101
|
Jin C, Vachier J, Bandyopadhyay S, Macharashvili T, Maass CC. Fine balance of chemotactic and hydrodynamic torques: When microswimmers orbit a pillar just once. Phys Rev E 2019; 100:040601. [PMID: 31770913 DOI: 10.1103/physreve.100.040601] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Indexed: 11/07/2022]
Abstract
We study the detention statistics of self-propelling droplet microswimmers attaching to microfluidic pillars. These droplets show negative autochemotaxis: they shed a persistent repulsive trail of spent fuel that biases them to detach from pillars in a specific size range after orbiting them just once. We have designed a microfluidic assay recording microswimmers in pillar arrays of varying diameter, derived detention statistics via digital image analysis, and interpreted these statistics via the Langevin dynamics of an active Brownian particle model. By comparing data from orbits with and without residual chemical field, we can independently estimate quantities such as hydrodynamic and chemorepulsive torques, chemical coupling constants and diffusion coefficients, as well as their dependence on environmental factors such as wall curvature. This type of analysis is generalizable to many kinds of microswimmers.
Collapse
Affiliation(s)
- Chenyu Jin
- Max Planck Institute for Dynamics and Self-Organization, Am Faßberg 17, 37077 Göttingen, Germany
| | - Jérémy Vachier
- Max Planck Institute for Dynamics and Self-Organization, Am Faßberg 17, 37077 Göttingen, Germany
| | - Soumya Bandyopadhyay
- School of Mechanical Engineering, Purdue University, West Lafayette, Indiana 47907, USA
| | | | - Corinna C Maass
- Max Planck Institute for Dynamics and Self-Organization, Am Faßberg 17, 37077 Göttingen, Germany
| |
Collapse
|
102
|
Khan F, Pham DTN, Oloketuyi SF, Kim YM. Regulation and controlling the motility properties of Pseudomonas aeruginosa. Appl Microbiol Biotechnol 2019; 104:33-49. [DOI: 10.1007/s00253-019-10201-w] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 10/07/2019] [Accepted: 10/19/2019] [Indexed: 12/13/2022]
|
103
|
Wang C, Chen W, Xia A, Zhang R, Huang Y, Yang S, Ni L, Jin F. Carbon Starvation Induces the Expression of PprB-Regulated Genes in Pseudomonas aeruginosa. Appl Environ Microbiol 2019; 85:e01705-19. [PMID: 31492668 PMCID: PMC6821963 DOI: 10.1128/aem.01705-19] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 09/02/2019] [Indexed: 01/02/2023] Open
Abstract
Pseudomonas aeruginosa can cause severe infections in humans. This bacterium often adopts a biofilm lifestyle that is hard to treat. In several previous studies, the PprA-PprB two-component system (TCS), which controls the expression of type IVb pili, BapA adhesin, and CupE fimbriae, was shown to be involved in biofilm formation (M. Romero, H. Silistre, L. Lovelock, V. J. Wright, K.-G. Chan, et al., Nucleic Acids Res 46:6823-6840, 2018, https://doi.org/10.1093/nar/gky324; S. de Bentzmann, C. Giraud, C. S. Bernard, V. Calderon, F. Ewald F, et al., PLoS Pathog 8:e1003052, 2012, https://doi.org/10.1371/journal.ppat.1003052). However, signals or environmental conditions that can trigger the PprA-PprB TCS are still unknown, and the molecular mechanisms of PprB-mediated biofilm formation are poorly characterized. Here, we report that carbon starvation stress (CSS) can induce the expression of pprB and genes in the PprB regulon. CSS-induced pprB transcription is mediated by the stress response sigma factor RpoS rather than the two-component sensor PprA. We also observed a strong negative regulation of PprB on the transcription of itself. Further experiments showed that PprB overexpression greatly enhanced cell-cell adhesion (CCA) and cell-surface adhesion (CSA) in P. aeruginosa Specifically, under the background of PprB overexpression, both the BapA adhesin and CupE fimbriae displayed positive effects on CCA and CSA, while the type IVb pili showed an unexpected negative effect on CCA and no effect on CSA. In addition, expression of the PprB regulon genes were significantly increased in 3-day colony biofilms, indicating a possible carbon limitation state. The CSS-RpoS-PprB-Bap/Flp/CupE pathway identified in this study provides a new perspective on the process of biofilm formation in carbon-limited environments.IMPORTANCE Typically, the determination of the external signals that can trigger a regulatory system is crucial to understand the regulatory logic and inward function of that system. The PprA-PprB two-component system was reported to be involved in biofilm formation in Pseudomonas aeruginosa, but the signals triggering this system are unknown. In this study, we found that carbon starvation stress (CSS) induces transcription of pprB and genes in the PprB regulon through an RpoS-dependent pathway. Increased PprB expression leads to enhanced cell-cell adhesion (CCA) and cell-surface adhesion (CSA) in P. aeruginosa Both CCA and CSA are largely dependent on the Bap secretion system and are moderately dependent on the CupE fimbriae. Our findings suggest that PprB reinforces the structure of biofilms under carbon-limited conditions, and the Bap secretion system and CupE fimbriae are two potential targets for biofilm treatment.
Collapse
Affiliation(s)
- Congcong Wang
- Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui, People's Republic of China
| | - Wenhui Chen
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui, People's Republic of China
| | - Aiguo Xia
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui, People's Republic of China
- CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, People's Republic of China
| | - Rongrong Zhang
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui, People's Republic of China
- CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, People's Republic of China
| | - Yajia Huang
- CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, People's Republic of China
| | - Shuai Yang
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui, People's Republic of China
- CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, People's Republic of China
| | - Lei Ni
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui, People's Republic of China
- CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, People's Republic of China
| | - Fan Jin
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui, People's Republic of China
- CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, People's Republic of China
| |
Collapse
|
104
|
Emergent Properties in Streptococcus mutans Biofilms Are Controlled through Adhesion Force Sensing by Initial Colonizers. mBio 2019; 10:mBio.01908-19. [PMID: 31506311 PMCID: PMC6737243 DOI: 10.1128/mbio.01908-19] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Bacterial adhesion is accompanied by altered gene expression, leading to "emergent" properties of biofilm bacteria that are alien to planktonic ones. With the aim of revealing the role of environmental adhesion forces in emergent biofilm properties, genes in Streptococcus mutans UA159 and a quorum-sensing-deficient mutant were identified that become expressed after adhesion to substratum surfaces. Using atomic force microscopy, adhesion forces of initial S. mutans colonizers on four different substrata were determined and related to gene expression. Adhesion forces upon initial contact were similarly low across different substrata, ranging between 0.2 and 1.2 nN regardless of the strain considered. Bond maturation required up to 21 s, depending on the strain and substratum surface involved, but stationary adhesion forces also were similar in the parent and in the mutant strain. However, stationary adhesion forces were largest on hydrophobic silicone rubber (19 to 20 nN), while being smallest on hydrophilic glass (3 to 4 nN). brpA gene expression in thin (34 to 48 μm) 5-h S. mutans UA159 biofilms was most sensitive to adhesion forces, while expression of gbpB and comDE expressions was weakly sensitive. ftf, gtfB, vicR, and relA expression was insensitive to adhesion forces. In thicker (98 to 151 μm) 24-h biofilms, adhesion-force-induced gene expression and emergent extracellular polymeric substance (EPS) production were limited to the first 20 to 30 μm above a substratum surface. In the quorum-sensing-deficient S. mutans, adhesion-force-controlled gene expression was absent in both 5- and 24-h biofilms. Thus, initial colonizers of substratum surfaces sense adhesion forces that externally trigger emergent biofilm properties over a limited distance above a substratum surface through quorum sensing.IMPORTANCE A new concept in biofilm science is introduced: "adhesion force sensitivity of genes," defining the degree up to which expression of different genes in adhering bacteria is controlled by the environmental adhesion forces they experience. Analysis of gene expression as a function of height in a biofilm showed that the information about the substratum surface to which initially adhering bacteria adhere is passed up to a biofilm height of 20 to 30 μm above a substratum surface, highlighting the importance and limitations of cell-to-cell communication in a biofilm. Bacteria in a biofilm mode of growth, as opposed to planktonic growth, are responsible for the great majority of human infections, predicted to become the number one cause of death in 2050. The concept of adhesion force sensitivity of genes provides better understanding of bacterial adaptation in biofilms, direly needed for the design of improved therapeutic measures that evade the recalcitrance of biofilm bacteria to antimicrobials.
Collapse
|
105
|
de Oliveira AB, Ferrisse TM, Marques RS, de Annunzio SR, Brighenti FL, Fontana CR. Effect of Photodynamic Therapy on Microorganisms Responsible for Dental Caries: A Systematic Review and Meta-Analysis. Int J Mol Sci 2019; 20:ijms20143585. [PMID: 31340425 PMCID: PMC6678311 DOI: 10.3390/ijms20143585] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 06/24/2019] [Accepted: 06/25/2019] [Indexed: 12/21/2022] Open
Abstract
The aim of this study was to perform a systematic review of the literature followed by a meta-analysis about the efficacy of photodynamic therapy (PDT) on the microorganisms responsible for dental caries. The research question and the keywords were constructed according to the PICO strategy. The article search was done in Embase, Lilacs, Scielo, Medline, Scopus, Cochrane Library, Web of Science, Science Direct, and Pubmed databases. Randomized clinical trials and in vitro studies were selected in the review. The study was conducted according the PRISMA guideline for systematic review. A total of 34 articles were included in the qualitative analysis and four articles were divided into two subgroups to perform the meta-analysis. Few studies have achieved an effective microbial reduction in microorganisms associated with the pathogenesis of dental caries. The results highlight that there is no consensus about the study protocols for PDT against cariogenic microorganisms, although the results showed the PDT could be a good alternative for the treatment of dental caries.
Collapse
Affiliation(s)
- Analú Barros de Oliveira
- São Paulo State University (UNESP), School of Dentistry, Araraquara, São Paulo 14801-903, Brazil
| | - Túlio Morandin Ferrisse
- São Paulo State University (UNESP), School of Dentistry, Araraquara, São Paulo 14801-903, Brazil
| | - Raquel Souza Marques
- São Paulo State University (UNESP), School of Dentistry, Araraquara, São Paulo 14801-903, Brazil
| | - Sarah Raquel de Annunzio
- São Paulo State University (UNESP), School of Pharmaceutical Sciences, Araraquara, São Paulo 14800-903, Brazil
| | | | - Carla Raquel Fontana
- São Paulo State University (UNESP), School of Pharmaceutical Sciences, Araraquara, São Paulo 14800-903, Brazil.
| |
Collapse
|
106
|
Issa R, Chanishvili N, Caplin J, Kakabadze E, Bakuradze N, Makalatia K, Cooper I. Antibiofilm potential of purified environmental bacteriophage preparations against early stage Pseudomonas aeruginosa biofilms. J Appl Microbiol 2019; 126:1657-1667. [PMID: 30825355 DOI: 10.1111/jam.14241] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 01/30/2019] [Accepted: 02/13/2019] [Indexed: 12/17/2022]
Abstract
AIMS This paper presents the potential of environmentally sourced bacteriophages to affect the growth of clinical isolates of Pseudomonas aeruginosa biofilms, and assesses the respective plaque morphotypes presented by each bacteriophage, in vitro. METHODS AND RESULTS Bacterial host strains were typed for their ability to produce the quorum sensing-controlled virulence factor pyocyanin, and then tested for bacteriophage susceptibility using the spot test method. The bacteriophages were co-administered with ciprofloxacin in order to determine whether the bacteriophages would demonstrate synergistic or antagonistic behaviour to the antibiotic in vitro. Results suggest a potential relationship between the bacteriophage plaque size and biofilm inhibition, where those producing smaller plaques appear to be more effective at reducing bacterial biofilm formation. CONCLUSIONS This phenomenon may be explained by a high adsorption rate leading to the rapid formation of smaller plaques, and greater biofilm reduction associated with the loss of viable bacterial cells before the cells can adhere to the surface and form a biofilm. Results from the co-administration of bacteriophage and ciprofloxacin suggest that the two work synergistically to affect P. aeruginosa biofilms. SIGNIFICANCE AND IMPACT OF THE STUDY The data indicate enhanced efficacy of ciprofloxacin by ≥50%. This could offer an alternative strategy for targeting antibiotic-resistant infections.
Collapse
Affiliation(s)
- R Issa
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, UK
| | - N Chanishvili
- George Eliava Institute of Bacteriophage, Microbiology and Virology, Tbilisi, Georgia
| | - J Caplin
- School of Environment and Technology, University of Brighton, Brighton, UK
| | - E Kakabadze
- George Eliava Institute of Bacteriophage, Microbiology and Virology, Tbilisi, Georgia
| | - N Bakuradze
- George Eliava Institute of Bacteriophage, Microbiology and Virology, Tbilisi, Georgia
| | - K Makalatia
- George Eliava Institute of Bacteriophage, Microbiology and Virology, Tbilisi, Georgia
| | - I Cooper
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, UK
| |
Collapse
|
107
|
Dynamics of cheater invasion in a cooperating population of Pseudomonas aeruginosa. Sci Rep 2019; 9:10190. [PMID: 31308401 PMCID: PMC6629668 DOI: 10.1038/s41598-019-46651-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 06/27/2019] [Indexed: 11/17/2022] Open
Abstract
Pseudomonas aeruginosa quorum sensing (QS) regulates expression of dozens of genes in a cell density-dependent manner. Many QS-regulated genes code for production of extracellular factors, “public goods” that can benefit the entire population. This cooperation encourages individuals to cheat by using but not producing public goods. QS also controls expression of a limited number of genes encoding “private” cellular enzymes like Nuh, an enzyme involved in adenosine catabolism. Growth of P. aeruginosa on casein requires QS-regulated production of an extracellular protease and is an example of cooperative behavior. When P. aeruginosa is transferred daily on casein, QS mutants emerge. These cheaters have mutations in lasR, which encodes the primary QS transcription factor. When growth is on casein and adenosine, cheater emergence is constrained. Here, we report the dynamics of LasR mutant invasion during growth on casein or casein plus adenosine. We show that LasR mutants have the greatest advantage during early to mid-logarithmic growth on casein. Addition of adenosine to casein medium constrains cheaters throughout growth. Our data support the view that co-regulation of the public protease and the private nucleosidase by QS stabilizes cooperation, and the data are not consistent with other proposed alternate hypotheses.
Collapse
|
108
|
Armbruster CR, Lee CK, Parker-Gilham J, de Anda J, Xia A, Zhao K, Murakami K, Tseng BS, Hoffman LR, Jin F, Harwood CS, Wong GCL, Parsek MR. Heterogeneity in surface sensing suggests a division of labor in Pseudomonas aeruginosa populations. eLife 2019; 8:e45084. [PMID: 31180327 PMCID: PMC6615863 DOI: 10.7554/elife.45084] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 06/08/2019] [Indexed: 12/27/2022] Open
Abstract
The second messenger signaling molecule cyclic diguanylate monophosphate (c-di-GMP) drives the transition between planktonic and biofilm growth in many bacterial species. Pseudomonas aeruginosa has two surface sensing systems that produce c-di-GMP in response to surface adherence. Current thinking in the field is that once cells attach to a surface, they uniformly respond by producing c-di-GMP. Here, we describe how the Wsp system generates heterogeneity in surface sensing, resulting in two physiologically distinct subpopulations of cells. One subpopulation has elevated c-di-GMP and produces biofilm matrix, serving as the founders of initial microcolonies. The other subpopulation has low c-di-GMP and engages in surface motility, allowing for exploration of the surface. We also show that this heterogeneity strongly correlates to surface behavior for descendent cells. Together, our results suggest that after surface attachment, P. aeruginosa engages in a division of labor that persists across generations, accelerating early biofilm formation and surface exploration.
Collapse
Affiliation(s)
| | - Calvin K Lee
- Department of BioengineeringUniversity of California, Los AngelesLos AngelesUnited States
- Department of Chemistry and BiochemistryUniversity of California, Los AngelesLos AngelesUnited States
- California NanoSystems InstituteUniversity of California, Los AngelesLos AngelesUnited States
| | | | - Jaime de Anda
- Department of BioengineeringUniversity of California, Los AngelesLos AngelesUnited States
- Department of Chemistry and BiochemistryUniversity of California, Los AngelesLos AngelesUnited States
- California NanoSystems InstituteUniversity of California, Los AngelesLos AngelesUnited States
| | - Aiguo Xia
- Hefei National Laboratory for Physical Sciences at the MicroscaleUniversity of Science and Technology of ChinaHefeiChina
| | - Kun Zhao
- Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and TechnologyTianjin UniversityTianjinChina
- Collaborative Innovation Centre of Chemical Science and EngineeringTianjin UniversityTianjinChina
| | - Keiji Murakami
- Department of Oral Microbiology, Institute of Biomedical SciencesTokushima University Graduate SchoolTokushimaJapan
| | - Boo Shan Tseng
- School of Life SciencesUniversity of NevadaLas VegasUnited States
| | - Lucas R Hoffman
- Department of MicrobiologyUniversity of WashingtonSeattleUnited States
- Department of PediatricsUniversity of WashingtonSeattleUnited States
| | - Fan Jin
- Hefei National Laboratory for Physical Sciences at the MicroscaleUniversity of Science and Technology of ChinaHefeiChina
- Institute of Synthetic BiologyShenzhen Institutes of Advanced Technology, Chinese Academy of SciencesShenzhenChina
| | | | - Gerard CL Wong
- Department of BioengineeringUniversity of California, Los AngelesLos AngelesUnited States
- Department of Chemistry and BiochemistryUniversity of California, Los AngelesLos AngelesUnited States
- California NanoSystems InstituteUniversity of California, Los AngelesLos AngelesUnited States
| | - Matthew R Parsek
- Department of MicrobiologyUniversity of WashingtonSeattleUnited States
- Integrative Microbiology Research CentreSouth China Agricultural UniversityGuangzhouChina
| |
Collapse
|
109
|
Abstract
A number of microorganisms leave persistent trails while moving along surfaces. For single-cell organisms, the trail-mediated self-interaction will influence the dynamics. It has been discussed recently [Kranz et al., Phys. Rev. Lett. 117, 038101 (2016)] that the self-interaction may localize the organism above a critical coupling χc to the trail. Here, we will derive a generalized active particle model capturing the key features of the self-interaction and analyze its behavior for smaller couplings χ < χc. We find that fluctuations in propulsion speed shift the localization transition to stronger couplings.
Collapse
Affiliation(s)
- W Till Kranz
- Institute for Theoretical Physics, Universität zu Köln, Zülpicher Straße 77, 50937 Köln, Germany
| | - Ramin Golestanian
- Rudolf Peierls Centre for Theoretical Physics, University of Oxford, Oxford OX1 3NP, United Kingdom
| |
Collapse
|
110
|
Rossy T, Nadell CD, Persat A. Cellular advective-diffusion drives the emergence of bacterial surface colonization patterns and heterogeneity. Nat Commun 2019; 10:2471. [PMID: 31171786 PMCID: PMC6554397 DOI: 10.1038/s41467-019-10469-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 05/13/2019] [Indexed: 01/10/2023] Open
Abstract
Microorganisms navigate and divide on surfaces to form multicellular structures called biofilms, the most widespread survival strategy found in the bacterial world. One common assumption is that cellular components guide the spatial architecture and arrangement of multiple species in a biofilm. However, bacteria must contend with mechanical forces generated through contact with surfaces and under fluid flow, whose contributions to colonization patterns are poorly understood. Here, we show how the balance between motility and flow promotes the emergence of morphological patterns in Caulobacter crescentus biofilms. By modeling transport of single cells by flow and Brownian-like swimming, we show that the emergence of these patterns is guided by an effective Péclet number. By analogy with transport phenomena we show that, counter-intuitively, fluid flow represses mixing of distinct clonal lineages, thereby affecting the interaction landscapes between biofilm-dwelling bacteria. This demonstrates that hydrodynamics influence species interaction and evolution within surface-associated communities. In the wild, bacteria grow into structures called biofilms. Here the authors demonstrate that their spatial organization and heterogeneity depends on the interplay between fluid flow and single cell motility; this highlights the role of hydrodynamics in biofilm formation.
Collapse
Affiliation(s)
- Tamara Rossy
- Institute of Bioengineering and Global Health Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, 1015, Switzerland
| | - Carey D Nadell
- Department of Biological Sciences, Dartmouth, Hanover, NH, 03755, USA.
| | - Alexandre Persat
- Institute of Bioengineering and Global Health Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, 1015, Switzerland.
| |
Collapse
|
111
|
Treatment with the Pseudomonas aeruginosa Glycoside Hydrolase PslG Combats Wound Infection by Improving Antibiotic Efficacy and Host Innate Immune Activity. Antimicrob Agents Chemother 2019; 63:AAC.00234-19. [PMID: 30988141 DOI: 10.1128/aac.00234-19] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 04/04/2019] [Indexed: 12/25/2022] Open
Abstract
Pseudomonas aeruginosa is an opportunistic, nosocomial bacterial pathogen that forms persistent infections due to the formation of protective communities, known as biofilms. Once the biofilm is formed, the bacteria embedded within it are recalcitrant to antimicrobial treatment and host immune defenses. Moreover, the presence of biofilms in wounds is correlated with chronic infection and delayed healing. The current standard of care for chronic wound infections typically involves physical disruption of the biofilm via debridement and subsequent antimicrobial treatment. The glycoside hydrolases PelAh and PslGh have been demonstrated in vitro to disrupt biofilm integrity through degradation of the key biofilm matrix exopolysaccharides Pel and Psl, respectively. Herein, we demonstrate that PslGh hydrolase therapy is a promising strategy for controlling P. aeruginosa wound infections. Hydrolase treatment of P. aeruginosa biofilms resulted in increased antibiotic efficacy and penetration into the biofilm. PslGh treatment of P. aeruginosa biofilms also improved innate immune activity leading to greater complement deposition, neutrophil phagocytosis, and neutrophil reactive oxygen species production. Furthermore, when P. aeruginosa-infected wounds were treated with a combination of PslGh and tobramycin, we observed an additive effect leading to greater bacterial clearance than treatments of tobramycin or PslGh alone. This study demonstrates that PelAh and PslGh have promising therapeutic potential and that PslGh may aid in the treatment of P. aeruginosa wound infections.
Collapse
|
112
|
Høiby N, Henneberg KÅ, Wang H, Stavnsbjerg C, Bjarnsholt T, Ciofu O, Johansen UR, Sams T. Formation of Pseudomonas aeruginosa inhibition zone during tobramycin disk diffusion is due to transition from planktonic to biofilm mode of growth. Int J Antimicrob Agents 2019; 53:564-573. [DOI: 10.1016/j.ijantimicag.2018.12.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 12/17/2018] [Accepted: 12/23/2018] [Indexed: 12/21/2022]
|
113
|
Study on the Attachment of Escherichia coli to Sediment Particles at a Single-Cell Level: The Effect of Particle Size. WATER 2019. [DOI: 10.3390/w11040819] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The attachment of bacteria to sediment particles has a significant impact on the level of bacterial contamination in water. In this work, the attachment of Escherichia coli to particles was investigated with emphasis on the effect of particle size. To exclude the impact of other facts, e.g., the irregularity of particles, we used regular spherical glass particles in addition to natural sediment particles. Both types of particles are mainly composed of SiO2 and are similar in density. Through a bacterial tracking method together with microfluidic techniques, the attachment of single Escherichia coli cells on the particles was observed. The results showed that only a small portion of the cells that approach the particles remain attached and that the attachment probability per approach increases with surface area for both sediment and glass particles within the size range (8–62 μm) examined in this study. Therefore, finer sediments with more surface area have a higher E. coli attachment capacity. The attachment probability is higher on sediment particles than on glass microspheres of equivalent size, indicating preferential attachment of E. coli to sediment particles. The partition coefficient of the commonly used linear partition model was calculated based on microscopic measurements and the obtained relation of the partition coefficient with attachment probability and particle size was validated with data from the published literature.
Collapse
|
114
|
STUDY OF THE INFLUENCE OF SAVINASE®EVITY16L ENZYME ON BIOFILMS FORMATION OF STAPHYLOCOCCUS AUREUS ON STAINLESS STEEL WITH DIFFERENT ROUGHNESS. EUREKA: LIFE SCIENCES 2019. [DOI: 10.21303/2504-5695.2019.00858] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Microbial films formation on the dairy equipment creates a serious problem, because they are difficult to eliminate by washing and disinfecting means that results in contaminating dairy products by microorganisms. The aim of the work was to study the influence of Savinase®Evity 16L proteolytic enzyme on the process of destructing biofilms, formed by Staphylococcus aureus on stainless steel with different surface roughness.
It has been established, that surface roughness of stainless steel influences the process of Savinase®Evity 16L enzyme penetration in a hollow and prevents the destruction of the biofilm matrix, created by Staphylococcus aureus.
It has been revealed, that after the influence of a proteolytic enzyme on Staphylococcus aureus biofilms, created on steel with roughness 0,16±0,018 mcm, the density decreased in 4,0 times (р≤0,05), comparing with a condition before processing. At roughness 0,63±0,087 mcm the density of formed biofilms decreased at the effect of Savinase®Evity 16L in 3,3times (р≤0,05) and the biofilm was characterized as a weak one. At the same time at stainless steel surfaces with roughness 2,68–0,95mcm, the density of biofilms decreased in 2,3–2,1times (р≤0,05), comparing with a condition before processing, and they were characterized as ones of the middle density. It has been also revealed, that the degradation intensity of biofilms under the influence of Savinase®Evity 16L enzyme at roughness 2,68–0,95 mcm was 1,7–1,9 times (р≤0,05) lower than at the surface with roughness 0,16±0,018 mcm.
So, the revealed degradation features of a biofilm, created by Staphylococcus aureus at surfaces of stainless steel of different roughness at the influence of Savinase®Evity 16L proteolytic enzyme give a possibility to substantiate the addition of proteolytic enzymes to the composition of washing means for dairy production. It is also offered to process the surface to the roughness no more than 0,63 mcm for producing food steel for raising the effectiveness of biofilms destruction by enzymes and for the sanitary processing.
Collapse
|
115
|
Morgan SJ, Lippman SI, Bautista GE, Harrison JJ, Harding CL, Gallagher LA, Cheng AC, Siehnel R, Ravishankar S, Usui ML, Olerud JE, Fleckman P, Wolcott RD, Manoil C, Singh PK. Bacterial fitness in chronic wounds appears to be mediated by the capacity for high-density growth, not virulence or biofilm functions. PLoS Pathog 2019; 15:e1007511. [PMID: 30893371 PMCID: PMC6448920 DOI: 10.1371/journal.ppat.1007511] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 04/04/2019] [Accepted: 12/07/2018] [Indexed: 12/19/2022] Open
Abstract
While much is known about acute infection pathogenesis, the understanding of chronic infections has lagged. Here we sought to identify the genes and functions that mediate fitness of the pathogen Pseudomonas aeruginosa in chronic wound infections, and to better understand the selective environment in wounds. We found that clinical isolates from chronic human wounds were frequently defective in virulence functions and biofilm formation, and that many virulence and biofilm formation genes were not required for bacterial fitness in experimental mouse wounds. In contrast, genes involved in anaerobic growth, some metabolic and energy pathways, and membrane integrity were critical. Consistent with these findings, the fitness characteristics of some wound impaired-mutants could be represented by anaerobic, oxidative, and membrane-stress conditions ex vivo, and more comprehensively by high-density bacterial growth conditions, in the absence of a host. These data shed light on the bacterial functions needed in chronic wound infections, the nature of stresses applied to bacteria at chronic infection sites, and suggest therapeutic targets that might compromise wound infection pathogenesis. Chronic infections are poorly understood, hard to model, and treatment resistant. Future progress depends upon understanding infection pathogenesis. Our study suggests that many bacterial virulence and biofilm formation functions are not required for fitness of infecting bacteria in chronic wounds. Instead, we found that functions that mitigate stresses associated with high-density bacterial growth are critical for infection. These findings suggest new approaches to model and target chronic bacterial infections.
Collapse
Affiliation(s)
- Sarah J. Morgan
- Department of Microbiology, University of Washington, Seattle, WA, United States of America
| | - Soyeon I. Lippman
- Department of Genome Sciences, University of Washington, Seattle, WA, United States of America
| | - Gilbert E. Bautista
- Department of Microbiology, University of Washington, Seattle, WA, United States of America
| | - Joe J. Harrison
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Christopher L. Harding
- Department of Microbiology, University of Washington, Seattle, WA, United States of America
| | - Larry A. Gallagher
- Department of Genome Sciences, University of Washington, Seattle, WA, United States of America
| | - Ann-Chee Cheng
- Department of Microbiology, University of Washington, Seattle, WA, United States of America
| | - Richard Siehnel
- Department of Microbiology, University of Washington, Seattle, WA, United States of America
| | - Sumedha Ravishankar
- Department of Microbiology, University of Washington, Seattle, WA, United States of America
| | - Marcia L. Usui
- Department of Medicine, University of Washington, Seattle WA, United States of America
| | - John E. Olerud
- Department of Medicine, University of Washington, Seattle WA, United States of America
| | - Philip Fleckman
- Department of Medicine, University of Washington, Seattle WA, United States of America
| | - Randall D. Wolcott
- Southwest Regional Wound Care Center, Lubbock, TX, United States of America
| | - Colin Manoil
- Department of Genome Sciences, University of Washington, Seattle, WA, United States of America
- * E-mail: (CM); (PKS)
| | - Pradeep K. Singh
- Department of Microbiology, University of Washington, Seattle, WA, United States of America
- * E-mail: (CM); (PKS)
| |
Collapse
|
116
|
Grinberg M, Orevi T, Kashtan N. Bacterial surface colonization, preferential attachment and fitness under periodic stress. PLoS Comput Biol 2019; 15:e1006815. [PMID: 30835727 PMCID: PMC6420035 DOI: 10.1371/journal.pcbi.1006815] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 03/15/2019] [Accepted: 01/23/2019] [Indexed: 12/31/2022] Open
Abstract
Early bacterial surface colonization is not a random process wherein cells arbitrarily attach to surfaces and grow; but rather, attachment events, movement and cellular interactions induce non-random spatial organization. We have only begun to understand how the apparent self-organization affects the fitness of the population. A key factor contributing to fitness is the tradeoff between solitary-planktonic and aggregated surface-attached biofilm lifestyles. Though planktonic cells typically grow faster, bacteria in aggregates are more resistant to stress such as desiccation, antibiotics and predation. Here we ask if and to what extent informed surface-attachments improve fitness during early surface colonization under periodic stress conditions. We use an individual-based modeling approach to simulate foraging planktonic cells colonizing a surface under alternating wet-dry cycles. Such cycles are common in the largest terrestrial microbial habitats–soil, roots, and leaf surfaces–that are not constantly saturated with water and experience daily periods of desiccation stress. We compared different surface-attachment strategies, and analyzed the emerging spatio-temporal dynamics of surface colonization and population yield as a measure of fitness. We demonstrate that a simple strategy of preferential attachment (PA), biased to dense sites, carries a large fitness advantage over any random attachment across a broad range of environmental conditions–particularly under periodic stress. A vast portion of bacterial life on Earth takes place on surfaces. In many of these surfaces cells collectively organize into biofilms that are known to provide them protection from various environmental stresses. Early bacterial colonization of surfaces, prior to the development of mature biofilm, is a critical stage during which cells attempt to establish a sustainable population. It is not a random process wherein cells arbitrarily attach to surfaces and grow to form micro-colonies. Rather, surface-attachments, movement and cellular interactions take place to yield non-random organization. Using computer simulations, based on individual-based modeling, we demonstrate that simple attachment strategies, where planktonic cells preferentially attach to existing surface-attached aggregates, may confer fitness advantage over random attachment. The advantage of preferential attachment is particularly substantial under periodic stress–a common characteristic of many natural microbial habitats. This is due to a more efficient recruitment of planktonic cells that accelerates the formation of stress-protected aggregates.
Collapse
Affiliation(s)
- Maor Grinberg
- The department of Plant Pathology and Microbiology, The Robert H Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Tomer Orevi
- The department of Plant Pathology and Microbiology, The Robert H Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Nadav Kashtan
- The department of Plant Pathology and Microbiology, The Robert H Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
- * E-mail:
| |
Collapse
|
117
|
Sugi T, Ito H, Nishimura M, Nagai KH. C. elegans collectively forms dynamical networks. Nat Commun 2019; 10:683. [PMID: 30778072 PMCID: PMC6379388 DOI: 10.1038/s41467-019-08537-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 01/16/2019] [Indexed: 11/16/2022] Open
Abstract
Understanding physical rules underlying collective motions requires perturbation of controllable parameters in self-propelled particles. However, controlling parameters in animals is generally not easy, which makes collective behaviours of animals elusive. Here, we report an experimental system in which a conventional model animal, Caenorhabditis elegans, collectively forms dynamical networks of bundle-shaped aggregates. We investigate the dependence of our experimental system on various extrinsic parameters (material of substrate, ambient humidity and density of worms). Taking advantage of well-established C. elegans genetics, we also control intrinsic parameters (genetically determined motility) by mutations and by forced neural activation via optogenetics. Furthermore, we develop a minimal agent-based model that reproduces the dynamical network formation and its dependence on the parameters, suggesting that the key factors are alignment of worms after collision and smooth turning. Our findings imply that the concepts of active matter physics may help us to understand biological functions of animal groups. Understanding collective motions in a group of interacting animal is a challenge owing to the lack of control over, for example, real fish schools. Here, the authors study the aggregation of C. elegans at controllable conditions and reproduce the experimental observations using a minimal model.
Collapse
Affiliation(s)
- Takuma Sugi
- Molecular Neuroscience Research Center, Shiga University of Medical Science, Otsu, Shiga, 520-2192, Japan.
| | - Hiroshi Ito
- Faculty of Design, Kyushu University, Fukuoka, 815-8540, Japan.
| | - Masaki Nishimura
- Molecular Neuroscience Research Center, Shiga University of Medical Science, Otsu, Shiga, 520-2192, Japan
| | - Ken H Nagai
- School of Materials Science, Japan Advanced Institute of Science and Technology, Nomi, Ishikawa, 923-1292, Japan.
| |
Collapse
|
118
|
Kugadas A, Geddes-McAlister J, Guy E, DiGiandomenico A, Sykes DB, Mansour MK, Mirchev R, Gadjeva M. Frontline Science: Employing enzymatic treatment options for management of ocular biofilm-based infections. J Leukoc Biol 2019; 105:1099-1110. [PMID: 30690787 PMCID: PMC6618031 DOI: 10.1002/jlb.4hi0918-364rr] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 01/15/2019] [Accepted: 01/16/2019] [Indexed: 12/22/2022] Open
Abstract
Pseudomonas aeruginosa-induced corneal keratitis is a sight-threatening disease. The rise of antibiotic resistance among P. aeruginosa keratitis isolates makes treatment of this disease challenging, emphasizing the need for alternative therapeutic modalities. By comparing the responses to P. aeruginosa infection between an outbred mouse strain (Swiss Webster, SW) and a susceptible mouse strain (C57BL6/N), we found that the inherent neutrophil-killing abilities of these strains correlated with their susceptibility to infection. Namely, SW-derived neutrophils were significantly more efficient at killing P. aeruginosa in vitro than C57BL6/N-derived neutrophils. To interrogate whether the distinct neutrophil killing capacities were dependent on endogenous or exogenous factors, neutrophil progenitor cell lines were generated. The in vitro differentiated neutrophils from either SW or C57BL6/N progenitors retained the differential killing abilities, illustrating that endogenous factors conferred resistance. Consistently, quantitative LC-MS/MS analysis revealed strain-specific and infection-induced alterations of neutrophil proteomes. Among the distinctly elevated proteins in the SW-derived proteomes were α-mannosidases, potentially associated with protection. Inhibition of α-mannosidases reduced neutrophil bactericidal functions in vitro. Conversely, topical application of α-mannosidases reduced bacterial biofilms and burden of infected corneas. Cumulatively, these data suggest novel therapeutic approaches to control bacterial biofilm assembly and improve bacterial clearance via enzymatic treatments.
Collapse
Affiliation(s)
- Abirami Kugadas
- Department of Medicine, Division of Infectious Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Jennifer Geddes-McAlister
- Proteomics and Signal Transduction Department, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Emilia Guy
- Department of Medicine, Division of Infectious Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | | | - David B Sykes
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Michael K Mansour
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Rossen Mirchev
- Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, USA
| | - Mihaela Gadjeva
- Department of Medicine, Division of Infectious Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| |
Collapse
|
119
|
Abstract
Most living systems, from individual cells to tissues and swarms, display collective self-organization on length scales that are much larger than those of the individual units that drive this organization. A fundamental challenge is to understand how properties of microscopic components determine macroscopic, multicellular biological function. Our study connects intracellular physiology to macroscale collective behaviors during multicellular development, spanning five orders of magnitude in length and six orders of magnitude in time, using bacterial swarming as a model system. This work is enabled by a high-throughput adaptive microscopy technique, which we combined with genetics, machine learning, and mathematical modeling to reveal the phase diagram of bacterial swarming and that cell–cell interactions within each swarming phase are dominated by mechanical interactions. Coordinated dynamics of individual components in active matter are an essential aspect of life on all scales. Establishing a comprehensive, causal connection between intracellular, intercellular, and macroscopic behaviors has remained a major challenge due to limitations in data acquisition and analysis techniques suitable for multiscale dynamics. Here, we combine a high-throughput adaptive microscopy approach with machine learning, to identify key biological and physical mechanisms that determine distinct microscopic and macroscopic collective behavior phases which develop as Bacillus subtilis swarms expand over five orders of magnitude in space. Our experiments, continuum modeling, and particle-based simulations reveal that macroscopic swarm expansion is primarily driven by cellular growth kinetics, whereas the microscopic swarming motility phases are dominated by physical cell–cell interactions. These results provide a unified understanding of bacterial multiscale behavioral complexity in swarms.
Collapse
|
120
|
Tovi N, Frenk S, Hadar Y, Minz D. Host Specificity and Spatial Distribution Preference of Three Pseudomonas Isolates. Front Microbiol 2019; 9:3263. [PMID: 30687261 PMCID: PMC6335278 DOI: 10.3389/fmicb.2018.03263] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 12/14/2018] [Indexed: 12/17/2022] Open
Abstract
Plant hosts recruit and maintain a distinct root-associated microbiota based on host and bacterium traits. However, past studies disregarded microbial strain-host specificity and spatial micro-heterogeneity of the root compartment. Using genetic manipulation, confocal laser scanning microscopy, real-time quantitative PCR, and genome sequencing we characterized the colonization patterns of three Pseudomonas spp. isolates native to wheat roots, on the micro-scale. Namely, isolates P. fluorescens NT0133, P. stutzeri NT124, and P. stutzeri NT128. All three isolates preferentially colonized wheat over cucumber roots that served as control for host specificity. Furthermore, not only had the isolates strong host specificity but each isolate had a distinct spatial distribution on the root, all within a few millimeters. Isolate P. stutzeri-NT0124 preferentially colonized root tips, whereas P. fluorescens-NT0133 showed a preference for zones distant from the tip. In contrast, isolate P. stutzeri-NT0128 had no preference for a specific niche on the root. While all isolates maintained genetic potential for motility and biofilm formation their phenotype varied significantly and corresponded to their niche preference. These results demonstrate the importance of spatial colonization patterns, governed by both niche and bacterial characteristics which will have great importance in future attempts to manipulate the plant microbiome by constructing synthetic microbial consortia.
Collapse
Affiliation(s)
- Nesli Tovi
- Department of Soil, Water, and Environmental Sciences, Agricultural Research Organization–Volcani Center, Rishon LeZion, Israel
- Department of Plant Pathology and Microbiology, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Sammy Frenk
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, Australia
| | - Yitzhak Hadar
- Department of Plant Pathology and Microbiology, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Dror Minz
- Department of Soil, Water, and Environmental Sciences, Agricultural Research Organization–Volcani Center, Rishon LeZion, Israel
| |
Collapse
|
121
|
Biological synthesis of high-conductive pili in aerobic bacterium Pseudomonas aeruginosa. Appl Microbiol Biotechnol 2018; 103:1535-1544. [PMID: 30523372 DOI: 10.1007/s00253-018-9484-5] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 10/22/2018] [Indexed: 10/27/2022]
Abstract
Bioelectrical nanowires as ecomaterials have great potential on environmental applications. A wide range of bacteria can express type IV pili (T4P), which are long protein fibers assembled from PilA. The T4P of Geobacter sulfurreducens are well known as "microbial nanowires," yet T4P of Pseudomonas aeruginosa (PaT4P) was believed to be poorly conductive. P. aeruginosa is an aerobic and electrochemically active bacterium. Its T4P have been known to be responsible for surface attachment, twitching motility and biofilm formation. Here, we show that PaT4P can be highly conductive while assembled by a truncated P. aeruginosa PilA (PaPilA) containing only N-terminus 61 amino acids. Furthermore, increasing the number of aromatic amino acids in the PaPilA1-61 significantly enhances the conductivity of pili and the bioelectricity output of P. aeruginosa in microbial fuel cell system, suggesting a potential application of PaT4P as a conductive nanomaterial. The N-terminal region of PilA from diverse eubacteria is highly conserved, implying a general way to synthesize highly conductive microbial nanowires and to increase the bioelectricity output of microbial fuel cell.
Collapse
|
122
|
Pönisch W, Eckenrode KB, Alzurqa K, Nasrollahi H, Weber C, Zaburdaev V, Biais N. Pili mediated intercellular forces shape heterogeneous bacterial microcolonies prior to multicellular differentiation. Sci Rep 2018; 8:16567. [PMID: 30410109 PMCID: PMC6224386 DOI: 10.1038/s41598-018-34754-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 10/24/2018] [Indexed: 11/18/2022] Open
Abstract
Microcolonies are aggregates of a few dozen to a few thousand cells exhibited by many bacteria. The formation of microcolonies is a crucial step towards the formation of more mature bacterial communities known as biofilms, but also marks a significant change in bacterial physiology. Within a microcolony, bacteria forgo a single cell lifestyle for a communal lifestyle hallmarked by high cell density and physical interactions between cells potentially altering their behaviour. It is thus crucial to understand how initially identical single cells start to behave differently while assembling in these tight communities. Here we show that cells in the microcolonies formed by the human pathogen Neisseria gonorrhoeae (Ng) present differential motility behaviors within an hour upon colony formation. Observation of merging microcolonies and tracking of single cells within microcolonies reveal a heterogeneous motility behavior: cells close to the surface of the microcolony exhibit a much higher motility compared to cells towards the center. Numerical simulations of a biophysical model for the microcolonies at the single cell level suggest that the emergence of differential behavior within a multicellular microcolony of otherwise identical cells is of mechanical origin. It could suggest a route toward further bacterial differentiation and ultimately mature biofilms.
Collapse
Affiliation(s)
- Wolfram Pönisch
- Max-Planck-Institute for the Physics of Complex Systems, Dresden, Germany
- MRC Laboratory for Molecular Cell Biology, University City London, London, UK
| | - Kelly B Eckenrode
- Brooklyn College of CUNY, Department of Biology, Brooklyn, USA
- Graduate Center of CUNY, New York, USA
| | - Khaled Alzurqa
- Brooklyn College of CUNY, Department of Biology, Brooklyn, USA
| | - Hadi Nasrollahi
- Brooklyn College of CUNY, Department of Biology, Brooklyn, USA
| | - Christoph Weber
- Max-Planck-Institute for the Physics of Complex Systems, Dresden, Germany
| | - Vasily Zaburdaev
- Max-Planck-Institute for the Physics of Complex Systems, Dresden, Germany.
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany.
| | - Nicolas Biais
- Brooklyn College of CUNY, Department of Biology, Brooklyn, USA.
- Graduate Center of CUNY, New York, USA.
| |
Collapse
|
123
|
Zhai C, Zhang W, Zhang J, Ma LZ, Zhao K. Overshadow Effect of Psl on Bacterial Response to Physiochemically Distinct Surfaces Through Motility-Based Characterization. Front Cell Infect Microbiol 2018; 8:383. [PMID: 30420944 PMCID: PMC6215810 DOI: 10.3389/fcimb.2018.00383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 10/10/2018] [Indexed: 11/24/2022] Open
Abstract
Biofilms of Pseudomonas aeruginosa are ubiquitously found on surfaces of many medical devices, which are the major cause of hospital-acquired infections. A large amount of work has been focused on bacterial attachment on surfaces. However, how bacterial cells evolve on surfaces after their attachment is the key to get better understanding and further control of biofilm formation. In this work, by employing both single-cell- and collective-motility of cells, we characterized the bacterial surface movement on physiochemically distinct surfaces. The measurement of cell surface motility showed consistent results that gold and especially platinum surfaces displayed a stronger capability in microcolony formation than polyvinyl chloride and polycarbonate surfaces. More interestingly, we found that overproduction of Psl led to a narrower variance in cell surface motility among tested surfaces, indicating an overshadow effect of Psl for bacteria by screening the influence of physicochemical properties of solid surfaces. Our results provide insights into how Pseudomonas aeruginosa cells adapt their motion to physiochemically distinct surfaces, and thus would be beneficial for developing new anti-biofouling techniques in biomedical engineering.
Collapse
Affiliation(s)
- Chunhui Zhai
- Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
| | - Wenchao Zhang
- Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
| | - Jingchao Zhang
- Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
| | - Luyan Z. Ma
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Kun Zhao
- Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
| |
Collapse
|
124
|
Zhao T, Zhang Y, Wu H, Wang D, Chen Y, Zhu MJ, Ma LZ. Extracellular aminopeptidase modulates biofilm development of Pseudomonas aeruginosa by affecting matrix exopolysaccharide and bacterial cell death. ENVIRONMENTAL MICROBIOLOGY REPORTS 2018; 10:583-593. [PMID: 30047246 DOI: 10.1111/1758-2229.12682] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 07/19/2018] [Indexed: 06/08/2023]
Abstract
Biofilm bacteria are embedded within a self-secreted extracellular matrix that contains a considerable amount of proteins including many extracellular enzymes. However, little is known about the roles of such enzymes in biofilm development. Here, we studied Pseudomonas aeruginosa aminopeptidase (PaAP, encoded by PA2939 that we named the gene as paaP in this study), a quorum-sensing-regulated enzyme and one of the most abundant extracellular proteins in the biofilm matrix of this opportunistic pathogen and environmental bacterium. We found that deletion of paaP in P. aeruginosa increased initial attachment and biofilm formation at early stages of biofilm development. After 24 h growth, loss of PaAP resulted in substantial cell death and biofilm disruption. Bacterial cell death was independent of biofilm matrix polysaccharide Psl, while biofilm disruption was due to the degradation of Psl matrix by dead-bacteria-released glycosyl hydrolase PslG, thereby leading to biofilm dispersion. PaAP functioned extracellularly and aminopeptidase catalytic activity was essential for its effect on biofilm development. Our data reveal an important role of extracellular aminopeptidase in biofilm development, suggesting PaAP as a therapeutic target for preventing P. aeruginosa infection and combating biofilm-related complications.
Collapse
Affiliation(s)
- Tianhu Zhao
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- School of Biological Science, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yuhuan Zhang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- School of Biological Science, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Huijun Wu
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- School of Biological Science, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Di Wang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yihua Chen
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- School of Biological Science, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Mei-Jun Zhu
- School of Food Science, Washington State University, Pullman, Washington 99164, USA
| | - Luyan Z Ma
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- School of Biological Science, University of Chinese Academy of Sciences, Beijing 100049, China
| |
Collapse
|
125
|
Zhang W, Ju Y, Zong Y, Qi H, Zhao K. In Situ Real-Time Study on Dynamics of Microbially Induced Calcium Carbonate Precipitation at a Single-Cell Level. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:9266-9276. [PMID: 30036465 DOI: 10.1021/acs.est.8b02660] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Ureolytic microbially induced calcium carbonate precipitation (MICP) is a promising green technique for addressing a variety of environmental and architectural concerns. However, the dynamics of MICP especially at the microscopic level remains relatively unexplored. In this work, by applying a bacterial tracking technique, the growth dynamics of micrometer-sized calcium carbonate precipitates induced by Sporosarcina pasteurii were studied at a single-cell resolution. The growth of micrometer-scale precipitates and the occurrence and dissolution of many unstable submicrometer calcium carbonate particles were observed in the precipitation process. More interestingly, we observed that micrometer-sized precipitated crystals did not grow on negatively charged cell surfaces nor on other tested polystyrene microspheres with different negatively charged surface modifications, indicating that a negatively charged surface was not a sufficient property for nucleating the growth of precipitates in the MICP process under the conditions used in this study. Our observations imply that the frequently cited model of bacterial cell surfaces as nucleation sites for precipitates during MICP is oversimplified. In addition, additional growth of calcium carbonates was observed on old precipitates collected from previous runs. The presence of bacterial cells was also shown to affect both morphologies and crystalline structures of precipitates, and both calcite and vaterite precipitates were found when cells physically coexisted with precipitates. This study provides new insights into the regulation of MICP through dynamic control of precipitation.
Collapse
Affiliation(s)
- Wenchao Zhang
- Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology , Tianjin University , Tianjin 300072 , China
| | - Ying Ju
- Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology , Tianjin University , Tianjin 300072 , China
| | - Yiwu Zong
- Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology , Tianjin University , Tianjin 300072 , China
| | - Hao Qi
- Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology , Tianjin University , Tianjin 300072 , China
| | - Kun Zhao
- Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology , Tianjin University , Tianjin 300072 , China
- Collaborative Innovation Centre of Chemical Science and Engineering , Tianjin University , Tianjin 300072 , China
| |
Collapse
|
126
|
Berne C, Ellison CK, Ducret A, Brun YV. Bacterial adhesion at the single-cell level. Nat Rev Microbiol 2018; 16:616-627. [DOI: 10.1038/s41579-018-0057-5] [Citation(s) in RCA: 266] [Impact Index Per Article: 44.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
127
|
Differential Production of Psl in Planktonic Cells Leads to Two Distinctive Attachment Phenotypes in Pseudomonas aeruginosa. Appl Environ Microbiol 2018; 84:AEM.00700-18. [PMID: 29752273 PMCID: PMC6029103 DOI: 10.1128/aem.00700-18] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 05/05/2018] [Indexed: 01/21/2023] Open
Abstract
The attachment of planktonic cells to surfaces is the first and most crucial step in biofilm formation. In this paper, we show that planktonic cells of Pseudomonas aeruginosa differently attach to surfaces. Typically, in the later exponential phase, approximately 80% of the cells can quickly attach to surfaces within 15 min, whereas approximately 20% of the cells slowly attach to surfaces, which greatly affects the initial stage of biofilm formation in the presence of flows. This is because fast-attaching cells are more likely to attach on surfaces to form microcolonies, whereas slow-attaching cells are more likely to remain in the mobile phase. This scenario is different from the previous understanding of biofilm formation in the initial stage, in which planktonic cells were thought to uniformly attach to surfaces. Most notably, the results of this study show that the different attachment manner of planktonic cells to surfaces affects the subsequent stages of biofilm formation. This research highlights that the phenotypic variations in planktonic cells plays significant roles in various stages of biofilm formation. Exponentially growing bacteria in a well-mixed planktonic culture are generally assumed to be physiologically and phenotypically uniform and distinct from their genetically identical counterparts living in biofilms. Using a combination of high spatiotemporal microscopy and a bacterial tracking algorithm, in this study, we showed that planktonic cells of Pseudomonas aeruginosa differently attached to surfaces even when they remained in the exponential phase. We consistently observed that fast- and slow-attaching phenotypes coexist in planktonic cells, regardless of their growth phase. Furthermore, we found that (i) the distinct attaching phenotypes of planktonic cells resulted from the differential production of Psl and (ii) the RsmYZ/RsmA signaling pathway mainly regulated the differential production of Psl. Our results indicate that the differential production of Psl in P. aeruginosa plays a significant role in biofilm development and formation. IMPORTANCE The attachment of planktonic cells to surfaces is the first and most crucial step in biofilm formation. In this paper, we show that planktonic cells of Pseudomonas aeruginosa differently attach to surfaces. Typically, in the later exponential phase, approximately 80% of the cells can quickly attach to surfaces within 15 min, whereas approximately 20% of the cells slowly attach to surfaces, which greatly affects the initial stage of biofilm formation in the presence of flows. This is because fast-attaching cells are more likely to attach on surfaces to form microcolonies, whereas slow-attaching cells are more likely to remain in the mobile phase. This scenario is different from the previous understanding of biofilm formation in the initial stage, in which planktonic cells were thought to uniformly attach to surfaces. Most notably, the results of this study show that the different attachment manner of planktonic cells to surfaces affects the subsequent stages of biofilm formation. This research highlights that the phenotypic variations in planktonic cells plays significant roles in various stages of biofilm formation.
Collapse
|
128
|
Effects of PslG on the Surface Movement of Pseudomonas aeruginosa. Appl Environ Microbiol 2018; 84:AEM.00219-18. [PMID: 29728385 DOI: 10.1128/aem.00219-18] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 04/25/2018] [Indexed: 01/09/2023] Open
Abstract
PslG attracted a lot of attention recently due to its great potential abilities in inhibiting biofilms of Pseudomonas aeruginosa However, how PslG affects biofilm development still remains largely unexplored. Here, we focused on the surface motility of bacterial cells, which is critical for biofilm development. We studied the effects of PslG on bacterial surface movement in early biofilm development at a single-cell resolution by using a high-throughput bacterial tracking technique. The results showed that compared with no exogenous PslG addition, when PslG was added to the medium, bacterial surface movement was significantly (4 to 5 times) faster and proceeded in a more random way with no clear preferred direction. A further study revealed that the fraction of walking mode increased when PslG was added, which then resulted in an elevated average speed. The differences of motility due to PslG addition led to a clear distinction in patterns of bacterial surface movement and retarded microcolony formation greatly. Our results provide insight into developing new PslG-based biofilm control techniques.IMPORTANCE Biofilms of Pseudomonas aeruginosa are a major cause for hospital-acquired infections. They are notoriously difficult to eradicate and pose serious health hazards to human society. So, finding new ways to control biofilms is urgently needed. Recent work on PslG showed that PslG might be a good candidate for inhibiting/disassembling biofilms of Pseudomonas aeruginosa through Psl-based regulation. However, to fully explore PslG functions in biofilm control, a better understanding of PslG-Psl interactions is needed. Toward this end, we examined the effects of PslG on the surface movement of Pseudomonas aeruginosa in this work. The significance of our work is in greatly enhancing our understanding of the inhibiting mechanism of PslG on biofilms by providing a detailed picture of bacterial surface movement at a single-cell level, which will allow a full understanding of PslG abilities in biofilm control and thus present potential applications in biomedical fields.
Collapse
|
129
|
Conrad JC, Poling-Skutvik R. Confined Flow: Consequences and Implications for Bacteria and Biofilms. Annu Rev Chem Biomol Eng 2018; 9:175-200. [DOI: 10.1146/annurev-chembioeng-060817-084006] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Bacteria overwhelmingly live in geometrically confined habitats that feature small pores or cavities, narrow channels, or nearby interfaces. Fluid flows through these confined habitats are ubiquitous in both natural and artificial environments colonized by bacteria. Moreover, these flows occur on time and length scales comparable to those associated with motility of bacteria and with the formation and growth of biofilms, which are surface-associated communities that house the vast majority of bacteria to protect them from host and environmental stresses. This review describes the emerging understanding of how flow near surfaces and within channels and pores alters physical processes that control how bacteria disperse, attach to surfaces, and form biofilms. This understanding will inform the development and deployment of technologies for drug delivery, water treatment, and antifouling coatings and guide the structuring of bacterial consortia for production of chemicals and pharmaceuticals.
Collapse
Affiliation(s)
- Jacinta C. Conrad
- Department of Chemical and Biomolecular Engineering, University of Houston, Houston, Texas 77204, USA
| | - Ryan Poling-Skutvik
- Department of Chemical and Biomolecular Engineering, University of Houston, Houston, Texas 77204, USA
| |
Collapse
|
130
|
Non-eluting, surface-bound enzymes disrupt surface attachment of bacteria by continuous biofilm polysaccharide degradation. Biomaterials 2018; 167:168-176. [DOI: 10.1016/j.biomaterials.2018.03.016] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 02/28/2018] [Accepted: 03/12/2018] [Indexed: 11/19/2022]
|
131
|
Vourc'h T, Peerhossaini H, Léopoldès J, Méjean A, Chauvat F, Cassier-Chauvat C. Slowdown of surface diffusion during early stages of bacterial colonization. Phys Rev E 2018; 97:032407. [PMID: 29776183 DOI: 10.1103/physreve.97.032407] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Indexed: 12/17/2022]
Abstract
We study the surface diffusion of the model cyanobacterium Synechocystis sp. PCC6803 during the incipient stages of cell contact with a glass surface in the dilute regime. We observe a twitching motility with alternating immobile tumble and mobile run periods, resulting in a normal diffusion described by a continuous-time random walk with a coefficient of diffusion D. Surprisingly, D is found to decrease with time down to a plateau. This is observed only when the cyanobacterial cells are able to produce released extracellular polysaccharides, as shown by a comparative study between the wild-type strain and various polysaccharides-depleted mutants. The analysis of the trajectories taken by the bacterial cells shows that the temporal characteristics of their intermittent motion depend on the instantaneous fraction of visited sites during diffusion. This describes quantitatively the time dependence of D, related to the progressive surface coverage by the polysaccharides. The observed slowdown of the surface diffusion may constitute a basic precursor mechanism for microcolony formation and provides clues for controlling biofilm formation.
Collapse
Affiliation(s)
- T Vourc'h
- Laboratoire AstroParticules et Cosmologie, CNRS, Université Paris-Diderot, Université Sorbonne Paris Cité, 5 Rue Thomas Mann, 75013 Paris, France
| | - H Peerhossaini
- Laboratoire AstroParticules et Cosmologie, CNRS, Université Paris-Diderot, Université Sorbonne Paris Cité, 5 Rue Thomas Mann, 75013 Paris, France
| | - J Léopoldès
- ESPCI Paris, PSL Research University, CNRS, Institut Langevin, 1 Rue Jussieu, 75005 Paris, France and Université Paris-Est Marne-la-Vallée, 5 Boulevard Descartes, Champs sur Marne, Marne-la-Vallée Cedex 2, France
| | - A Méjean
- Laboratoire Interdisciplinaire des Énergies de Demain, CNRS, Université Paris-Diderot, Université Sorbonne Paris Cité, 5 Rue Thomas Mann, 75013 Paris, France
| | - F Chauvat
- Laboratory of Biology and Biotechnology of Cyanobacteria. Institute for Integrative Biology of the Cell, CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette Cedex, France
| | - C Cassier-Chauvat
- Laboratory of Biology and Biotechnology of Cyanobacteria. Institute for Integrative Biology of the Cell, CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette Cedex, France
| |
Collapse
|
132
|
Lee CK, de Anda J, Baker AE, Bennett RR, Luo Y, Lee EY, Keefe JA, Helali JS, Ma J, Zhao K, Golestanian R, O'Toole GA, Wong GCL. Multigenerational memory and adaptive adhesion in early bacterial biofilm communities. Proc Natl Acad Sci U S A 2018; 115:4471-4476. [PMID: 29559526 PMCID: PMC5924909 DOI: 10.1073/pnas.1720071115] [Citation(s) in RCA: 106] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Using multigenerational, single-cell tracking we explore the earliest events of biofilm formation by Pseudomonas aeruginosa During initial stages of surface engagement (≤20 h), the surface cell population of this microbe comprises overwhelmingly cells that attach poorly (∼95% stay <30 s, well below the ∼1-h division time) with little increase in surface population. If we harvest cells previously exposed to a surface and direct them to a virgin surface, we find that these surface-exposed cells and their descendants attach strongly and then rapidly increase the surface cell population. This "adaptive," time-delayed adhesion requires determinants we showed previously are critical for surface sensing: type IV pili (TFP) and cAMP signaling via the Pil-Chp-TFP system. We show that these surface-adapted cells exhibit damped, coupled out-of-phase oscillations of intracellular cAMP levels and associated TFP activity that persist for multiple generations, whereas surface-naïve cells show uncorrelated cAMP and TFP activity. These correlated cAMP-TFP oscillations, which effectively impart intergenerational memory to cells in a lineage, can be understood in terms of a Turing stochastic model based on the Pil-Chp-TFP framework. Importantly, these cAMP-TFP oscillations create a state characterized by a suppression of TFP motility coordinated across entire lineages and lead to a drastic increase in the number of surface-associated cells with near-zero translational motion. The appearance of this surface-adapted state, which can serve to define the historical classification of "irreversibly attached" cells, correlates with family tree architectures that facilitate exponential increases in surface cell populations necessary for biofilm formation.
Collapse
Affiliation(s)
- Calvin K Lee
- Department of Bioengineering, University of California Los Angeles, CA 90095
- Department of Chemistry and Biochemistry, University of California Los Angeles, CA 90095
- California NanoSystems Institute, University of California Los Angeles, CA 90095
| | - Jaime de Anda
- Department of Bioengineering, University of California Los Angeles, CA 90095
- Department of Chemistry and Biochemistry, University of California Los Angeles, CA 90095
- California NanoSystems Institute, University of California Los Angeles, CA 90095
| | - Amy E Baker
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755
| | - Rachel R Bennett
- Rudolf Peierls Centre for Theoretical Physics, University of Oxford, OX1 3NP Oxford, United Kingdom
- Department of Physics, University of Pennsylvania, Philadelphia, PA 19104
| | - Yun Luo
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755
- DuPont Industrial Bioscience, Palo Alto, CA 94304
| | - Ernest Y Lee
- Department of Bioengineering, University of California Los Angeles, CA 90095
- Department of Chemistry and Biochemistry, University of California Los Angeles, CA 90095
- California NanoSystems Institute, University of California Los Angeles, CA 90095
| | - Joshua A Keefe
- Department of Bioengineering, University of California Los Angeles, CA 90095
- Department of Chemistry and Biochemistry, University of California Los Angeles, CA 90095
- California NanoSystems Institute, University of California Los Angeles, CA 90095
| | - Joshua S Helali
- Department of Bioengineering, University of California Los Angeles, CA 90095
- Department of Chemistry and Biochemistry, University of California Los Angeles, CA 90095
- California NanoSystems Institute, University of California Los Angeles, CA 90095
| | - Jie Ma
- Department of Bioengineering, University of California Los Angeles, CA 90095
- Department of Chemistry and Biochemistry, University of California Los Angeles, CA 90095
- California NanoSystems Institute, University of California Los Angeles, CA 90095
| | - Kun Zhao
- Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, People's Republic of China;
- SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin 300072, People's Republic of China
| | - Ramin Golestanian
- Rudolf Peierls Centre for Theoretical Physics, University of Oxford, OX1 3NP Oxford, United Kingdom;
| | - George A O'Toole
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755;
| | - Gerard C L Wong
- Department of Bioengineering, University of California Los Angeles, CA 90095;
- Department of Chemistry and Biochemistry, University of California Los Angeles, CA 90095
- California NanoSystems Institute, University of California Los Angeles, CA 90095
| |
Collapse
|
133
|
Lai CQ. Bacterial Attachment, Aggregation, and Alignment on Subcellular Nanogratings. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:4059-4070. [PMID: 29509427 DOI: 10.1021/acs.langmuir.8b00350] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Recent investigations on the interactions of bacteria with micro/nanostructures have revealed a wide range of prokaryotic responses that were previously unknown. Despite these advances, however, it remains unclear how collective bacterial behavior on a surface would be influenced by the presence of anisotropic nanostructures with subcellular dimensions. To clarify this, the attachment, aggregation, and alignment of Pseudomonas aeruginosa on orderly subcellular nanogratings with systematically varied geometries were investigated. Compared with a flat surface, attachment and aggregation of bacteria on the nanogratings were reduced by up to 83 and 84% respectively, whereas alignment increased by a maximum of 850%. Using a semiempirical quantitative model, these results were shown to be caused by a lowering of physicochemical attraction between the substrate and bacteria, possible disruption to cell communication, and physical isolation of bacteria that were entrenched in the nanogratings by capillary action. Furthermore, the bacterial attachment level was generally found to be exponentially related to the contact area between the substrate and bacterial cells, except when there were significant deficits in the available contact area, which prompted the bacterial cells to employ their appendages to maintain a minimum attachment rate. Because the contact area for adhesion is strongly dependent on the geometry of the surface features and orientation of the bacterial cells, these results indicate that the conventional practice of using roughness parameters to draw quantitative relationships between surface topographies and bacterial attachment could suffer from inaccuracies due to the lack of shape and orientation information provided by these parameters. On the basis of these insights, design principles for generating maximal and minimal bacterial attachment on a surface were also proposed and verified with results reported in the literature.
Collapse
Affiliation(s)
- Chang Quan Lai
- Biosystems and Micromechanics , Singapore MIT Alliance for Research and Technology , 1 CREATE Way , Singapore 138602
- Temasek Laboratories , Nanyang Technological University , 50 Nanyang Drive , Singapore 637553
| |
Collapse
|
134
|
Bacterial Surface Spreading Is More Efficient on Nematically Aligned Polysaccharide Substrates. J Bacteriol 2018; 200:JB.00610-17. [PMID: 29311278 DOI: 10.1128/jb.00610-17] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 12/18/2017] [Indexed: 01/07/2023] Open
Abstract
Biofilm-forming bacteria typically deposit layers of polysaccharides on the surfaces they inhabit; hence, polysaccharides are their immediate environment on such surfaces. Previously, we showed that many biofilm-forming bacteria preferentially spread in the direction of aligned and densely packed polysaccharide fibers in compressed substrates, a behavior we referred to as polymertropism. This arrangement of polysaccharide fibers is likely to be similar to that found in the "slime" trails deposited by many biofilm-forming bacteria and would explain previous observations that bacteria tend to follow these trails of polysaccharides. Here, we show that groups of cells or flares spread more rapidly on substrates containing aligned and densely packed polysaccharide fibers. Flares also persist longer, tend to hold their trajectories parallel to the long axes of polysaccharide fibers longer, and ultimately show an increase in displacement away from their origin. On the basis of these findings and others, we propose a model for polymertropism. Namely, we suggest that the packing of the aligned polymers increases the efficiency of surface spreading in the direction of the polymer's long axes; therefore, bacteria tend to spread more rapidly in this direction. Additional work suggests that bacteria can leverage polymertropism, and presumably more efficient surface spreading, for a survival advantage. In particular, when two bacterial species were placed in close proximity and in competition with each other, the ability of one species to move rapidly and directly away from the other by utilizing the aligned polymers of compressed agar substrates led to a clear survival benefit.IMPORTANCE The directed movement of bacteria on compressed substrates was first described in the 1940s and referred to as elasticotaxis (R. Y. Stanier, J Bacteriol 44:405-412, 1942). More recently, this behavior was referred to as polymertropism, as it seems to be a response to the nematic alignment and tight packing of polymers in the substrate (D. J. Lemon, X. Yang, P. Srivastava, Y. Y. Luk, A. G. Garza, Sci Rep 7:7643, 2017, https://doi.org/10.1038/s41598-017-07486-0). The data presented here suggest that bacteria are more efficient at surface spreading when the polymers in the substrate are arranged in this manner. These data also suggest that bacteria can leverage polymertropism, and presumably more efficient surface spreading, for a survival advantage. Namely, one bacterial species was able to use its strong polymertropism response to escape from and survive competition with another species that normally outcompetes it.
Collapse
|
135
|
Martínez-García R, Nadell CD, Hartmann R, Drescher K, Bonachela JA. Cell adhesion and fluid flow jointly initiate genotype spatial distribution in biofilms. PLoS Comput Biol 2018; 14:e1006094. [PMID: 29659578 PMCID: PMC5901778 DOI: 10.1371/journal.pcbi.1006094] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 03/16/2018] [Indexed: 11/18/2022] Open
Abstract
Biofilms are microbial collectives that occupy a diverse array of surfaces. It is well known that the function and evolution of biofilms are strongly influenced by the spatial arrangement of different strains and species within them, but how spatiotemporal distributions of different genotypes in biofilm populations originate is still underexplored. Here, we study the origins of biofilm genetic structure by combining model development, numerical simulations, and microfluidic experiments using the human pathogen Vibrio cholerae. Using spatial correlation functions to quantify the differences between emergent cell lineage segregation patterns, we find that strong adhesion often, but not always, maximizes the size of clonal cell clusters on flat surfaces. Counterintuitively, our model predicts that, under some conditions, investing in adhesion can reduce rather than increase clonal group size. Our results emphasize that a complex interaction between fluid flow and cell adhesiveness can underlie emergent patterns of biofilm genetic structure. This structure, in turn, has an outsize influence on how biofilm-dwelling populations function and evolve.
Collapse
Affiliation(s)
- Ricardo Martínez-García
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Carey D. Nadell
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire, United States of America
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Raimo Hartmann
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Knut Drescher
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
- Department of Physics, Phillips-Universität Marburg, Marburg, Germany
| | - Juan A. Bonachela
- Marine Population Modeling Group, Department of Mathematics and Statistics, University of Strathclyde, Glasgow, Scotland, United Kingdom
- Department of Ecology, Evolution, and Natural Resources, Rutgers University, New Brunswick, New Jersey, United States of America
| |
Collapse
|
136
|
Badura P. Virtual bacterium colony in 3D image segmentation. Comput Med Imaging Graph 2018; 65:152-166. [DOI: 10.1016/j.compmedimag.2017.04.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 04/13/2017] [Accepted: 04/21/2017] [Indexed: 11/16/2022]
|
137
|
Chang YR, Weeks ER, Ducker WA. Surface Topography Hinders Bacterial Surface Motility. ACS APPLIED MATERIALS & INTERFACES 2018; 10:9225-9234. [PMID: 29469562 DOI: 10.1021/acsami.7b16715] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
We demonstrate that the surface motility of the bacterium, Pseudomonas aeruginosa, is hindered by a crystalline hemispherical topography with wavelength in the range of 2-8 μm. The motility was determined by the analysis of time-lapse microscopy images of cells in a flowing growth medium maintained at 37 °C. The net displacement of bacteria over 5 min is much lower on surfaces containing 2-8 μm hemispheres than on flat topography, but displacement on the 1 μm hemispheres is not lower. That is, there is a threshold between 1 and 2 μm for response to the topography. Cells on the 4 μm hemispheres were more likely to travel parallel to the local crystal axis than in other directions. Cells on the 8 μm topography were less likely to travel across the crowns of the hemispheres and were also more likely to make 30°-50° turns than on flat surfaces. These results show that surface topography can act as a significant barrier to surface motility and may therefore hinder surface exploration by bacteria. Because surface exploration can be a part of the process whereby bacteria form colonies and seek nutrients, these results help to elucidate the mechanism by which surface topography hinders biofilm formation.
Collapse
Affiliation(s)
- Yow-Ren Chang
- Department of Chemical Engineering and Center for Soft Matter and Biological Physics , Virginia Tech , Blacksburg , Virginia 24061 , United States
| | - Eric R Weeks
- Department of Physics , Emory University , Atlanta , Georgia 30322 , United States
| | - William A Ducker
- Department of Chemical Engineering and Center for Soft Matter and Biological Physics , Virginia Tech , Blacksburg , Virginia 24061 , United States
| |
Collapse
|
138
|
Ren Y, Wang C, Chen Z, Allan E, van der Mei HC, Busscher HJ. Emergent heterogeneous microenvironments in biofilms: substratum surface heterogeneity and bacterial adhesion force-sensing. FEMS Microbiol Rev 2018; 42:259-272. [DOI: 10.1093/femsre/fuy001] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 01/08/2018] [Indexed: 12/18/2022] Open
Affiliation(s)
- Yijin Ren
- Department of Orthodontics, University of Groningen and University Medical Center Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
| | - Can Wang
- Department of Orthodontics, University of Groningen and University Medical Center Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
- School & Hospital of Stomatology, Wuhan University, Wuhan, 430079, Wuhan, China
| | - Zhi Chen
- School & Hospital of Stomatology, Wuhan University, Wuhan, 430079, Wuhan, China
| | - Elaine Allan
- UCL Eastman Dental Institute, University College London, 256 Gray's Inn Road, London WC1X 8LD, UK
| | - Henny C van der Mei
- Department of Biomedical Engineering, University of Groningen and University Medical Center Groningen, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands
| | - Henk J Busscher
- Department of Biomedical Engineering, University of Groningen and University Medical Center Groningen, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands
| |
Collapse
|
139
|
Stiffness signatures along early stages of Xylella fastidiosa biofilm formation. Colloids Surf B Biointerfaces 2017; 159:174-182. [DOI: 10.1016/j.colsurfb.2017.07.075] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 07/19/2017] [Accepted: 07/26/2017] [Indexed: 01/05/2023]
|
140
|
Abstract
The aim of the research was to study the features of formation of dairy equipment microflora, the ability of microorganisms to form biofilms on the noncorrosive steel surface with the different roughness and to determine the effectiveness of disinfectants. It was established, that bacteria of Bacillus, Lactobacillus genera of Enterobacteriaceae family are most often extracted from the dairy equipment after the sanitary processing by modern disinfectors, in less number of cases – staphylococci, enterococci, streptococci and pseudomonades. Extracted bacteria form mainly biofilms of the high and middle density. In 100 % of cases biofilms of the high density were formed by Bacillus spp. and Enterococcus faecalis bacteria. It indicates the fact that at the disinfection of the dairy equipment, only stable bacteria that have the ability to produce a biofilm of the high density, remain on its surface.
It was established, that the dairy equipment surface relief, namely roughness, has an influence on the process of biofilm formation in Escherichia coli. On the noncorrosive steel surface with the roughness 0,16±0,065 mcm Escherichia coli form biofilms of the lower density comparing with the surface with the density 0,63–0,072 mcm during 24 hours at the temperature 17 °С.
It was established, that working solutions of disinfectants P3-ansep CIP, Eco chlor, Medicarine and Maxidez were more effective as to plankton bacteria. Microorganisms, formed in biofilms, turned out stable to these disinfectants. Most effective disinfectant for the influence on bacteria on biofilms is Р3-oxonia active – 150. So, the obtained data indicate that for the effective sanitary processing of the dairy equipment it is necessary to use disinfectants that influence bacteria in biofilms.
Collapse
|
141
|
Marmont LS, Whitfield GB, Rich JD, Yip P, Giesbrecht LB, Stremick CA, Whitney JC, Parsek MR, Harrison JJ, Howell PL. PelA and PelB proteins form a modification and secretion complex essential for Pel polysaccharide-dependent biofilm formation in Pseudomonas aeruginosa. J Biol Chem 2017; 292:19411-19422. [PMID: 28972168 DOI: 10.1074/jbc.m117.812842] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 09/14/2017] [Indexed: 11/06/2022] Open
Abstract
The pellicle (PEL) polysaccharide is synthesized by the opportunistic pathogen Pseudomonas aeruginosa and is an important biofilm constituent critical for bacterial virulence and persistence. PEL is a cationic polymer that promotes cell-cell interactions within the biofilm matrix through electrostatic interactions with extracellular DNA. Translocation of PEL across the outer membrane is proposed to occur via PelB, a membrane-embedded porin with a large periplasmic domain predicted to contain 19 tetratricopeptide repeats (TPRs). TPR-containing domains are typically involved in protein-protein interactions, and we therefore sought to determine whether PelB serves as a periplasmic scaffold that recruits other components of the PEL secretion apparatus. In this study, we show that the TPR domain of PelB interacts with PelA, an enzyme with PEL deacetylase and hydrolase activities. Structure determination of PelB TPRs 8-11 enabled us to design systematic deletions of individual TPRs and revealed that repeats 9-14, which are required for the cellular localization of PelA with PelB are also essential for PEL-dependent biofilm formation. Copurification experiments indicated that the interaction between PelA and PelB is direct and that the deacetylase activity of PelA increases and its hydrolase activity decreases when these proteins interact. Combined, our results indicate that the TPR-containing domain of PelB localizes PelA to the PEL secretion apparatus within the periplasm and that this may allow for efficient deacetylation of PEL before its export from the cell.
Collapse
Affiliation(s)
- Lindsey S Marmont
- From the Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada.,the Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Gregory B Whitfield
- From the Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada.,the Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Jacquelyn D Rich
- the Department of Biological Sciences, University of Calgary, Calgary, Alberta T2N 1N4, Canada, and
| | - Patrick Yip
- From the Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
| | - Laura B Giesbrecht
- From the Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
| | - Carol A Stremick
- the Department of Biological Sciences, University of Calgary, Calgary, Alberta T2N 1N4, Canada, and
| | - John C Whitney
- From the Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada.,the Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Matthew R Parsek
- the Department of Microbiology, University of Washington, Seattle, Washington 98195-7242
| | - Joe J Harrison
- the Department of Biological Sciences, University of Calgary, Calgary, Alberta T2N 1N4, Canada, and
| | - P Lynne Howell
- From the Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada, .,the Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| |
Collapse
|
142
|
de Anda J, Lee EY, Lee CK, Bennett RR, Ji X, Soltani S, Harrison MC, Baker AE, Luo Y, Chou T, O’Toole GA, Armani AM, Golestanian R, Wong GCL. High-Speed "4D" Computational Microscopy of Bacterial Surface Motility. ACS NANO 2017; 11:9340-9351. [PMID: 28836761 PMCID: PMC5978429 DOI: 10.1021/acsnano.7b04738] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Bacteria exhibit surface motility modes that play pivotal roles in early-stage biofilm community development, such as type IV pili-driven "twitching" motility and flagellum-driven "spinning" and "swarming" motility. Appendage-driven motility is controlled by molecular motors, and analysis of surface motility behavior is complicated by its inherently 3D nature, the speed of which is too fast for confocal microscopy to capture. Here, we combine electromagnetic field computation and statistical image analysis to generate 3D movies close to a surface at 5 ms time resolution using conventional inverted microscopes. We treat each bacterial cell as a spherocylindrical lens and use finite element modeling to solve Maxwell's equations and compute the diffracted light intensities associated with different angular orientations of the bacterium relative to the surface. By performing cross-correlation calculations between measured 2D microscopy images and a library of computed light intensities, we demonstrate that near-surface 3D movies of Pseudomonas aeruginosa translational and rotational motion are possible at high temporal resolution. Comparison between computational reconstructions and detailed hydrodynamic calculations reveals that P. aeruginosa act like low Reynolds number spinning tops with unstable orbits, driven by a flagellum motor with a torque output of ∼2 pN μm. Interestingly, our analysis reveals that P. aeruginosa can undergo complex flagellum-driven dynamical behavior, including precession, nutation, and an unexpected taxonomy of surface motility mechanisms, including upright-spinning bacteria that diffuse laterally across the surface, and horizontal bacteria that follow helicoidal trajectories and exhibit superdiffusive movements parallel to the surface.
Collapse
Affiliation(s)
- Jaime de Anda
- Department of Bioengineering, Department of Chemistry and Biochemistry, and California NanoSystems Institute, University of California Los Angeles, Los Angeles, California 90095-1600, United States
| | - Ernest Y. Lee
- Department of Bioengineering, Department of Chemistry and Biochemistry, and California NanoSystems Institute, University of California Los Angeles, Los Angeles, California 90095-1600, United States
| | - Calvin K. Lee
- Department of Bioengineering, Department of Chemistry and Biochemistry, and California NanoSystems Institute, University of California Los Angeles, Los Angeles, California 90095-1600, United States
| | - Rachel R. Bennett
- Department of Physics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Rudolf Peierls Centre for Theoretical Physics, University of Oxford, Oxford OX1 3NP, U.K
| | - Xiang Ji
- Department of Physics, University of California San Diego, La Jolla, California 92093, United States
| | - Soheil Soltani
- Mork Family Department of Chemical Engineering and Materials Sciences, University of Southern California, Los Angeles, California 90089, United States
| | - Mark C. Harrison
- Mork Family Department of Chemical Engineering and Materials Sciences, University of Southern California, Los Angeles, California 90089, United States
| | - Amy E. Baker
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755, United States
| | - Yun Luo
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755, United States
- DuPont Industrial Biosciences, Wilmington, Delaware 19803, United States
| | - Tom Chou
- Departments of Biomathematics and Mathematics, University of California Los Angeles, Los Angeles, California 90095-1766, United States
| | - George A. O’Toole
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755, United States
| | - Andrea M. Armani
- Mork Family Department of Chemical Engineering and Materials Sciences, University of Southern California, Los Angeles, California 90089, United States
| | - Ramin Golestanian
- Rudolf Peierls Centre for Theoretical Physics, University of Oxford, Oxford OX1 3NP, U.K
| | - Gerard C. L. Wong
- Department of Bioengineering, Department of Chemistry and Biochemistry, and California NanoSystems Institute, University of California Los Angeles, Los Angeles, California 90095-1600, United States
- Corresponding Author: Tel: (310) 794-7684.
| |
Collapse
|
143
|
Jain R, Sliusarenko O, Kazmierczak BI. Interaction of the cyclic-di-GMP binding protein FimX and the Type 4 pilus assembly ATPase promotes pilus assembly. PLoS Pathog 2017; 13:e1006594. [PMID: 28854278 PMCID: PMC5595344 DOI: 10.1371/journal.ppat.1006594] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2016] [Revised: 09/12/2017] [Accepted: 08/21/2017] [Indexed: 01/31/2023] Open
Abstract
Type IVa pili (T4P) are bacterial surface structures that enable motility, adhesion, biofilm formation and virulence. T4P are assembled by nanomachines that span the bacterial cell envelope. Cycles of T4P assembly and retraction, powered by the ATPases PilB and PilT, allow bacteria to attach to and pull themselves along surfaces, so-called “twitching motility”. These opposing ATPase activities must be coordinated and T4P assembly limited to one pole for bacteria to show directional movement. How this occurs is still incompletely understood. Herein, we show that the c-di-GMP binding protein FimX, which is required for T4P assembly in Pseudomonas aeruginosa, localizes to the leading pole of twitching bacteria. Polar FimX localization requires both the presence of T4P assembly machine proteins and the assembly ATPase PilB. PilB itself loses its polar localization pattern when FimX is absent. We use two different approaches to confirm that FimX and PilB interact in vivo and in vitro, and further show that point mutant alleles of FimX that do not bind c-di-GMP also do not interact with PilB. Lastly, we demonstrate that FimX positively regulates T4P assembly and twitching motility by promoting the activity of the PilB ATPase, and not by stabilizing assembled pili or by preventing PilT-mediated retraction. Mutated alleles of FimX that no longer bind c-di-GMP do not allow rapid T4P assembly in these assays. We propose that by virtue of its high-affinity for c-di-GMP, FimX can promote T4P assembly when intracellular levels of this cyclic nucleotide are low. As P. aeruginosa PilB is not itself a high-affinity c-di-GMP receptor, unlike many other assembly ATPases, FimX may play a key role in coupling T4P mediated motility and adhesion to levels of this second messenger. Type IV pili (T4P) are assembled on the surfaces of many bacterial pathogens and commensals through the action of specialized assembly machines whose components and structures are the subject of intense study. Repeated cycles of T4P assembly, attachment and retraction allow bacteria to move or “twitch” along surfaces, efficiently colonize and intoxicate host tissues, and elaborate multicellular structures such as biofilms. Assembly and retraction are powered by specific ATPases, PilB and PilT respectively, but the manner in which their activity is coordinated is still poorly understood. In this work, we provide evidence that a high-affinity c-di-GMP binding protein of Pseudomonas aeruginosa, FimX, interacts with the ATPase PilB and promotes PilB-dependent assembly of T4P. Live cell imaging of twitching bacteria shows that FimX localizes to the leading pole of motile P. aeruginosa and that its recruitment requires both components of the T4P assembly machine and the PilB ATPase. Our work highlights a novel regulatory strategy employed by P. aeruginosa to control assembly of this broadly conserved virulence factor.
Collapse
Affiliation(s)
- Ruchi Jain
- Department of Medicine (Infectious Diseases), Yale University, New Haven, Connecticut, United States of America
| | - Oleksii Sliusarenko
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut, United States of America
| | - Barbara I. Kazmierczak
- Department of Medicine (Infectious Diseases), Yale University, New Haven, Connecticut, United States of America
- Department of Microbial Pathogenesis, Yale University, New Haven, Connecticut, United States of America
- * E-mail:
| |
Collapse
|
144
|
Dade-Robertson M, Keren-Paz A, Zhang M, Kolodkin-Gal I. Architects of nature: growing buildings with bacterial biofilms. Microb Biotechnol 2017; 10:1157-1163. [PMID: 28815998 PMCID: PMC5609236 DOI: 10.1111/1751-7915.12833] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 07/18/2017] [Accepted: 07/18/2017] [Indexed: 12/22/2022] Open
Abstract
In his text 'On Architecture', Vitruvius suggested that architecture is an imitation of nature. Here we discuss what happens when we begin using nature in architecture. We describe recent developments in the study of biofilm structure, and propose combining modern architecture and synthetic microbiology to develop sustainable construction approaches. Recently, Kolodkin-Gal laboratory and others revealed a role for precipitation of calcium carbonate in the maturation and assembly of bacterial communities with complex structures. Importantly, they demonstrated that different secreted organic materials shape the calcium carbonate crystals formed by the bacterial cells. This provides a proof-of-concept for a potential use of bacteria in designing rigid construction materials and altering crystal morphology and function. In this study, we discuss how these recent discoveries may change the current strategies of architecture and construction. We believe that biofilm communities enhanced by synthetic circuits may be used to construct buildings and to sequester carbon dioxide in the process.
Collapse
Affiliation(s)
- Martyn Dade-Robertson
- Faculty of Humanities and Social Sciences, School of Architecture, Planning and Landscape, Newcastle University, Newcastle upon Tyne, UK
| | - Alona Keren-Paz
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Meng Zhang
- Department of Applied Sciences, Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, UK
| | - Ilana Kolodkin-Gal
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| |
Collapse
|
145
|
Lemon DJ, Yang X, Srivastava P, Luk YY, Garza AG. Polymertropism of rod-shaped bacteria: movement along aligned polysaccharide fibers. Sci Rep 2017; 7:7643. [PMID: 28801641 PMCID: PMC5554183 DOI: 10.1038/s41598-017-07486-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 06/16/2017] [Indexed: 01/11/2023] Open
Abstract
In nature, bacteria often live in surface-associated communities known as biofilms. Biofilm-forming bacteria typically deposit a layer of polysaccharide on the surfaces they inhabit; hence, polysaccharide is their immediate environment on many surfaces. In this study, we examined how the physical characteristics of polysaccharide substrates influence the behavior of the biofilm-forming bacterium Myxococcus xanthus. M. xanthus responds to the compression-induced deformation of polysaccharide substrates by preferentially spreading across the surface perpendicular to the axis of compression. Our results suggest that M. xanthus is not responding to the water that accumulates on the surface of the polysaccharide substrate after compression or to compression-induced changes in surface topography such as the formation of troughs. These directed surface movements do, however, consistently match the orientation of the long axes of aligned and tightly packed polysaccharide fibers in compressed substrates, as indicated by behavioral, birefringence and small angle X-ray scattering analyses. Therefore, we suggest that the directed movements are a response to the physical arrangement of the polymers in the substrate and refer to the directed movements as polymertropism. This behavior might be a common property of bacteria, as many biofilm-forming bacteria that are rod-shaped and motile on soft surfaces exhibit polymertropism.
Collapse
Affiliation(s)
- David J Lemon
- Department of Biology, Syracuse University, Syracuse, NY, 13244, United States
| | - Xingbo Yang
- Department of Physics, Syracuse University, Syracuse, NY, 13244, United States.,Department of Physics and Astronomy, Northwestern University, Evanston, IL, 60208, United States
| | - Pragya Srivastava
- Department of Physics, Syracuse University, Syracuse, NY, 13244, United States.,The Francis Crick Institute, London, NW1 1BF, United Kingdom
| | - Yan-Yeung Luk
- Department of Chemistry, Syracuse University, Syracuse, NY, 13244, United States.
| | - Anthony G Garza
- Department of Biology, Syracuse University, Syracuse, NY, 13244, United States.
| |
Collapse
|
146
|
Hill PJ, Scordo JM, Arcos J, Kirkby SE, Wewers MD, Wozniak DJ, Torrelles JB. Modifications of Pseudomonas aeruginosa cell envelope in the cystic fibrosis airway alters interactions with immune cells. Sci Rep 2017; 7:4761. [PMID: 28684799 PMCID: PMC5500645 DOI: 10.1038/s41598-017-05253-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 05/25/2017] [Indexed: 11/10/2022] Open
Abstract
Pseudomonas aeruginosa is a ubiquitous environmental organism and an opportunistic pathogen that causes chronic lung infections in the airways of cystic fibrosis (CF) patients as well as other immune-compromised individuals. During infection, P. aeruginosa enters the terminal bronchioles and alveoli and comes into contact with alveolar lining fluid (ALF), which contains homeostatic and antimicrobial hydrolytic activities, termed hydrolases. These hydrolases comprise an array of lipases, glycosidases, and proteases and thus, they have the potential to modify lipids, carbohydrates and proteins on the surface of invading microbes. Here we show that hydrolase levels between human ALF from healthy and CF patients differ. CF-ALF influences the P. aeruginosa cell wall by reducing the content of one of its major polysaccharides, Psl. This CF-ALF induced Psl reduction does not alter initial bacterial attachment to surfaces but reduces biofilm formation. Importantly, exposure of P. aeruginosa to CF-ALF drives the activation of neutrophils and triggers their oxidative response; thus, defining human CF-ALF as a new innate defense mechanism to control P. aeruginosa infection, but at the same time potentially adding to the chronic inflammatory state of the lung in CF patients.
Collapse
Affiliation(s)
- Preston J Hill
- Department of Microbial Infection and Immunity, College of Medicine, The Ohio State University, Columbus, OH, 43210, USA
| | - Julia M Scordo
- Department of Microbial Infection and Immunity, College of Medicine, The Ohio State University, Columbus, OH, 43210, USA
| | - Jesús Arcos
- Department of Microbial Infection and Immunity, College of Medicine, The Ohio State University, Columbus, OH, 43210, USA
| | - Stephen E Kirkby
- Nationwide Children's Hospital, Section of Pulmonary Medicine, Columbus, OH, 43205, USA.,Department of Internal Medicine, Pulmonary, Critical Care and Sleep Medicine Division, College of Medicine, The Ohio State University, Columbus, OH, 43210, USA
| | - Mark D Wewers
- Department of Internal Medicine, Pulmonary, Critical Care and Sleep Medicine Division, College of Medicine, The Ohio State University, Columbus, OH, 43210, USA.,Center for Microbial Interface Biology, The Ohio State University, Columbus, OH, 43210, USA
| | - Daniel J Wozniak
- Department of Microbial Infection and Immunity, College of Medicine, The Ohio State University, Columbus, OH, 43210, USA. .,Center for Microbial Interface Biology, The Ohio State University, Columbus, OH, 43210, USA. .,Department of Microbiology, The Ohio State University, Columbus, OH, 43210, USA.
| | - Jordi B Torrelles
- Department of Microbial Infection and Immunity, College of Medicine, The Ohio State University, Columbus, OH, 43210, USA. .,Center for Microbial Interface Biology, The Ohio State University, Columbus, OH, 43210, USA.
| |
Collapse
|
147
|
Abstract
Often the view is expressed that water contact angle (WCA) or other wettability/surface energy measurements made on a material surface can be used to predict cellular attachment to materials, e.g., bacteria attach to hydrophobic surfaces. In this article, the authors present a perspective emerging from their work that has failed to find relationships between WCA and microbial and stem cell attachment within large diversity material libraries and compare with the literature concluding that such simple rules are (unfortunately) wholly inadequate to explain cell–material interactions.
Collapse
|
148
|
Role of psl Genes in Antibiotic Tolerance of Adherent Pseudomonas aeruginosa. Antimicrob Agents Chemother 2017; 61:AAC.02587-16. [PMID: 28438927 DOI: 10.1128/aac.02587-16] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 04/15/2017] [Indexed: 11/20/2022] Open
Abstract
Bacteria attached to a surface are generally more tolerant to antibiotics than their planktonic counterparts, even without the formation of a biofilm. The mechanism of antibiotic tolerance in biofilm communities is multifactorial, and the genetic background underlying this antibiotic tolerance has not yet been fully elucidated. Using transposon mutagenesis, we isolated a mutant with reduced tolerance to biapenem (relative to that of the wild type) from adherent cells. Sequencing analysis revealed a mutation in the pslL gene, which is part of the polysaccharide biosynthesis operon. The Pseudomonas aeruginosa PAO1ΔpslBCD mutant demonstrated a 100-fold-lower survival rate during the exposure of planktonic and biofilm cells to biapenem; a similar phenotype was observed in a mouse infection model and in clinical strains. Transcriptional analysis of adherent cells revealed increased expression of both pslA and pelA, which are directly regulated by bis-(3',5')-cyclic dimeric GMP (c-di-GMP). Inactivation of wspF resulted in significantly increased tolerance to biapenem due to increased production of c-di-GMP. The loss of pslBCD in the ΔwspF mutant background abolished the biapenem-tolerant phenotype of the ΔwspF mutant, underscoring the importance of psl in biapenem tolerance. Overexpression of PA2133, which can catalyze the degradation of c-di-GMP, led to a significant reduction in biapenem tolerance in adherent cells, indicating that c-di-GMP is essential in mediating the tolerance effect. The effect of pslBCD on antibiotic tolerance was evident, with 50- and 200-fold-lower survival in the presence of ofloxacin and tobramycin, respectively. We speculate that the psl genes, which are activated by surface adherence through elevated intracellular c-di-GMP levels, confer tolerance to antimicrobials.
Collapse
|
149
|
Abstract
Despite years of research and clinical advances, chronic pulmonary infections with mucoid Pseudomonas aeruginosa remain the primary concern for cystic fibrosis patients. Much of the research on these strains has focused on the contributions of the polysaccharide alginate; however, it is becoming evident that the neutral polysaccharide Psl also contributes to biofilm formation and the maintenance of chronic infections. Here, we demonstrate that Psl produced by mucoid strains has significant roles in biofilm structure and evasion of immune effectors. Though mucoid strains produce less Psl than nonmucoid strains, the Psl that is produced is functional, since it mediates adhesion to human airway cells and epithelial cell death. Additionally, Psl protects mucoid bacteria from opsonization and killing by complement components in human serum. Psl production by mucoid strains stimulates a proinflammatory response in the murine lung, leading to reduced colonization. To determine the relevance of these data to clinical infections, we tested Psl production and biofilm formation of a panel of mucoid clinical isolates. We demonstrated three classes of mucoid isolates, those that produce Psl and form robust biofilms, those that did not produce Psl and have a poor biofilm phenotype, and exopolysaccharide (EPS) redundant strains. Collectively, these experimental results demonstrate that Psl contributes to the biofilm formation and immune evasion of many mucoid strains. This is a novel role for Psl in the establishment and maintenance of chronic pulmonary infections by mucoid strains. Cystic fibrosis patients are engaged in an ongoing battle against chronic lung infections by the bacterium Pseudomonas aeruginosa. One key factor contributing to the maintenance of chronic infections is the conversion to a mucoid phenotype, where the bacteria produce copious amounts of the polysaccharide alginate. Once the bacteria become mucoid, existing treatments are poorly effective. We proposed that mucoid bacteria produce an additional polysaccharide, Psl, which is important for their establishment and maintenance of chronic infections. This work demonstrates that Psl enhances attachment of mucoid bacteria to lung surfaces and leads to inflammation and damage in the lung. Additionally, we find that 50% of mucoid bacteria isolated from patients with chronic infections rely on Psl for the structure of their biofilm communities, suggesting that treatments against Psl should be investigated to enhance the success of current therapies.
Collapse
|
150
|
de Haan HW. Modeling and Simulating the Dynamics of Type IV Pili Extension of Pseudomonas aeruginosa. Biophys J 2017; 111:2263-2273. [PMID: 27851948 DOI: 10.1016/j.bpj.2016.09.050] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 09/13/2016] [Accepted: 09/29/2016] [Indexed: 01/10/2023] Open
Abstract
Bacteria such as Pseudomonas aeruginosa use type IV pili to move across surfaces. The pili extend, attach to the surface, and then retract to move the bacteria forward. In this article, a coarse-grained model of pilus extension and attachment is developed. Simulations performed at biologically relevant conditions indicate that pilus extension is a quasistatic process such that the pili are able to relax via thermal fluctuations as it is being built and extended. Results are generated for pili with different rigidities ranging from very flexible to very stiff. It is shown that very flexible pili do not extend very far and thus would limit the bacteria to short jumps forward while stiff pili enable much greater displacements. Feasible mechanisms of attachment to the surface are also found to vary greatly between flexible and stiff pili. While it is not always the tip of flexible pili that first makes contact with the substrate, it is likely to be a part of the pili that is close to the tip. Conversely, stiff pili are much more likely to make contact with the substrate via the tip, but if not then the part of the pilus that attaches can be quite far from the tip. These results thus give insight to help resolve current discrepancies in the literature regarding pilus stiffness and the location of adhesins on pili.
Collapse
Affiliation(s)
- Hendrick W de Haan
- Faculty of Science, University of Ontario Institute of Technology, Oshawa, Ontario, Canada.
| |
Collapse
|