacin (53%), aztreonam (50%), ceftazidime avibactam (50%), gentamicin (22%), and amikacin (16%). Moreover, 75% of isolates were found to be multidrug-resistant bacteria. P. mirabilis was found to have a high resistance-pattern ratio. Although the exact cause is unknown, continuous antibiotic use is thought to be a major factor. We concluded that antibiotic use must be prudent and selective to prevent antibiotic resistance.
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Butement JT, Noel DJ, Bryant CA, Wilks SA, Eason RW. A light-guiding urinary catheter for the inhibition of Proteus mirabilis biofilm formation. Front Microbiol 2022; 13:995200. [PMID: 36204628 PMCID: PMC9530263 DOI: 10.3389/fmicb.2022.995200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 08/30/2022] [Indexed: 11/13/2022] Open
Abstract
Catheter-associated urinary tract infection (CAUTI) is a leading cause of hospital-acquired infections worldwide causing debilitating illness for patients as well as a significant financial and treatment burden on health services. CAUTI is linked with the build-up of biofilms on catheter surfaces which act as a reservoir for infection. Additionally, urease-producing bacteria such as Gram-negative Proteus mirabilis (PM), can form crystalline biofilms which encrust catheter surfaces ultimately leading to blockages which require immediate removal of the catheter. Currently there are limited treatments available to prevent the formation of biofilms by PM as well as other urinary tract infection causing bacteria. A novel concept for a light-guiding urinary catheter is presented where a silicone elastomer waveguide incorporated along the length of the catheter is used to irradiate the catheter surfaces with antimicrobial blue light (405 nm) to prevent biofilm formation in situ. The prototype device is mass producible while also easy to fabricate in a lab setting for research studies. The inhibitory effect of blue light on PM biofilm formation over a range of irradiances is described for the first time showing an LD90 at 192–345 J/cm2 and total inhibition at 1,700 J/cm2In vitro studies show that the light-guiding catheter (LGC) prototypes exhibit a 98% inhibition in PM biofilm formation inside the catheter lumen at an average estimated irradiance of 30–50 mW/cm2 (324–540 J/cm2 fluence) showing that the concept is highly effective, promising to be a powerful and economical antimicrobial approach to prevent catheter associated biofilm development and blockage.
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Affiliation(s)
- Jonathan T. Butement
- Optoelectronics Research Centre, University of Southampton, Southampton, United Kingdom
- *Correspondence: Jonathan T. Butement,
| | - Daniel J. Noel
- School of Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - Catherine A. Bryant
- School of Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - Sandra A. Wilks
- School of Health Sciences, University of Southampton, Southampton, United Kingdom
| | - Robert W. Eason
- Optoelectronics Research Centre, University of Southampton, Southampton, United Kingdom
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Wasfi R, Hamed SM, Amer MA, Fahmy LI. Proteus mirabilis Biofilm: Development and Therapeutic Strategies. Front Cell Infect Microbiol 2020; 10:414. [PMID: 32923408 PMCID: PMC7456845 DOI: 10.3389/fcimb.2020.00414] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Accepted: 07/06/2020] [Indexed: 01/21/2023] Open
Abstract
Proteus mirabilis is a Gram negative bacterium that is a frequent cause of catheter-associated urinary tract infections (CAUTIs). Its ability to cause such infections is mostly related to the formation of biofilms on catheter surfaces. In order to form biofilms, P. mirabilis expresses a number of virulence factors. Such factors may include adhesion proteins, quorum sensing molecules, lipopolysaccharides, efflux pumps, and urease enzyme. A unique feature of P. mirabilis biofilms that build up on catheter surfaces is their crystalline nature owing to their ureolytic biomineralization. This leads to catheter encrustation and blockage and, in most cases, is accompanied by urine retention and ascending UTIs. Bacteria embedded in crystalline biofilms become highly resistant to conventional antimicrobials as well as the immune system. Being refractory to antimicrobial treatment, alternative approaches for eradicating P. mirabilis biofilms have been sought by many studies. The current review focuses on the mechanism by which P. mirabilis biofilms are formed, and a state of the art update on preventing biofilm formation and reduction of mature biofilms. These treatment approaches include natural, and synthetic compounds targeting virulence factors and quorum sensing, beside other strategies that include carrier-mediated diffusion of antimicrobials into biofilm matrix. Bacteriophage therapy has also shown successful results in vitro for combating P. mirabilis biofilms either merely through their lytic effect or by acting as facilitators for antimicrobials diffusion.
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Affiliation(s)
- Reham Wasfi
- Department of Microbiology and Immunology, Faculty of Pharmacy, October University for Modern Sciences and Arts (MSA), Giza, Egypt
| | - Samira M Hamed
- Department of Microbiology and Immunology, Faculty of Pharmacy, October University for Modern Sciences and Arts (MSA), Giza, Egypt
| | - Mai A Amer
- Department of Microbiology and Immunology, Faculty of Pharmacy, October University for Modern Sciences and Arts (MSA), Giza, Egypt
| | - Lamiaa Ismail Fahmy
- Department of Microbiology and Immunology, Faculty of Pharmacy, October University for Modern Sciences and Arts (MSA), Giza, Egypt
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8
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Aygül A, Öztürk İ, Çilli FF, Ermertcan Ş. Quercetin inhibits swarming motility and activates biofilm production of Proteus mirabilis possibly by interacting with central regulators, metabolic status or active pump proteins. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2019; 57:65-71. [PMID: 30668324 DOI: 10.1016/j.phymed.2018.12.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 12/04/2018] [Accepted: 12/10/2018] [Indexed: 06/09/2023]
Abstract
BACKGROUND Via its virulence factors such as swarm differentiation, biofilm and hemolysin production, urease enzyme, Proteus mirabilis causes urinary tract infections (UTIs), especially in complicated cases. Anti-pathogenic compounds attenuate the virulence of bacteria without showing 'cidal' activity and carry the potential to be used in the prevention and treatment of infectious diseases. PURPOSE Search for anti-pathogenic effects of quercetin, which is a widely known and biologically active phytochemical, on Proteus mirabilis was the purpose of this study. In this context, the potential inhibitory activity of quercetin on swarming motility and biofilm production of a wild-type strain, P. mirabilis HI4320, was investigated in both phenotypically and genotypically. METHODS Quercetin's effect on swarming motility was examined on LB agar plates, containing quercetin at various concentrations, by measuring the swarming diameter. The effect on biofilm formation, on the other hand, was analyzed by staining the formed biofilm of the bacterium, exposed to quercetin at various concentrations, with crystal violet and reading spectrophotometrically. Differences in expression levels of selected genes involved in swarming regulation were determined by real-time reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) to evaluate the mechanism of inhibitory action on swarming. Further investigations were carried out repeating swarming assays with the clones that derived from the wild-type strain by a TA system kit for direct one-step cloning and overexpressing the relevant genes. RESULTS Our study revealed that quercetin inhibited swarming motility while activating biofilm production of P. mirabilis in direct proportion to the dose. Although all selected genes are inhibited in the same manner in liquid medium, and no significant differences could be detected in solid medium as demonstrated by RT-qPCR, experiments repeated with the clones overexpressing flhC (a component of flagellar transcriptional activator), speB (an agmatinase enzyme) and ompF (an outer membrane porin) genes showed that the respective clones could restore swarming, compensating for the inhibitory effect of quercetin. CONCLUSION Quercetin's inhibitory effect on P. mirabilis swarming was possibly due to interactions with components of swarming regulators, the genes expressing polyamine coding enzymes that trigger swarm differentiation, or active pump proteins.
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Affiliation(s)
- Abdurrahman Aygül
- Çukurova University, Faculty of Pharmacy, Department of Pharmaceutical Microbiology, Adana 01380, Turkey.
| | - İsmail Öztürk
- İzmir Katip Çelebi University, Faculty of Pharmacy, Department of Pharmaceutical Microbiology, İzmir 35040, Turkey
| | - Fatma Feriha Çilli
- Ege University, Faculty of Medicine, Department of Medical Microbiology, İzmir 35040, Turkey
| | - Şafak Ermertcan
- Ege University, Faculty of Pharmacy, Department of Pharmaceutical Microbiology, İzmir 35040, Turkey
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Pelling H, Nzakizwanayo J, Milo S, Denham EL, MacFarlane WM, Bock LJ, Sutton JM, Jones BV. Bacterial biofilm formation on indwelling urethral catheters. Lett Appl Microbiol 2019; 68:277-293. [PMID: 30811615 DOI: 10.1111/lam.13144] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 02/22/2019] [Accepted: 02/23/2019] [Indexed: 12/21/2022]
Abstract
Urethral catheters are the most commonly deployed medical devices and used to manage a wide range of conditions in both hospital and community care settings. The use of long-term catheterization, where the catheter remains in place for a period >28 days remains common, and the care of these patients is often undermined by the acquisition of infections and formation of biofilms on catheter surfaces. Particular problems arise from colonization with urease-producing species such as Proteus mirabilis, which form unusual crystalline biofilms that encrust catheter surfaces and block urine flow. Encrustation and blockage often lead to a range of serious clinical complications and emergency hospital referrals in long-term catheterized patients. Here we review current understanding of bacterial biofilm formation on urethral catheters, with a focus on crystalline biofilm formation by P. mirabilis, as well as approaches that may be used to control biofilm formation on these devices. SIGNIFICANCE AND IMPACT OF THE STUDY: Urinary catheters are the most commonly used medical devices in many healthcare systems, but their use predisposes to infection and provide ideal conditions for bacterial biofilm formation. Patients managed by long-term urethral catheterization are particularly vulnerable to biofilm-related infections, with crystalline biofilm formation by urease producing species frequently leading to catheter blockage and other serious clinical complications. This review considers current knowledge regarding biofilm formation on urethral catheters, and possible strategies for their control.
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Affiliation(s)
- H Pelling
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath, UK
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, UK
| | - J Nzakizwanayo
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath, UK
| | - S Milo
- Department of Chemistry, University of Bath, Claverton Down, Bath, UK
| | - E L Denham
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath, UK
| | - W M MacFarlane
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, UK
| | - L J Bock
- National Infections Service, Public Health England, Porton Down, Salisbury, UK
| | - J M Sutton
- National Infections Service, Public Health England, Porton Down, Salisbury, UK
| | - B V Jones
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath, UK
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Abstract
Proteus mirabilis, a Gram-negative rod-shaped bacterium most noted for its swarming motility and urease activity, frequently causes catheter-associated urinary tract infections (CAUTIs) that are often polymicrobial. These infections may be accompanied by urolithiasis, the development of bladder or kidney stones due to alkalinization of urine from urease-catalyzed urea hydrolysis. Adherence of the bacterium to epithelial and catheter surfaces is mediated by 17 different fimbriae, most notably MR/P fimbriae. Repressors of motility are often encoded by these fimbrial operons. Motility is mediated by flagella encoded on a single contiguous 54-kb chromosomal sequence. On agar plates, P. mirabilis undergoes a morphological conversion to a filamentous swarmer cell expressing hundreds of flagella. When swarms from different strains meet, a line of demarcation, a "Dienes line," develops due to the killing action of each strain's type VI secretion system. During infection, histological damage is caused by cytotoxins including hemolysin and a variety of proteases, some autotransported. The pathogenesis of infection, including assessment of individual genes or global screens for virulence or fitness factors has been assessed in murine models of ascending urinary tract infections or CAUTIs using both single-species and polymicrobial models. Global gene expression studies performed in culture and in the murine model have revealed the unique metabolism of this bacterium. Vaccines, using MR/P fimbria and its adhesin, MrpH, have been shown to be efficacious in the murine model. A comprehensive review of factors associated with urinary tract infection is presented, encompassing both historical perspectives and current advances.
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Abstract
Proteus mirabilis is well known for using its flagella to swim through liquids or swarm across solid surfaces. Both phenomena are easy to observe. Described here are two agar-based assays for studying both swimming and swarming behavior, and considerations that affect the outcome.
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Affiliation(s)
- Melanie M Pearson
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, USA.
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Gmiter D, Czerwonka G, Drewnowska JM, Swiecicka I, Kaca W. Draft Genome Sequences of Proteus mirabilis K1609 and K670: A Model Strains for Territoriality Examination. Curr Microbiol 2018; 76:144-152. [PMID: 30448962 PMCID: PMC6373192 DOI: 10.1007/s00284-018-1598-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 11/12/2018] [Indexed: 11/26/2022]
Abstract
Proteus mirabilis is a pathogenic Gram-negative bacterium characterized by its ability to swarm across surfaces, which frequently leads to colonization of the urinary tract and causes severe infections. P. mirabilis strains are also well known from their self-recognition phenomenon, referred to as Dienes phenomenon. In this study, we present novel aspect of self-recognition, which is a hierarchy in terms of strains territoriality. We report the draft genome sequences of P. mirabilis K1609 and K670 strains exhibiting the strongest and the weakest territoriality, respectively. Our results indicated that K1609 is closely related to strain BB2000, a model system for self-recognition, comparing with the K670. We annotated genes associated with recognition of kin and swarming initiation control and indicated polymorphisms by which observed differences in territoriality might results from. The phenotypic and genomic features of both strains reveal their application as a model organisms for studying not only the mechanisms of kin-recognition but also strains territoriality, thus providing new approach to the phenomenon. Availability of these genome sequences may facilitate understanding of the interactions between P. mirabilis strains.
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Affiliation(s)
- Dawid Gmiter
- Department of Microbiology, Jan Kochanowski University, 15 Swietokrzyska Street, 25-406, Kielce, Poland.
| | - Grzegorz Czerwonka
- Department of Microbiology, Jan Kochanowski University, 15 Swietokrzyska Street, 25-406, Kielce, Poland
| | - Justyna Malgorzata Drewnowska
- Departament of Microbiology, Institute of Biology, University of Bialystok, 1J Ciolkowskiego Street, 15-245, Bialystok, Poland
| | - Izabela Swiecicka
- Departament of Microbiology, Institute of Biology, University of Bialystok, 1J Ciolkowskiego Street, 15-245, Bialystok, Poland
- Laboratory of Applied Microbiology, University of Bialystok, 1J Ciolkowskiego Street, 15-245, Bialystok, Poland
| | - Wieslaw Kaca
- Department of Microbiology, Jan Kochanowski University, 15 Swietokrzyska Street, 25-406, Kielce, Poland
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MrpJ Directly Regulates Proteus mirabilis Virulence Factors, Including Fimbriae and Type VI Secretion, during Urinary Tract Infection. Infect Immun 2018; 86:IAI.00388-18. [PMID: 30082479 DOI: 10.1128/iai.00388-18] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 07/30/2018] [Indexed: 12/18/2022] Open
Abstract
Proteus mirabilis is a leading cause of catheter-associated urinary tract infections (CAUTIs) and urolithiasis. The transcriptional regulator MrpJ inversely modulates two critical aspects of P. mirabilis UTI progression: fimbria-mediated attachment and flagellum-mediated motility. Transcriptome data indicated a network of virulence-associated genes under MrpJ's control. Here, we identify the direct gene regulon of MrpJ and its contribution to P. mirabilis pathogenesis, leading to the discovery of novel virulence targets. Chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq) was used for the first time in a CAUTI pathogen to probe for in vivo direct targets of MrpJ. Selected MrpJ-regulated genes were mutated and assessed for their contribution to UTI using a mouse model. ChIP-seq revealed a palindromic MrpJ binding sequence and 78 MrpJ-bound regions, including binding sites upstream of genes involved in motility, fimbriae, and a type VI secretion system (T6SS). A combinatorial mutation approach established the contribution of three fimbriae (fim8A, fim14A, and pmpA) to UTI and a new pathogenic role for the T6SS in UTI progression. In conclusion, this study (i) establishes the direct gene regulon and an MrpJ consensus binding site and (ii) led to the discovery of new virulence genes in P. mirabilis UTI, which could be targeted for therapeutic intervention of CAUTI.
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Pawar S, Ashraf MI, Mujawar S, Mishra R, Lahiri C. In silico Identification of the Indispensable Quorum Sensing Proteins of Multidrug Resistant Proteus mirabilis. Front Cell Infect Microbiol 2018; 8:269. [PMID: 30131943 PMCID: PMC6090301 DOI: 10.3389/fcimb.2018.00269] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 07/17/2018] [Indexed: 11/13/2022] Open
Abstract
Catheter-associated urinary tract infections (CAUTI) is an alarming hospital based disease with the increase of multidrug resistance (MDR) strains of Proteus mirabilis. Cases of long term hospitalized patients with multiple episodes of antibiotic treatments along with urinary tract obstruction and/or undergoing catheterization have been reported to be associated with CAUTI. The cases are complicated due to the opportunist approach of the pathogen having robust swimming and swarming capability. The latter giving rise to biofilms and probably inducible through autoinducers make the scenario quite complex. High prevalence of long-term hospital based CAUTI for patients along with moderate percentage of morbidity, cropping from ignorance about drug usage and failure to cure due to MDR, necessitates an immediate intervention strategy effective enough to combat the deadly disease. Several reports and reviews focus on revealing the important genes and proteins, essential to tackle CAUTI caused by P. mirabilis. Despite longitudinal countrywide studies and methodical strategies to circumvent the issues, effective means of unearthing the most indispensable proteins to target for therapeutic uses have been meager. Here, we report a strategic approach for identifying the most indispensable proteins from the genome of P. mirabilis strain HI4320, besides comparing the interactomes comprising the autoinducer-2 (AI-2) biosynthetic pathway along with other proteins involved in biofilm formation and responsible for virulence. Essentially, we have adopted a theoretical network model based approach to construct a set of small protein interaction networks (SPINs) along with the whole genome (GPIN) to computationally identify the crucial proteins involved in the phenomenon of quorum sensing (QS) and biofilm formation and thus, could be therapeutically targeted to fight out the MDR threats to antibiotics of P. mirabilis. Our approach utilizes the functional modularity coupled with k-core analysis and centrality scores of eigenvector as a measure to address the pressing issues.
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Affiliation(s)
- Shrikant Pawar
- Department of Computer Science, Georgia State University, Atlanta, GA, United States.,Department of Biology, Georgia State University, Atlanta, GA, United States
| | - Md Izhar Ashraf
- Department of Computer Applications, B.S. Abdur Rahman Crescent Institute of Science and Technology, Chennai, India.,Theoretical Physics, The Institute of Mathematical Sciences, Chennai, India
| | - Shama Mujawar
- Department of Biological Sciences, Sunway University, Petaling Jaya, Malaysia
| | - Rohit Mishra
- Department of Bioinformatics, G.N. Khalsa College, University of Mumbai, Mumbai, India
| | - Chandrajit Lahiri
- Department of Biological Sciences, Sunway University, Petaling Jaya, Malaysia
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15
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Naseri H, Sharifi A, Ghaedi M, Dashtian K, Khoramrooz SS, Manzouri L, Khosravani SA, Pezeshkpour V, Sadri F, Askarinia M. Sonochemical incorporated of cytosine in Cu-H 2bpdc as an antibacterial agent against standard and clinical strains of Proteus mirabilis with rsbA gene. ULTRASONICS SONOCHEMISTRY 2018; 44:223-230. [PMID: 29680606 DOI: 10.1016/j.ultsonch.2018.02.031] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 01/09/2018] [Accepted: 02/18/2018] [Indexed: 06/08/2023]
Abstract
The cytosine embedded copper based metal-organic framework (Bio-MOF) was synthesized by facile one-step sonochemical method by simply mixing of 4-4, biphenyldicarboxylic, cytosine and copper nitrate (Bio-Cu-H2bpdc-Cy). The prepared bio-MOF was characterized by XRD, FTIR and FE-SEM techniques. The effect of Cu-H2bpdc-Cy on the expression of the rsbA gene was evaluated in the clinical and standard Proteus mirabilis and study of MIC of Cu-H2bpdc-Cy by microdilution against them that have the rsbA gene. According to different concentrations of MIC, MBC concentrations was cultured on blood agar culture medium. Regarding to the concentration of MIC, gene expression changes were obtained by real-time PCR. MIC for standard and clinical strains of Proteus mirabilis was 1.6 and 1.8 mg/ml, and also MBC was obtained to be 1.8 and 2.0 mg/ml, respectively. Finally, in the real time PCR method, expression of the rsbA gene in presences of bio-Cu-H2bpdc-Cy was reduced, but has no effect on the gene expression of the Housekeeping DNA Gyrase-B gene. Considering the effect of Cu-H2bpdc-Cy on the rsbA gene in Proteus mirabilis bacteria, it is possible to use of Cu-H2bpdc-Cy agent as a therapeutic supplement against this bacterium.
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Affiliation(s)
- Hajar Naseri
- Cellular and Molecular Research Center, Yasuj University of Medical Sciences, Yasuj, IR, Iran; Student Research Committee, Yasuj University of Medical Sciences, Yasuj, Iran
| | - Asghar Sharifi
- Cellular and Molecular Research Center, Yasuj University of Medical Sciences, Yasuj, IR, Iran.
| | - Mehrorang Ghaedi
- Department of Chemistry, Yasouj University, Yasouj 75918-74831, Iran.
| | - Kheibar Dashtian
- Department of Chemistry, Yasouj University, Yasouj 75918-74831, Iran
| | - Seyed Sajad Khoramrooz
- Cellular and Molecular Research Center, Yasuj University of Medical Sciences, Yasuj, IR, Iran
| | - Leila Manzouri
- Social Determinants of Health Research Center, Yasuj University of Medical Sciences, Yasuj, Iran
| | | | - Vahid Pezeshkpour
- Cellular and Molecular Research Center, Yasuj University of Medical Sciences, Yasuj, IR, Iran; Department of Biotechnology and Microbial Nanotechnology, Dena Pathobiology Laboratory, Yasuj, IR, Iran
| | - Farzad Sadri
- Department of Molecular Microbiology, Dena Pathobiology Laboratory, Yasouj, Iran; Young Researchers and Elite Club, Yasooj Branch, Islamic Azad University, Yasooj, Iran
| | - Marzieh Askarinia
- Cellular and Molecular Research Center, Yasuj University of Medical Sciences, Yasuj, IR, Iran; Student Research Committee, Yasuj University of Medical Sciences, Yasuj, Iran
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16
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Dixit S, Dubey RC, Maheshwari DK, Seth PK, Bajpai VK. Roles of quorum sensing molecules from Rhizobium etli RT1 in bacterial motility and biofilm formation. Braz J Microbiol 2017; 48:815-821. [PMID: 28735852 PMCID: PMC5628318 DOI: 10.1016/j.bjm.2016.08.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 08/31/2016] [Indexed: 01/05/2023] Open
Abstract
Strain RT1 was isolated from root nodules of Lens culinaris (a lentil) and characterized as Rhizobium etli (a Gram-negative soil-borne bacterium) by 16S rDNA sequencing and phylogenetic analysis. The signaling molecules produced by R. etli (RT1) were detected and identified by high-performance liquid chromatography coupled with mass spectrometry. The most abundant and biologically active N-acyl homoserine lactone molecules (3-oxo-C8-HSL and 3-OH-C14-HSL) were detected in the ethyl acetate extract of RT1. The biological role of 3-oxo-C8-HSL was evaluated in RT1. Bacterial motility and biofilm formation were affected or modified on increasing concentrations of 3-oxo-C8-HSL. Results confirmed the existence of cell communication in RT1 mediated by 3-oxo-C8-HSL, and positive correlations were found among quorum sensing, motility and biofilm formation in RT1.
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Affiliation(s)
- Swarnita Dixit
- Department of Botany and Microbiology, Gurukul Kangri University, Haridwar, Uttrakhand, India
| | - Ramesh Chand Dubey
- Department of Botany and Microbiology, Gurukul Kangri University, Haridwar, Uttrakhand, India
| | - Dinesh Kumar Maheshwari
- Department of Botany and Microbiology, Gurukul Kangri University, Haridwar, Uttrakhand, India
| | | | - Vivek K Bajpai
- Department of Applied Microbiology and Biotechnology, School of Biotechnology, Yeungnam University, Gyeongsan, Gyeongbuk, Republic of Korea.
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17
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Abstract
Proteus mirabilis is a Gram-negative bacterium and is well known for its ability to robustly swarm across surfaces in a striking bulls'-eye pattern. Clinically, this organism is most frequently a pathogen of the urinary tract, particularly in patients undergoing long-term catheterization. This review covers P. mirabilis with a focus on urinary tract infections (UTI), including disease models, vaccine development efforts, and clinical perspectives. Flagella-mediated motility, both swimming and swarming, is a central facet of this organism. The regulation of this complex process and its contribution to virulence is discussed, along with the type VI-secretion system-dependent intra-strain competition, which occurs during swarming. P. mirabilis uses a diverse set of virulence factors to access and colonize the host urinary tract, including urease and stone formation, fimbriae and other adhesins, iron and zinc acquisition, proteases and toxins, biofilm formation, and regulation of pathogenesis. While significant advances in this field have been made, challenges remain to combatting complicated UTI and deciphering P. mirabilis pathogenesis.
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18
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Monteiro ACM, Fortaleza CMCB, Ferreira AM, Cavalcante RDS, Mondelli AL, Bagagli E, da Cunha MDLRDS. Comparison of methods for the identification of microorganisms isolated from blood cultures. Ann Clin Microbiol Antimicrob 2016; 15:45. [PMID: 27496125 PMCID: PMC4974807 DOI: 10.1186/s12941-016-0158-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 07/14/2016] [Indexed: 11/12/2022] Open
Abstract
Background Bloodstream infections are responsible for thousands of deaths each year. The rapid identification of the microorganisms causing these infections permits correct therapeutic management that will improve the prognosis of the patient. In an attempt to reduce the time spent on this step, microorganism identification devices have been developed, including the VITEK® 2 system, which is currently used in routine clinical microbiology laboratories. Methods This study evaluated the accuracy of the VITEK® 2 system in the identification of 400 microorganisms isolated from blood cultures and compared the results to those obtained with conventional phenotypic and genotypic methods. In parallel to the phenotypic identification methods, the DNA of these microorganisms was extracted directly from the blood culture bottles for genotypic identification by the polymerase chain reaction (PCR) and DNA sequencing. Results The automated VITEK® 2 system correctly identified 94.7 % (379/400) of the isolates. The YST and GN cards resulted in 100 % correct identifications of yeasts (15/15) and Gram-negative bacilli (165/165), respectively. The GP card correctly identified 92.6 % (199/215) of Gram-positive cocci, while the ANC card was unable to correctly identify any Gram-positive bacilli (0/5). Conclusions The performance of the VITEK® 2 system was considered acceptable and statistical analysis showed that the system is a suitable option for routine clinical microbiology laboratories to identify different microorganisms.
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Affiliation(s)
- Aydir Cecília Marinho Monteiro
- Departamento de Microbiologia e Imunologia, Instituto de Biociências de Botucatu, UNESP-Univ. Estadual Paulista, Distrito de Rubião Junior, s/n, Botucatu, SP, CEP: 18618-970, Brazil
| | - Carlos Magno Castelo Branco Fortaleza
- Departamento de Doenças Tropicais, Faculdade de Medicina de Botucatu, UNESP-Univ. Estadual Paulista, Distrito de Rubião Junior, s/n, Botucatu, SP, CEP: 18618-970, Brazil
| | - Adriano Martison Ferreira
- Laboratório de Análises Clínicas do Hospital das Clínicas de Botucatu, Faculdade de Medicina de Botucatu, UNESP-Univ. Estadual Paulista, Distrito de Rubião Junior, s/n, Botucatu, SP, CEP: 18618-970, Brazil
| | - Ricardo de Souza Cavalcante
- Comissão de Controle de Infecção Relacionada à Assistência à Saúde, Hospital das Clínicas, Faculdade de Medicina de Botucatu, UNESP-Univ. Estadual Paulista, Distrito de Rubião Junior, s/n, Botucatu, SP, CEP: 18618-970, Brazil
| | - Alessandro Lia Mondelli
- Departamento de Clínica Médica, Faculdade de Medicina de Botucatu, UNESP-Univ. Estadual Paulista, Distrito de Rubião Junior, s/n, Botucatu, SP, CEP: 18618-970, Brazil
| | - Eduardo Bagagli
- Departamento de Microbiologia e Imunologia, Instituto de Biociências de Botucatu, UNESP-Univ. Estadual Paulista, Distrito de Rubião Junior, s/n, Botucatu, SP, CEP: 18618-970, Brazil
| | - Maria de Lourdes Ribeiro de Souza da Cunha
- Departamento de Microbiologia e Imunologia, Instituto de Biociências de Botucatu, UNESP-Univ. Estadual Paulista, Distrito de Rubião Junior, s/n, Botucatu, SP, CEP: 18618-970, Brazil. .,Departamento de Doenças Tropicais, Faculdade de Medicina de Botucatu, UNESP-Univ. Estadual Paulista, Distrito de Rubião Junior, s/n, Botucatu, SP, CEP: 18618-970, Brazil.
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19
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Silva LN, Zimmer KR, Macedo AJ, Trentin DS. Plant Natural Products Targeting Bacterial Virulence Factors. Chem Rev 2016; 116:9162-236. [PMID: 27437994 DOI: 10.1021/acs.chemrev.6b00184] [Citation(s) in RCA: 263] [Impact Index Per Article: 32.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Decreased antimicrobial efficiency has become a global public health issue. The paucity of new antibacterial drugs is evident, and the arsenal against infectious diseases needs to be improved urgently. The selection of plants as a source of prototype compounds is appropriate, since plant species naturally produce a wide range of secondary metabolites that act as a chemical line of defense against microorganisms in the environment. Although traditional approaches to combat microbial infections remain effective, targeting microbial virulence rather than survival seems to be an exciting strategy, since the modulation of virulence factors might lead to a milder evolutionary pressure for the development of resistance. Additionally, anti-infective chemotherapies may be successfully achieved by combining antivirulence and conventional antimicrobials, extending the lifespan of these drugs. This review presents an updated discussion of natural compounds isolated from plants with chemically characterized structures and activity against the major bacterial virulence factors: quorum sensing, bacterial biofilms, bacterial motility, bacterial toxins, bacterial pigments, bacterial enzymes, and bacterial surfactants. Moreover, a critical analysis of the most promising virulence factors is presented, highlighting their potential as targets to attenuate bacterial virulence. The ongoing progress in the field of antivirulence therapy may therefore help to translate this promising concept into real intervention strategies in clinical areas.
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Affiliation(s)
- Laura Nunes Silva
- Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul , Porto Alegre, Rio Grande do Sul 90610-000, Brazil.,Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul , Porto Alegre, Rio Grande do Sul 91501-970, Brazil
| | - Karine Rigon Zimmer
- Departamento de Ciências Básicas da Saúde, Universidade Federal de Ciências da Saúde de Porto Alegre , Porto Alegre, Rio Grande do Sul 90050-170, Brazil
| | - Alexandre José Macedo
- Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul , Porto Alegre, Rio Grande do Sul 90610-000, Brazil.,Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul , Porto Alegre, Rio Grande do Sul 91501-970, Brazil.,Instituto Nacional do Semiárido , Campina Grande, Paraı́ba 58429-970, Brazil
| | - Danielle Silva Trentin
- Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul , Porto Alegre, Rio Grande do Sul 90610-000, Brazil.,Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul , Porto Alegre, Rio Grande do Sul 91501-970, Brazil
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20
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The Rcs regulon in Proteus mirabilis: implications for motility, biofilm formation, and virulence. Curr Genet 2016; 62:775-789. [DOI: 10.1007/s00294-016-0579-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 02/05/2016] [Accepted: 02/09/2016] [Indexed: 10/22/2022]
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21
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Harshey RM, Partridge JD. Shelter in a Swarm. J Mol Biol 2015; 427:3683-94. [PMID: 26277623 DOI: 10.1016/j.jmb.2015.07.025] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 07/29/2015] [Accepted: 07/31/2015] [Indexed: 01/04/2023]
Abstract
Flagella propel bacteria during both swimming and swarming, dispersing them widely. However, while swimming bacteria use chemotaxis to find nutrients and avoid toxic environments, swarming bacteria appear to suppress chemotaxis and to use the dynamics of their collective motion to continuously expand and acquire new territory, barrel through lethal chemicals in their path, carry along bacterial and fungal cargo that assists in exploration of new niches, and engage in group warfare for niche dominance. Here, we focus on two aspects of swarming, which, if understood, hold the promise of revealing new insights into microbial signaling and behavior, with ramifications beyond bacterial swarming. These are as follows: how bacteria sense they are on a surface and turn on programs that promote movement and how they override scarcity and adversity as dense packs.
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Affiliation(s)
- Rasika M Harshey
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA.
| | - Jonathan D Partridge
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA
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22
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Regulation of the Min Cell Division Inhibition Complex by the Rcs Phosphorelay in Proteus mirabilis. J Bacteriol 2015; 197:2499-507. [PMID: 25986901 DOI: 10.1128/jb.00094-15] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 05/07/2015] [Indexed: 12/22/2022] Open
Abstract
UNLABELLED A key regulator of swarming in Proteus mirabilis is the Rcs phosphorelay, which represses flhDC, encoding the master flagellar regulator FlhD4C2. Mutants in rcsB, the response regulator in the Rcs phosphorelay, hyperswarm on solid agar and differentiate into swarmer cells in liquid, demonstrating that this system also influences the expression of genes central to differentiation. To gain a further understanding of RcsB-regulated genes involved in swarmer cell differentiation, transcriptome sequencing (RNA-Seq) was used to examine the RcsB regulon. Among the 133 genes identified, minC and minD, encoding cell division inhibitors, were identified as RcsB-activated genes. A third gene, minE, was shown to be part of an operon with minCD. To examine minCDE regulation, the min promoter was identified by 5' rapid amplification of cDNA ends (5'-RACE), and both transcriptional lacZ fusions and quantitative real-time reverse transcriptase (qRT) PCR were used to confirm that the minCDE operon was RcsB activated. Purified RcsB was capable of directly binding the minC promoter region. To determine the role of RcsB-mediated activation of minCDE in swarmer cell differentiation, a polar minC mutation was constructed. This mutant formed minicells during growth in liquid, produced shortened swarmer cells during differentiation, and exhibited decreased swarming motility. IMPORTANCE This work describes the regulation and role of the MinCDE cell division system in P. mirabilis swarming and swarmer cell elongation. Prior to this study, the mechanisms that inhibit cell division and allow swarmer cell elongation were unknown. In addition, this work outlines for the first time the RcsB regulon in P. mirabilis. Taken together, the data presented in this study begin to address how P. mirabilis elongates upon contact with a solid surface.
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23
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Identification of novel factors involved in modulating motility of Salmonella enterica serotype typhimurium. PLoS One 2014. [PMID: 25369209 DOI: 10.1371/journal.pone.0111513.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Salmonella enterica serotype Typhimurium can move through liquid using swimming motility, and across a surface by swarming motility. We generated a library of targeted deletion mutants in Salmonella Typhimurium strain ATCC14028, primarily in genes specific to Salmonella, that we have previously described. In the work presented here, we screened each individual mutant from this library for the ability to move away from the site of inoculation on swimming and swarming motility agar. Mutants in genes previously described as important for motility, such as flgF, motA, cheY are do not move away from the site of inoculation on plates in our screens, validating our approach. Mutants in 130 genes, not previously known to be involved in motility, had altered movement of at least one type, 9 mutants were severely impaired for both types of motility, while 33 mutants appeared defective on swimming motility plates but not swarming motility plates, and 49 mutants had reduced ability to move on swarming agar but not swimming agar. Finally, 39 mutants were determined to be hypermotile in at least one of the types of motility tested. Both mutants that appeared non-motile and hypermotile on plates were assayed for expression levels of FliC and FljB on the bacterial surface and many of them had altered levels of these proteins. The phenotypes we report are the first phenotypes ever assigned to 74 of these open reading frames, as they are annotated as 'hypothetical genes' in the Typhimurium genome.
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24
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Bogomolnaya LM, Aldrich L, Ragoza Y, Talamantes M, Andrews KD, McClelland M, Andrews-Polymenis HL. Identification of novel factors involved in modulating motility of Salmonella enterica serotype typhimurium. PLoS One 2014; 9:e111513. [PMID: 25369209 PMCID: PMC4219756 DOI: 10.1371/journal.pone.0111513] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 09/28/2014] [Indexed: 12/03/2022] Open
Abstract
Salmonella enterica serotype Typhimurium can move through liquid using swimming motility, and across a surface by swarming motility. We generated a library of targeted deletion mutants in Salmonella Typhimurium strain ATCC14028, primarily in genes specific to Salmonella, that we have previously described. In the work presented here, we screened each individual mutant from this library for the ability to move away from the site of inoculation on swimming and swarming motility agar. Mutants in genes previously described as important for motility, such as flgF, motA, cheY are do not move away from the site of inoculation on plates in our screens, validating our approach. Mutants in 130 genes, not previously known to be involved in motility, had altered movement of at least one type, 9 mutants were severely impaired for both types of motility, while 33 mutants appeared defective on swimming motility plates but not swarming motility plates, and 49 mutants had reduced ability to move on swarming agar but not swimming agar. Finally, 39 mutants were determined to be hypermotile in at least one of the types of motility tested. Both mutants that appeared non-motile and hypermotile on plates were assayed for expression levels of FliC and FljB on the bacterial surface and many of them had altered levels of these proteins. The phenotypes we report are the first phenotypes ever assigned to 74 of these open reading frames, as they are annotated as ‘hypothetical genes’ in the Typhimurium genome.
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Affiliation(s)
- Lydia M. Bogomolnaya
- Department of Microbial Pathogenesis and Immunology, College of Medicine, Texas A&M University, Bryan, Texas, United States of America
- Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| | - Lindsay Aldrich
- Department of Microbial Pathogenesis and Immunology, College of Medicine, Texas A&M University, Bryan, Texas, United States of America
| | - Yuri Ragoza
- Department of Microbial Pathogenesis and Immunology, College of Medicine, Texas A&M University, Bryan, Texas, United States of America
| | - Marissa Talamantes
- Department of Microbial Pathogenesis and Immunology, College of Medicine, Texas A&M University, Bryan, Texas, United States of America
| | - Katharine D. Andrews
- Department of Microbial Pathogenesis and Immunology, College of Medicine, Texas A&M University, Bryan, Texas, United States of America
| | - Michael McClelland
- Department of Microbiology and Molecular Genetics, University of California Irvine, Irvine, California, United States of America
| | - Helene L. Andrews-Polymenis
- Department of Microbial Pathogenesis and Immunology, College of Medicine, Texas A&M University, Bryan, Texas, United States of America
- * E-mail:
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25
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Loss of FliL alters Proteus mirabilis surface sensing and temperature-dependent swarming. J Bacteriol 2014; 197:159-73. [PMID: 25331431 DOI: 10.1128/jb.02235-14] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Proteus mirabilis is a dimorphic motile bacterium well known for its flagellum-dependent swarming motility over surfaces. In liquid, P. mirabilis cells are 1.5- to 2.0-μm swimmer cells with 4 to 6 flagella. When P. mirabilis encounters a solid surface, where flagellar rotation is limited, swimmer cells differentiate into elongated (10- to 80-μm), highly flagellated swarmer cells. In order for P. mirabilis to swarm, it first needs to detect a surface. The ubiquitous but functionally enigmatic flagellar basal body protein FliL is involved in P. mirabilis surface sensing. Previous studies have suggested that FliL is essential for swarming through its involvement in viscosity-dependent monitoring of flagellar rotation. In this study, we constructed and characterized ΔfliL mutants of P. mirabilis and Escherichia coli. Unexpectedly and unlike other fliL mutants, both P. mirabilis and E. coli ΔfliL cells swarm (Swr(+)). Further analysis revealed that P. mirabilis ΔfliL cells also exhibit an alteration in their ability to sense a surface: e.g., ΔfliL P. mirabilis cells swarm precociously over surfaces with low viscosity that normally impede wild-type swarming. Precocious swarming is due to an increase in the number of elongated swarmer cells in the population. Loss of fliL also results in an inhibition of swarming at <30°C. E. coli ΔfliL cells also exhibit temperature-sensitive swarming. These results suggest an involvement of FliL in the energetics and function of the flagellar motor.
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26
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Biofilms, flagella, and mechanosensing of surfaces by bacteria. Trends Microbiol 2014; 22:517-27. [DOI: 10.1016/j.tim.2014.05.002] [Citation(s) in RCA: 251] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Revised: 05/06/2014] [Accepted: 05/08/2014] [Indexed: 11/18/2022]
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27
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Armbruster CE, Hodges SA, Smith SN, Alteri CJ, Mobley HLT. Arginine promotes Proteus mirabilis motility and fitness by contributing to conservation of the proton gradient and proton motive force. Microbiologyopen 2014; 3:630-41. [PMID: 25100003 PMCID: PMC4234256 DOI: 10.1002/mbo3.194] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Revised: 06/04/2014] [Accepted: 06/16/2014] [Indexed: 12/22/2022] Open
Abstract
Swarming contributes to Proteus mirabilis pathogenicity by facilitating access to the catheterized urinary tract. We previously demonstrated that 0.1–20 mmol/L arginine promotes swarming on normally nonpermissive media and that putrescine biosynthesis is required for arginine-induced swarming. We also previously determined that arginine-induced swarming is pH dependent, indicating that the external proton concentration is critical for arginine-dependent effects on swarming. In this study, we utilized survival at pH 5 and motility as surrogates for measuring changes in the proton gradient (ΔpH) and proton motive force (μH+) in response to arginine. We determined that arginine primarily contributes to ΔpH (and therefore μH+) through the action of arginine decarboxylase (speA), independent of the role of this enzyme in putrescine biosynthesis. In addition to being required for motility, speA also contributed to fitness during infection. In conclusion, consumption of intracellular protons via arginine decarboxylase is one mechanism used by P. mirabilis to conserve ΔpH and μH+ for motility.
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Affiliation(s)
- Chelsie E Armbruster
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, 48104
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28
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Kuan L, Schaffer JN, Zouzias CD, Pearson MM. Characterization of 17 chaperone-usher fimbriae encoded by Proteus mirabilis reveals strong conservation. J Med Microbiol 2014; 63:911-922. [PMID: 24809384 DOI: 10.1099/jmm.0.069971-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Proteus mirabilis is a Gram-negative enteric bacterium that causes complicated urinary tract infections, particularly in patients with indwelling catheters. Sequencing of clinical isolate P. mirabilis HI4320 revealed the presence of 17 predicted chaperone-usher fimbrial operons. We classified these fimbriae into three groups by their genetic relationship to other chaperone-usher fimbriae. Sixteen of these fimbriae are encoded by all seven currently sequenced P. mirabilis genomes. The predicted protein sequence of the major structural subunit for 14 of these fimbriae was highly conserved (≥ 95% identity), whereas three other structural subunits (Fim3A, UcaA and Fim6A) were variable. Further examination of 58 clinical isolates showed that 14 of the 17 predicted major structural subunit genes of the fimbriae were present in most strains (>85%). Transcription of the predicted major structural subunit genes for all 17 fimbriae was measured under different culture conditions designed to mimic conditions in the urinary tract. The majority of the fimbrial genes were induced during stationary phase, static culture or colony growth when compared to exponential-phase aerated culture. Major structural subunit proteins for six of these fimbriae were detected using MS of proteins sheared from the surface of broth-cultured P. mirabilis, demonstrating that this organism may produce multiple fimbriae within a single culture. The high degree of conservation of P. mirabilis fimbriae stands in contrast to uropathogenic Escherichia coli and Salmonella enterica, which exhibit greater variability in their fimbrial repertoires. These findings suggest there may be evolutionary pressure for P. mirabilis to maintain a large fimbrial arsenal.
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Affiliation(s)
- Lisa Kuan
- Departments of Microbiology and Urology, New York University Medical Center, New York, NY, USA
| | - Jessica N Schaffer
- Departments of Microbiology and Urology, New York University Medical Center, New York, NY, USA
| | - Christos D Zouzias
- Departments of Microbiology and Urology, New York University Medical Center, New York, NY, USA
| | - Melanie M Pearson
- Departments of Microbiology and Urology, New York University Medical Center, New York, NY, USA
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29
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Kalai Chelvam K, Chai LC, Thong KL. Variations in motility and biofilm formation of Salmonella enterica serovar Typhi. Gut Pathog 2014; 6:2. [PMID: 24499680 PMCID: PMC3922113 DOI: 10.1186/1757-4749-6-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2013] [Accepted: 01/28/2014] [Indexed: 01/02/2023] Open
Abstract
Background Salmonella enterica serovar Typhi (S. Typhi) exhibits unique characteristics as an intracellular human pathogen. It causes both acute and chronic infection with various disease manifestations in the human host only. The principal factors underlying the unique lifestyle of motility and biofilm forming ability of S. Typhi remain largely unknown. The main objective of this study was to explore and investigate the motility and biofilm forming behaviour among S. Typhi strains of diverse background. Results Swim and swarm motility tests were performed with 0.25% and 0.5% agar concentration, respectively; while biofilm formation was determined by growing the bacterial cultures for 48 hrs in 96-well microtitre plate. While all S. Typhi strains demonstrated swarming motility with smooth featureless morphology, 58 out of 60 strains demonstrated swimming motility with featureless or bull’s eye morphology. Interestingly, S. Typhi strains of blood-borne origin exhibited significantly higher swimming motility (P < 0.05) than stool-borne strains suggesting that swimming motility may play a role in the systemic invasion of S. Typhi in the human host. Also, stool-borne S. Typhi displayed a negative relationship between motility and biofilm forming behaviour, which was not observed in the blood-borne strains. Conclusion In summary, both swimming and swarming motility are conserved among S. Typhi strains but there was variation for biofilm forming ability. There was no difference observed in this phenotype for S. Typhi strains from diverse background. These findings serve as caveats for future studies to understand the lifestyle and transmission of this pathogen.
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Affiliation(s)
| | | | - Kwai Lin Thong
- Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia.
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Czerwonka G, Arabski M, Wąsik S, Jabłońska-Wawrzycka A, Rogala P, Kaca W. Morphological changes in Proteus mirabilis O18 biofilm under the influence of a urease inhibitor and a homoserine lactone derivative. Arch Microbiol 2014; 196:169-77. [PMID: 24481535 PMCID: PMC3931938 DOI: 10.1007/s00203-014-0952-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Revised: 12/08/2013] [Accepted: 01/04/2014] [Indexed: 01/20/2023]
Abstract
Proteus mirabilis is a pathogenic gram-negative bacterium that frequently causes kidney infections, typically established by ascending colonization of the urinary tract. The present study is focused on ureolytic activity and urease inhibition in biofilms generated by P. mirabilis O18 cells. Confocal microscopy revealed morphological alterations in biofilms treated with urea and a urease inhibitor (acetohydroxamic acid, AHA), as some swarmer cells were found to protrude from the biofilm. The presence of a quorum-sensing molecule (N-butanoyl homoserine lactone, BHL) increased biofilm thickness and its ureolytic activity. Laser interferometric determination of diffusion showed that urea easily diffuses through P. mirabilis biofilm, while AHA is blocked. This may suggest that the use of urease inhibitors in CAUTIs may by less effective than in other urease-associated infections. Spectroscopic studies revealed differences between biofilm and planktonic cells indicating that polysaccharides and nucleic acids are involved in extracellular matrix and biofilm formation.
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Affiliation(s)
- Grzegorz Czerwonka
- Department of Microbiology, Jan Kochanowski University in Kielce, Świętokrzyska 15, 25-406, Kielce, Poland,
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Initiation of swarming motility by Proteus mirabilis occurs in response to specific cues present in urine and requires excess L-glutamine. J Bacteriol 2013; 195:1305-19. [PMID: 23316040 DOI: 10.1128/jb.02136-12] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Proteus mirabilis, a leading cause of catheter-associated urinary tract infection (CaUTI), differentiates into swarm cells that migrate across catheter surfaces and medium solidified with 1.5% agar. While many genes and nutrient requirements involved in the swarming process have been identified, few studies have addressed the signals that promote initiation of swarming following initial contact with a surface. In this study, we show that P. mirabilis CaUTI isolates initiate swarming in response to specific nutrients and environmental cues. Thirty-three compounds, including amino acids, polyamines, fatty acids, and tricarboxylic acid (TCA) cycle intermediates, were tested for the ability to promote swarming when added to normally nonpermissive media. L-Arginine, L-glutamine, DL-histidine, malate, and DL-ornithine promoted swarming on several types of media without enhancing swimming motility or growth rate. Testing of isogenic mutants revealed that swarming in response to the cues required putrescine biosynthesis and pathways involved in amino acid metabolism. Furthermore, excess glutamine was found to be a strict requirement for swarming on normal swarm agar in addition to being a swarming cue under normally nonpermissive conditions. We thus conclude that initiation of swarming occurs in response to specific cues and that manipulating concentrations of key nutrient cues can signal whether or not a particular environment is permissive for swarming.
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Strating H, Vandenende C, Clarke AJ. Changes in peptidoglycan structure and metabolism during differentiation of Proteus mirabilis into swarmer cells. Can J Microbiol 2012; 58:1183-94. [PMID: 23051614 DOI: 10.1139/w2012-102] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The O-acetylation of peptidoglycan in Gram-negative bacteria occurs specifically at the C-6 hydroxyl group of muramoyl residues. The level of peptidoglycan O-acetylation was found to decrease from 51% to 29% upon differentiation of Proteus mirabilis vegetative cells to swarmers. This decrease was accompanied by a change in the muropeptide composition of the peptidoglycan. In particular, the content of anhydromuropeptides increased, while the amount of Lys-Lys-muropeptides arising from bound lipoprotein decreased. These changes together with a shift in proportion of larger muropeptides suggested a decrease in average chain length of the muropeptides from swarmer cells. Zymography using SDS-PAGE gels containing either O-acetylated or chemically de-O-acetylated peptidoglycan was used to monitor the activity of specific autolysins during the differentiation of vegetative to swarming cells of P. mirabilis. A 43 kDa autolysin with increased specificity for O-acetylated peptidoglycan was detected in vegetative cells, but its activity appeared to decrease as the cells began to differentiate, while the levels of 3 other autolysins with apparent specificity for non-O-acetylated peptidoglycan increased. These changes are discussed in relation to the autolysin profile of the bacteria and the changes in peptidoglycan composition with cell differentiation.
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Affiliation(s)
- Hendrik Strating
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada
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Armbruster CE, Mobley HLT. Merging mythology and morphology: the multifaceted lifestyle of Proteus mirabilis. Nat Rev Microbiol 2012; 10:743-54. [PMID: 23042564 DOI: 10.1038/nrmicro2890] [Citation(s) in RCA: 177] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Proteus mirabilis, named for the Greek god who changed shape to avoid capture, has fascinated microbiologists for more than a century with its unique swarming differentiation, Dienes line formation and potent urease activity. Transcriptome profiling during both host infection and swarming motility, coupled with the availability of the complete genome sequence for P. mirabilis, has revealed the occurrence of interbacterial competition and killing through a type VI secretion system, and the reciprocal regulation of adhesion and motility, as well as the intimate connections between metabolism, swarming and virulence. This Review addresses some of the unique and recently described aspects of P. mirabilis biology and pathogenesis, and emphasizes the potential role of this bacterium in single-species and polymicrobial urinary tract infections.
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Affiliation(s)
- Chelsie E Armbruster
- Department of Microbiology and Immunology, University of Michigan Medical School, 1150 West Medical Center Drive, 5641 Medical Science Building II, Ann Arbor, Michigan 48109, USA
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Cysteine catabolism and cysteine desulfhydrase (CdsH/STM0458) in Salmonella enterica serovar typhimurium. J Bacteriol 2012; 194:4366-76. [PMID: 22685283 DOI: 10.1128/jb.00729-12] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Cysteine is potentially toxic and can affect diverse functions such as oxidative stress, antibiotic resistance, and swarming motility. The contribution of cysteine catabolism in modulating responses to cysteine has not been examined, in part because the genes have not been identified and mutants lacking these genes have not been isolated or characterized. We identified the gene for a previously described cysteine desulfhydrase, which we designated cdsH (formerly STM0458). We also identified a divergently transcribed gene that regulates cdsH expression, which we designated cutR (formerly ybaO, or STM0459). CdsH appears to be the major cysteine-degrading and sulfide-producing enzyme aerobically but not anaerobically. Mutants with deletions of cdsH and ybaO exhibited increased sensitivity to cysteine toxicity and altered swarming motility but unaltered cysteine-enhanced antibiotic resistance and survival in macrophages.
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Influence of quorum sensing signal molecules on biofilm formation in Proteus mirabilis O18. Folia Microbiol (Praha) 2011; 57:53-60. [PMID: 22198843 PMCID: PMC3297748 DOI: 10.1007/s12223-011-0091-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Accepted: 12/06/2011] [Indexed: 11/15/2022]
Abstract
The influence of basis of quorum sensing molecules on Proteus strains is much less known as compared to Pseudomonas or Escherichia. We have previously shown that a series of acylated homoserine lactones (acyl-HSL) does not influence the ureolytic, proteolytic, or hemolytic abilities, and that the swarming motility of Proteus mirabilis rods is strain specific. The aim of the presented study was to find out if the presence of a series of acyl-HSL influences biofilm formation of P. mirabilis laboratory strain belonging to O18 serogroup. This serogroup is characterized by the presence of a unique non-carbohydrate component, namely phosphocholine. Escherichia coli and P. mirabilis O18 strains used in this work contains cloned plasmids encoding fluorescent protein genes with constitutive gene expression. In mixed biofilms in stationary and continuous flow conditions, P. mirabilis O18 overgrow whole culture. P. mirabilis O18 strain has genetically proved a presence of AI–2 quorum sensing system. Differences in biofilm structure were observed depending on the biofilm type and culture methods. From tested acylated homoserine lactones (BHL, HHL, OHL, DHL, dDHL, tDHL), a significant influence had BHL on thickness, structure, and the amount of exopolysaccharides produced by biofilms formed by P. mirabilis O18 pDsRed2.
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Role of the Umo proteins and the Rcs phosphorelay in the swarming motility of the wild type and an O-antigen (waaL) mutant of Proteus mirabilis. J Bacteriol 2011; 194:669-76. [PMID: 22139504 DOI: 10.1128/jb.06047-11] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Proteus mirabilis is a Gram-negative bacterium that exists as a short rod when grown in liquid medium, but during growth on surfaces it undergoes a distinct physical and biochemical change that culminates in the formation of a swarmer cell. How P. mirabilis senses a surface is not fully understood; however, the inhibition of flagellar rotation and accumulation of putrescine have been proposed to be sensory mechanisms. Our lab recently isolated a transposon insertion in waaL, encoding O-antigen ligase, that resulted in a loss of swarming but not swimming motility. The waaL mutant failed to activate flhDC, the class 1 activator of the flagellar gene cascade, when grown on solid surfaces. Swarming in the waaL mutant was restored by overexpression of flhDC in trans or by a mutation in the response regulator rcsB. To further investigate the role of the Rcs signal transduction pathway and its possible relationship with O-antigen surface sensing, mutations were made in the rcsC, rcsB, rcsF, umoB (igaA), and umoD genes in wild-type and waaL backgrounds. Comparison of the swarming phenotypes of the single and double mutants and of strains overexpressing combinations of the UmoB, UmoD, and RcsF proteins demonstrated the following: (i) there is a differential effect of RcsF and UmoB on swarming in wild-type and waaL backgrounds, (ii) RcsF inhibits UmoB activity but not UmoD activity in a wild-type background, and (iii) UmoD is able to modulate activity of the Rcs system.
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37
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Patrick JE, Kearns DB. Swarming motility and the control of master regulators of flagellar biosynthesis. Mol Microbiol 2011; 83:14-23. [PMID: 22092493 DOI: 10.1111/j.1365-2958.2011.07917.x] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Swarming motility is the movement of bacteria over a solid surface powered by rotating flagella. The expression of flagellar biosynthesis genes is governed by species-specific master regulator transcription factors. Mutations that reduce or enhance master regulator activity have a commensurate effect on swarming motility. Here we review what is known about the proteins that modulate swarming motility and appear to act upstream of the master flagellar regulators in diverse swarming bacteria. We hypothesize that environmental control of the master regulators is important to the swarming phenotype perhaps at the level of controlling flagellar number.
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Affiliation(s)
- Joyce E Patrick
- Indiana University, Department of Biology, 1001 East Third Street, Bloomington, IN 47405, USA
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38
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Perturbation of FliL interferes with Proteus mirabilis swarmer cell gene expression and differentiation. J Bacteriol 2011; 194:437-47. [PMID: 22081397 DOI: 10.1128/jb.05998-11] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Proteus mirabilis is a dimorphic, motile bacterium often associated with urinary tract infections. Colonization of urinary tract surfaces is aided by swarmer cell differentiation, which is initiated by inhibition of flagellar rotation when the bacteria first contact a surface. Mutations in fliL, encoding a flagellar structural protein with an enigmatic function, result in the inappropriate production of differentiated swarmer cells, called pseudoswarmer cells, under noninducing conditions, indicating involvement of FliL in the surface sensing pathway. In the present study, we compared the fliL transcriptome with that of wild-type swarmer cells and showed that nearly all genes associated with motility (flagellar class II and III genes) and chemotaxis are repressed. In contrast, spontaneous motile revertants of fliL cells that regained motility yet produced differentiated swarmer cells under noninducing conditions transcribed flagellar class II promoters at consistent levels. Expression of umoA (a known regulator of swarmer cells), flgF, and flgI increased significantly in both swarmer and pseudoswarmer cells, as did genes in a degenerate prophage region situated immediately adjacent to the Rcs phosphorelay system. Unlike swarmer cells, pseudoswarmers displayed increased activity, rather than transcription, of the flagellar master regulatory protein, FlhD(4)C(2), and analyses of the fliL parent strain and its motile revertants showed that they result from mutations altering the C-terminal 14 amino acids of FliL. Collectively, the data suggest a functional role for the C terminus of FliL in surface sensing and implicate UmoA as part of the signal relay leading to the master flagellar regulator FlhD(4)C(2), which ultimately controls swarmer cell differentiation.
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Abstract
How bacteria regulate, assemble and rotate flagella to swim in liquid media is reasonably well understood. Much less is known about how some bacteria use flagella to move over the tops of solid surfaces in a form of movement called swarming. The focus of bacteriology is changing from planktonic to surface environments, and so interest in swarming motility is on the rise. Here, I review the requirements that define swarming motility in diverse bacterial model systems, including an increase in the number of flagella per cell, the secretion of a surfactant to reduce surface tension and allow spreading, and movement in multicellular groups rather than as individuals.
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40
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Clarke DJ. The Rcs phosphorelay: more than just a two-component pathway. Future Microbiol 2010; 5:1173-84. [DOI: 10.2217/fmb.10.83] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The Rcs phosphorelay is a complex signaling pathway found in many, but not all, members of the Enterobacteriaceae. The complexity of this pathway is due to the direct involvement of three proteins (RcsC, RcsD and RcsB) in the phosphorelay and the presence of multiple accessory proteins with important roles in modulating the inputs and outputs associated with this signaling pathway. This article will discuss the various inputs and outputs associated with the Rcs phosphorelay and also present a model suggesting an important role for this signaling pathway in the temporal control of virulence in Salmonella enterica and biofilm formation in Escherichia coli.
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Affiliation(s)
- David J Clarke
- Department of Microbiology & Alimentary Pharmabiotic Centre, University College Cork, Ireland
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Morgenstein RM, Szostek B, Rather PN. Regulation of gene expression during swarmer cell differentiation in Proteus mirabilis. FEMS Microbiol Rev 2010; 34:753-63. [PMID: 20497230 DOI: 10.1111/j.1574-6976.2010.00229.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The gram-negative bacterium Proteus mirabilis can exist in either of two cell types, a vegetative cell characterized as a short rod and a highly elongated and hyperflagellated swarmer cell. This differentiation is triggered by growth on solid surfaces and multiple inputs are sensed by the cell to initiate the differentiation process. These include the inhibition of flagellar rotation, the accumulation of extracellular putrescine and O-antigen interactions with a surface. A key event in the differentiation process is the upregulation of FlhD(2)C(2), which activates the flagellar regulon and additional genes required for differentiation. There are a number of genes that influence FlhD(2)C(2) expression and the function of these genes, if known, will be discussed in this review. Additional genes that have been shown to regulate gene expression during swarming will also be reviewed. Although P. mirabilis represents an excellent system to study microbial differentiation, it is largely understudied relative to other systems. Therefore, this review will also discuss some of the unanswered questions that are central to understanding this process in P. mirabilis.
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Affiliation(s)
- Randy M Morgenstein
- Department of Microbiology and Immunology, 3001 Rollins Research Center, Emory University, Atlanta, GA 30322, USA
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Loss of the waaL O-antigen ligase prevents surface activation of the flagellar gene cascade in Proteus mirabilis. J Bacteriol 2010; 192:3213-21. [PMID: 20382766 DOI: 10.1128/jb.00196-10] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Proteus mirabilis is a Gram-negative bacterium that undergoes a physical and biochemical change from a vegetative swimmer cell (a typical Gram-negative rod) to an elongated swarmer cell when grown on a solid surface. In this study, we report that a transposon insertion in the waaL gene, encoding O-antigen ligase, blocked swarming motility on solid surfaces but had little effect on swimming motility in soft agar. The waaL mutant was unable to differentiate into a swarmer cell. Differentiation was also prevented by a mutation in wzz, encoding a chain length determinant for O antigen, but not by a mutation in wzyE, encoding an enzyme that polymerizes enterobacterial common antigen, a surface polysaccharide different from the lipid A::core. In wild-type P. mirabilis, increased expression of the flhDC operon occurs after growth on solid surfaces and is required for the high-level expression of flagellin that is characteristic of swarmer cells. However, in both the waaL and the wzz mutants, the flhDC operon was not activated during growth on agar. A loss-of-function mutation in the rcsB response regulator or overexpression of flhDC restored swarming to the waaL mutant, despite the absence of O antigen. Therefore, although O antigen may serve a role in swarming by promoting wettability, the loss of O antigen blocks a regulatory pathway that links surface contact with the upregulation of flhDC expression.
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Abstract
Swarming motility by the urinary tract pathogen Proteus mirabilis has been a long-studied but little understood phenomenon. On agar, a P. mirabilis colony grows outward in a bull's-eye pattern formed by consecutive waves of rapid swarming followed by consolidation into shorter cells. To examine differential gene expression in these growth phases, a microarray was constructed based on the completed genome sequence and annotation. RNA was extracted from broth-cultured, swarming, and consolidation-phase cells to assess transcription during each of these growth states. A total of 587 genes were differentially expressed in broth-cultured cells versus swarming cells, and 527 genes were differentially expressed in broth-cultured cells versus consolidation-phase cells (consolidate). Flagellar genes were highly upregulated in both swarming cells and consolidation-phase cells. Fimbriae were downregulated in swarming cells, while genes involved in cell division and anaerobic growth were upregulated in broth-cultured cells. Direct comparison of swarming cells to consolidation-phase cells found that 541 genes were upregulated in consolidate, but only nine genes were upregulated in swarm cells. Genes involved in flagellar biosynthesis, oligopeptide transport, amino acid import and metabolism, cell division, and phage were upregulated in consolidate. Mutation of dppA, oppB, and cysJ, upregulated during consolidation compared to during swarming, revealed that although these genes play a minor role in swarming, dppA and cysJ are required during ascending urinary tract infection. Swarming on agar to which chloramphenicol had been added suggested that protein synthesis is not required for swarming. These data suggest that the consolidation phase is a state in which P. mirabilis prepares for the next wave of swarming.
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Characterization of UDP-glucose dehydrogenase and UDP-glucose pyrophosphorylase mutants of Proteus mirabilis: defectiveness in polymyxin B resistance, swarming, and virulence. Antimicrob Agents Chemother 2010; 54:2000-9. [PMID: 20160049 DOI: 10.1128/aac.01384-09] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Proteus mirabilis is known to be highly resistant to the action of polymyxin B (PB). However, the mechanism underlying PB resistance is not clear. In this study, we used Tn5 transposon mutagenesis to identify genes that may affect PB resistance in P. mirabilis. Two genes, ugd and galU, which may encode UDP-glucose dehydrogenase (Ugd) and UDP-glucose pyrophosphorylase (GalU), respectively, were identified. Knockout mutants of ugd and galU were found to be extremely sensitive to PB, presumably because of alterations in lipopolysaccharide (LPS) structure and cell surface architecture in these mutants. These mutants were defective in swarming, expressed lower levels of virulence factor hemolysin, and had lower cell invasion ability. Complementation of the ugd or galU mutant with the full-length ugd or galU gene, respectively, led to the restoration of wild-type phenotypic traits. Interestingly, we found that the expression of Ugd and GalU was induced by PB through RppA, a putative response regulator of the bacterial two-component system that we identified previously. Mutation in either ugd or galU led to activation of RpoE, an extracytoplasmic function sigma factor that has been shown to be activated by protein misfolding and alterations in cell surface structure in other bacteria. Activation of RpoE or RpoE overexpression was found to cause inhibition of FlhDC and hemolysin expression. To our knowledge, this is the first report describing the roles and regulation of Ugd and GalU in P. mirabilis.
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Regulation of igaA and the Rcs system by the MviA response regulator in Salmonella enterica. J Bacteriol 2009; 191:2743-52. [PMID: 19218385 DOI: 10.1128/jb.01519-08] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
IgaA is a membrane protein that prevents overactivation of the Rcs regulatory system in enteric bacteria. Here we provide evidence that igaA is the first gene in a sigma(70)-dependent operon of Salmonella enterica serovar Typhimurium that also includes yrfG, yrfH, and yrfI. We also show that the Lon protease and the MviA response regulator participate in regulation of the igaA operon. Our results indicate that MviA regulates igaA transcription in an RpoS-dependent manner, but the results also suggest that MviA may regulate RcsB activation in an RpoS- and IgaA-independent manner.
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Abstract
Many bacteria can rapidly traverse surfaces from which they are extracting nutrient for growth. They generate flat, spreading colonies, called swarms because they resemble swarms of insects. We seek to understand how members of any dense swarm spread efficiently while being able to perceive and interfere minimally with the motion of others. To this end, we investigate swarms of the myxobacterium, Myxococcus xanthus. Individual M. xanthus cells are elongated; they always move in the direction of their long axis; and they are in constant motion, repeatedly touching each other. Remarkably, they regularly reverse their gliding directions. We have constructed a detailed cell- and behavior-based computational model of M. xanthus swarming that allows the organization of cells to be computed. By using the model, we are able to show that reversals of gliding direction are essential for swarming and that reversals increase the outflow of cells across the edge of the swarm. Cells at the swarm edge gain maximum exposure to nutrient and oxygen. We also find that the reversal period predicted to maximize the outflow of cells is the same (within the errors of measurement) as the period observed in experiments with normal M. xanthus cells. This coincidence suggests that the circuit regulating reversals evolved to its current sensitivity under selection for growth achieved by swarming. Finally, we observe that, with time, reversals increase the cell alignment, and generate clusters of parallel cells.
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Copeland MF, Weibel DB. Bacterial Swarming: A Model System for Studying Dynamic Self-assembly. SOFT MATTER 2009; 5:1174-1187. [PMID: 23926448 PMCID: PMC3733279 DOI: 10.1039/b812146j] [Citation(s) in RCA: 150] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Bacterial swarming is an example of dynamic self-assembly in microbiology in which the collective interaction of a population of bacterial cells leads to emergent behavior. Swarming occurs when cells interact with surfaces, reprogram their physiology and behavior, and adapt to changes in their environment by coordinating their growth and motility with other cells in the colony. This review summarizes the salient biological and biophysical features of this system and describes our current understanding of swarming motility. We have organized this review into four sections: 1) The biophysics and mechanisms of bacterial motility in fluids and its relevance to swarming. 2) The role of cell/molecule, cell/surface, and cell/cell interactions during swarming. 3) The changes in physiology and behavior that accompany swarming motility. 4) A concluding discussion of several interesting, unanswered questions that is particularly relevant to soft matter scientists.
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Affiliation(s)
- Matthew F. Copeland
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI, U.S.A
| | - Douglas B. Weibel
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI, U.S.A
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48
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Modulation of the Rcs-mediated signal transfer by conformational flexibility. Biochem Soc Trans 2008; 36:1427-32. [DOI: 10.1042/bst0361427] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The Rcs (regulator of capsule synthesis) signalling complex comprises the membrane-associated hybrid sensor kinases RcsC and RcsD, the transcriptional regulator RcsB and the two co-inducers RcsA and RcsF. Acting as a global regulatory network, the Rcs phosphorelay controls multiple cellular pathways including capsule synthesis, cell division, motility, biofilm formation and virulence mechanisms. Signal-dependent communication of the individual Rcs domains showing histidine kinase, phosphoreceiver, phosphoryl transfer and DNA-binding activities is characteristic and essential for the modulation of signal transfer. We have analysed the structures of core elements of the Rcs network including the RcsC-PR (phosphoreceiver domain of RcsC) and the RcsD-HPt (histidine phosphotransfer domain of RcsD), and we have started to characterize the dynamics and recognition mechanisms of the proteins. RcsC-PR represents a typical CheY-like α/β/α sandwich fold and it shows a large conformational flexibility near the active-site residue Asp875. NMR analysis revealed that RcsC-PR is able to adopt preferred conformations upon Mg2+ co-ordination, BeF3− activation, phosphate binding and RcsD-HPt recognition. In contrast, the α-helical structure of RcsD-HPt is conformationally stable and contains a recognition area in close vicinity to the active-site His842 residue. Our studies indicate the importance of protein dynamics and conformational exchange for the differential response to the variety of signals perceived by complex regulatory networks.
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Himpsl SD, Lockatell CV, Hebel JR, Johnson DE, Mobley HLT. Identification of virulence determinants in uropathogenic Proteus mirabilis using signature-tagged mutagenesis. J Med Microbiol 2008; 57:1068-1078. [PMID: 18719175 DOI: 10.1099/jmm.0.2008/002071-0] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
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.
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Affiliation(s)
- Stephanie D Himpsl
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - C Virginia Lockatell
- Division of Infectious Diseases, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - J Richard Hebel
- Department of Epidemiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - David E Johnson
- Research Service, Department of Veteran Affairs, Baltimore, MD 21201, USA.,Division of Infectious Diseases, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Harry L T Mobley
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
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Verstraeten N, Braeken K, Debkumari B, Fauvart M, Fransaer J, Vermant J, Michiels J. Living on a surface: swarming and biofilm formation. Trends Microbiol 2008; 16:496-506. [PMID: 18775660 DOI: 10.1016/j.tim.2008.07.004] [Citation(s) in RCA: 303] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2008] [Revised: 07/16/2008] [Accepted: 07/28/2008] [Indexed: 10/21/2022]
Abstract
Swarming is the fastest known bacterial mode of surface translocation and enables the rapid colonization of a nutrient-rich environment and host tissues. This complex multicellular behavior requires the integration of chemical and physical signals, which leads to the physiological and morphological differentiation of the bacteria into swarmer cells. Here, we provide a review of recent advances in the study of the regulatory pathways that lead to swarming behavior of different model bacteria. It has now become clear that many of these pathways also affect the formation of biofilms, surface-attached bacterial colonies. Decision-making between rapidly colonizing a surface and biofilm formation is central to bacterial survival among competitors. In the second part of this article, we review recent developments in the understanding of the transition between motile and sessile lifestyles of bacteria.
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Affiliation(s)
- Natalie Verstraeten
- Centre of Microbial and Plant Genetics, Katholieke Universiteit Leuven, Kasteelpark Arenberg 20, B-3001 Heverlee, Belgium
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