1
|
Schiller H, Hong Y, Kouassi J, Rados T, Kwak J, DiLucido A, Safer D, Marchfelder A, Pfeiffer F, Bisson A, Schulze S, Pohlschroder M. Identification of structural and regulatory cell-shape determinants in Haloferax volcanii. Nat Commun 2024; 15:1414. [PMID: 38360755 PMCID: PMC10869688 DOI: 10.1038/s41467-024-45196-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 01/16/2024] [Indexed: 02/17/2024] Open
Abstract
Archaea play indispensable roles in global biogeochemical cycles, yet many crucial cellular processes, including cell-shape determination, are poorly understood. Haloferax volcanii, a model haloarchaeon, forms rods and disks, depending on growth conditions. Here, we used a combination of iterative proteomics, genetics, and live-cell imaging to identify mutants that only form rods or disks. We compared the proteomes of the mutants with wild-type cells across growth phases, thereby distinguishing between protein abundance changes specific to cell shape and those related to growth phases. The results identified a diverse set of proteins, including predicted transporters, transducers, signaling components, and transcriptional regulators, as important for cell-shape determination. Through phenotypic characterization of deletion strains, we established that rod-determining factor A (RdfA) and disk-determining factor A (DdfA) are required for the formation of rods and disks, respectively. We also identified structural proteins, including an actin homolog that plays a role in disk-shape morphogenesis, which we named volactin. Using live-cell imaging, we determined volactin's cellular localization and showed its dynamic polymerization and depolymerization. Our results provide insights into archaeal cell-shape determination, with possible implications for understanding the evolution of cell morphology regulation across domains.
Collapse
Affiliation(s)
- Heather Schiller
- University of Pennsylvania, Department of Biology, Philadelphia, PA, 19104, USA
| | - Yirui Hong
- University of Pennsylvania, Department of Biology, Philadelphia, PA, 19104, USA
| | - Joshua Kouassi
- University of Pennsylvania, Department of Biology, Philadelphia, PA, 19104, USA
| | - Theopi Rados
- Brandeis University, Department of Biology, Waltham, MA, 02453, USA
| | - Jasmin Kwak
- Brandeis University, Department of Biology, Waltham, MA, 02453, USA
| | - Anthony DiLucido
- University of Pennsylvania, Department of Biology, Philadelphia, PA, 19104, USA
| | - Daniel Safer
- University of Pennsylvania, Department of Physiology, Philadelphia, PA, 19104, USA
| | | | - Friedhelm Pfeiffer
- Biology II, Ulm University, 89069, Ulm, Germany
- Computational Biology Group, Max Planck Institute of Biochemistry, 82152, Martinsried, Germany
| | - Alexandre Bisson
- Brandeis University, Department of Biology, Waltham, MA, 02453, USA.
| | - Stefan Schulze
- University of Pennsylvania, Department of Biology, Philadelphia, PA, 19104, USA.
- Rochester Institute of Technology, Thomas H. Gosnell School of Life Sciences, Rochester, NY, 14623, USA.
| | | |
Collapse
|
2
|
Kalia M, Amari D, Davies DG, Sauer K. cis-DA-dependent dispersion by Pseudomonas aeruginosa biofilm and identification of cis-DA-sensory protein DspS. mBio 2023; 14:e0257023. [PMID: 38014955 PMCID: PMC10746223 DOI: 10.1128/mbio.02570-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 10/11/2023] [Indexed: 11/29/2023] Open
Abstract
IMPORTANCE Dispersion is an essential stage of the biofilm life cycle resulting in the release of bacteria from a biofilm into the surrounding environment. Dispersion contributes to bacterial survival by relieving overcrowding within a biofilm and allowing dissemination of cells into new habitats for colonization. Thus, dispersion can contribute to biofilm survival as well as disease progression and transmission. Cells dispersed from a biofilm rapidly lose their recalcitrant antimicrobial-tolerant biofilm phenotype and transition to a state that is susceptible to antibiotics. However, much of what is known about this biofilm developmental stage has been inferred from exogenously induced dispersion. Our findings provide the first evidence that native dispersion is coincident with reduced cyclic dimeric guanosine monophosphate levels, while also relying on at least some of the same factors that are central to the environmentally induced dispersion response, namely, BdlA, DipA, RbdA, and AmrZ. Additionally, we demonstrate for the first time that cis-DA signaling to induce dispersion is attributed to the two-component sensor/response regulator DspS, a homolog of the DSF sensor RpfC. Our findings also provide a path toward manipulating the native dispersion response as a novel and highly promising therapeutic intervention.
Collapse
Affiliation(s)
- Manmohit Kalia
- Department of Biological Sciences, Binghamton University, Binghamton, New York, USA
- Binghamton Biofilm Research Center, Binghamton University, Binghamton, New York, USA
| | - Diana Amari
- Department of Biological Sciences, Binghamton University, Binghamton, New York, USA
- Binghamton Biofilm Research Center, Binghamton University, Binghamton, New York, USA
| | - David G. Davies
- Department of Biological Sciences, Binghamton University, Binghamton, New York, USA
- Binghamton Biofilm Research Center, Binghamton University, Binghamton, New York, USA
| | - Karin Sauer
- Department of Biological Sciences, Binghamton University, Binghamton, New York, USA
- Binghamton Biofilm Research Center, Binghamton University, Binghamton, New York, USA
| |
Collapse
|
3
|
Segura A, Molina L. LuxR402 of Novosphingobium sp. HR1a regulates the correct configuration of cell envelopes. Front Microbiol 2023; 14:1205860. [PMID: 37577419 PMCID: PMC10413115 DOI: 10.3389/fmicb.2023.1205860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 07/10/2023] [Indexed: 08/15/2023] Open
Abstract
Although there is some evidence to suggest that LuxR-solo proteins participate in inter-species or even inter-kingdom communication, most of the LuxR-solo protein functions are unknown. We have characterized the LuxR402 regulator of Novosphingobium sp. HR1a, a bacterial strain with the ability to establish high numbers in the plant rhizosphere and able to degrade a wide range of polycyclic aromatic hydrocarbons. LuxR402 controls the aggregation state of the bacterial culture; cultures of a mutant strain lacking this regulator flocculate in less than 3 h without agitation. We have demonstrated that the bacterial surface of the mutant is highly hydrophobic and that the mutant cells assimilate sugars slower than the wild-type. The flocculation mechanism has been demonstrated to be involved in the survival of the strain under unfavorable conditions; the luxR402 gene is repressed and produces flocculation in the presence of salicylate, a substrate that, although being assimilated by Novosphingobium, is toxic to cells at high concentrations. The flocculation of cultures in industrial setups has mainly been achieved through the addition of chemicals; these studies open up the possibility of controlling the flocculation by regulating the level of expression of the luxR402 gene.
Collapse
Affiliation(s)
| | - Lázaro Molina
- Environmental Protection Department, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| |
Collapse
|
4
|
Saleh DO, Horstmann JA, Giralt-Zúñiga M, Weber W, Kaganovitch E, Durairaj AC, Klotzsch E, Strowig T, Erhardt M. SPI-1 virulence gene expression modulates motility of Salmonella Typhimurium in a proton motive force- and adhesins-dependent manner. PLoS Pathog 2023; 19:e1011451. [PMID: 37315106 DOI: 10.1371/journal.ppat.1011451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 06/01/2023] [Indexed: 06/16/2023] Open
Abstract
Both the bacterial flagellum and the evolutionary related injectisome encoded on the Salmonella pathogenicity island 1 (SPI-1) play crucial roles during the infection cycle of Salmonella species. The interplay of both is highlighted by the complex cross-regulation that includes transcriptional control of the flagellar master regulatory operon flhDC by HilD, the master regulator of SPI-1 gene expression. Contrary to the HilD-dependent activation of flagellar gene expression, we report here that activation of HilD resulted in a dramatic loss of motility, which was dependent on the presence of SPI-1. Single cell analyses revealed that HilD-activation triggers a SPI-1-dependent induction of the stringent response and a substantial decrease in proton motive force (PMF), while flagellation remains unaffected. We further found that HilD activation enhances the adhesion of Salmonella to epithelial cells. A transcriptome analysis revealed a simultaneous upregulation of several adhesin systems, which, when overproduced, phenocopied the HilD-induced motility defect. We propose a model where the SPI-1-dependent depletion of the PMF and the upregulation of adhesins upon HilD-activation enable flagellated Salmonella to rapidly modulate their motility during infection, thereby enabling efficient adhesion to host cells and delivery of effector proteins.
Collapse
Affiliation(s)
- Doaa Osama Saleh
- Institute for Biology/Molecular Microbiology, Humboldt-Universität zu Berlin, Berlin, Germany
- Department of Microbiology and Immunology, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt
| | - Julia A Horstmann
- Junior Research Group Infection Biology of Salmonella, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - María Giralt-Zúñiga
- Institute for Biology/Molecular Microbiology, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Willi Weber
- Institute for Biology, Experimental Biophysics/Mechanobiology, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Eugen Kaganovitch
- Max Planck Institute for Terrestrial Microbiology and Center for Synthetic Microbiology (SYNMIKRO), Marburg, Germany
| | - Abilash Chakravarthy Durairaj
- Junior Research Group Infection Biology of Salmonella, Helmholtz Centre for Infection Research, Braunschweig, Germany
- Department of Microbial Immune Regulation, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Enrico Klotzsch
- Institute for Biology, Experimental Biophysics/Mechanobiology, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Till Strowig
- Department of Microbial Immune Regulation, Helmholtz Centre for Infection Research, Braunschweig, Germany
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany
| | - Marc Erhardt
- Institute for Biology/Molecular Microbiology, Humboldt-Universität zu Berlin, Berlin, Germany
- Max Planck Unit for the Science of Pathogens, Berlin, Germany
| |
Collapse
|
5
|
Laboratory Grown Biofilms of Bacteria Associated with Human Atherosclerotic Carotid Arteries Release Collagenases and Gelatinases during Iron-Induced Dispersion. Microbiol Spectr 2022; 10:e0100121. [PMID: 35543563 PMCID: PMC9241811 DOI: 10.1128/spectrum.01001-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The association of bacteria with arterial plaque lesions in patients with atherosclerosis has been widely reported. However, the role these bacteria play in the progression of atherosclerosis is still unclear. Previous work in our lab has demonstrated that bacteria exist in carotid artery plaques as biofilm deposits. Biofilms are communities of microorganisms enmeshed within a protective, self-produced extracellular matrix and have been shown to contribute to chronic infections in humans. Biofilm communities have the potential to impact surrounding tissues in an infection if they undergo a dispersion response, releasing bacteria into the surrounding environment by enzymatic degradation of the extracellular matrix. One concern relating to these enzymes is that they could cause collateral damage to host tissues. In this study, we present an in vitro multispecies biofilm culturing model used to investigate the potential role of bacterial biofilm dispersion in the progression of atherosclerosis. This work has demonstrated an increase in cell release from mixed-species biofilms formed by bacteria associated with human carotid arterial plaque deposits following treatment with iron or a combination of norepinephrine and transferrin. Greater extracellular lipase, protease, and collagenase/gelatinase activity was also associated with iron-treated biofilms. The results of this work suggest that bacteria in this model undergo iron-induced biofilm dispersion, as evidenced by the increased cell release and higher enzyme activity following treatment. This work demonstrates the potential for multispecies biofilm dispersion to contribute to arterial tissue degradation by bacteria and suggests that in atherosclerotic infections, biofilm dispersion may contribute to thrombogenesis, which can lead to heart attack or stroke. IMPORTANCE Atherosclerosis, or hardening of the arteries, is a leading cause of congestive heart failure, heart attack, and stroke in humans. Mounting evidence, in the literature and from our lab, points to the regular involvement of bacteria within arterial plaque deposits in patients with advanced atherosclerosis. Very little is known about the behavior of these bacteria and whether they may contribute to tissue damage in infected arteries. Tissue damage within the arterial plaque lesion can lead to rupture of the plaque contents into the bloodstream, where a clot may form, resulting in a potential heart attack or stroke. This study shows that plaque-associated bacteria, when cultured as mixed-species biofilms in the laboratory, can release degradative enzymes into their environment as the result of a dispersion response triggered by iron. These degradative enzymes can digest proteins and lipids which are associated with the tissues that separate the plaque lesion from the arterial lumen. Thus, this study demonstrates that if mixed species biofilms are induced to undergo dispersion in an infected atherosclerotic lesion when exposed to an elevated concentration of free iron, they have the potential to contribute to the weakening of arterial tissues, which may contribute to atherosclerotic plaque destabilization.
Collapse
|
6
|
Luo A, Wang F, Sun D, Liu X, Xin B. Formation, Development, and Cross-Species Interactions in Biofilms. Front Microbiol 2022; 12:757327. [PMID: 35058893 PMCID: PMC8764401 DOI: 10.3389/fmicb.2021.757327] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 11/29/2021] [Indexed: 12/25/2022] Open
Abstract
Biofilms, which are essential vectors of bacterial survival, protect microbes from antibiotics and host immune attack and are one of the leading causes that maintain drug-resistant chronic infections. In nature, compared with monomicrobial biofilms, polymicrobial biofilms composed of multispecies bacteria predominate, which means that it is significant to explore the interactions between microorganisms from different kingdoms, species, and strains. Cross-microbial interactions exist during biofilm development, either synergistically or antagonistically. Although research into cross-species biofilms remains at an early stage, in this review, the important mechanisms that are involved in biofilm formation are delineated. Then, recent studies that investigated cross-species cooperation or synergy, competition or antagonism in biofilms, and various components that mediate those interactions will be elaborated. To determine approaches that minimize the harmful effects of biofilms, it is important to understand the interactions between microbial species. The knowledge gained from these investigations has the potential to guide studies into microbial sociality in natural settings and to help in the design of new medicines and therapies to treat bacterial infections.
Collapse
Affiliation(s)
- Aihua Luo
- Department of Stomatology, Guizhou Provincial People's Hospital, Guiyang, China
| | - Fang Wang
- Department of Pharmacy, Qingdao Stomatological Hospital Affiliated to Qingdao University, Qingdao, China
| | - Degang Sun
- Department of Cariology and Endodontology, Qingdao Stomatological Hospital Affiliated to Qingdao University, Qingdao, China
| | - Xueyu Liu
- Department of Cariology and Endodontology, Qingdao Stomatological Hospital Affiliated to Qingdao University, Qingdao, China.,Central Laboratory, Qingdao Stomatological Hospital Affiliated to Qingdao University, Qingdao, China
| | - Bingchang Xin
- Department of Cariology and Endodontology, Qingdao Stomatological Hospital Affiliated to Qingdao University, Qingdao, China.,Central Laboratory, Qingdao Stomatological Hospital Affiliated to Qingdao University, Qingdao, China
| |
Collapse
|
7
|
Niu A, Bian WP, Feng SL, Pu SY, Wei XY, Yang YF, Song LY, Pei DS. Role of manganese superoxide dismutase (Mn-SOD) against Cr(III)-induced toxicity in bacteria. JOURNAL OF HAZARDOUS MATERIALS 2021; 403:123604. [PMID: 32781281 DOI: 10.1016/j.jhazmat.2020.123604] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Revised: 07/21/2020] [Accepted: 07/28/2020] [Indexed: 06/11/2023]
Abstract
The toxicity of Cr(VI) was widely investigated, but the defense mechanism against Cr(III) in bacteria are seldom reported. Here, we found that Cr(III) inhibited bacterial growth and induced reactive oxygen species (ROS). After exposure to Cr(III), loss of sodA not only led to the excessive generation of ROS, but also enhanced the level of lipid peroxidation and reduced the GSH level, indicating that the deficiency of Mn-SOD decreased the bacterial resistance ability against Cr(III). The adverse effects of oxidative stress caused by Cr(III) could be recovered by the rescue of Mn-SOD in the sodA-deficient strain. Besides the oxidative stress, Cr(III) could cause the bacterial morphology variation, which was distinct between the wild-type and the sodA-deficient strains due to the differential expressions of Z-ring division genes. Moreover, Mn-SOD might prevent Cr(III) from oxidation on the bacterial surface by combining with Cr(III). Taken together, our results indicated that the Mn-SOD played a vital role in regulating the stress resistance, expression of cell division-related genes, bacterial morphology, and chemistry valence state of Cr. Our findings firstly provided a more in-depth understanding of Cr(III) toxicity and bacterial defense mechanism against Cr(III).
Collapse
Affiliation(s)
- Aping Niu
- Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, China; College of Resources and Environmental Engineering, Guizhou University, Guizhou, 550025, China
| | - Wan-Ping Bian
- Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, China
| | - Shuang-Long Feng
- Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, China
| | - Shi-Ya Pu
- Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xing-Yi Wei
- Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, China; School of River and Ocean Engineering, Chongqing Jiaotong University, Chongqing 400074, China
| | - Yi-Fan Yang
- Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, China; College of Life Science, Henan Normal University, Xinxiang, 453007, China
| | - Li-Yan Song
- Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, China
| | - De-Sheng Pei
- Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, China; College of Life Science, Henan Normal University, Xinxiang, 453007, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
| |
Collapse
|
8
|
Gentile G, Maimone G, La Ferla R, Azzaro M, Catalfamo M, Genovese M, Santisi S, Maldani M, Macrì A, Cappello S. Phenotypic Variations of Oleispira antarctica RB-8(T) in Different Growth Conditions. Curr Microbiol 2020; 77:3414-3421. [PMID: 32740715 DOI: 10.1007/s00284-020-02143-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 07/22/2020] [Indexed: 12/30/2022]
Abstract
The peculiar biotechnological applications of Oleispira spp. in the natural cleansing of oil-polluted marine systems stimulated the study of the phenotypic characteristics of the Oleispira antarctica RB-8(T) strain and modifications of these characteristics in relation to different growth conditions. Bacterial abundance, cell size and morphology variations (by image analysis) and hydrocarbon degradation (by gas chromatography with flame ionization detection, GC-FID) were analysed in different cultures of O. antarctica RB-8(T). The effects of six different hydrocarbon mixtures (diesel, engine oil, naval oil waste, bilge water, jet fuel and oil) used as a single carbon source combined with two different growth temperatures (4° and 15 °C) were analysed (for 22 days). The data obtained showed that the mean cell volume decreased with increasing experimental temperature. Three morphological bacterial shapes were identified: spirals, rods and cocci. Morphological transition from spiral to rod and coccoid shapes in relation to the different substrates (oil mixtures) and/or growth temperatures was observed, except for one experimental condition (naval oil waste) in which spiral bacteria were mostly dominant. Phenotypic traits and physiological status of hydrocarbon-degrading bacteria showed important modifications in relation to culture conditions. These findings suggest interesting potential for strain RB-8(T) for ecological and applicative purposes.
Collapse
Affiliation(s)
- Gabriella Gentile
- Institute for Biological Resource and Marine Biotechnology (IRBIM), CNR of Messina, Spianata S. Raineri 86, 98122, Messina, Italy
| | - Giovanna Maimone
- Institute of Polar Sciences (ISP), CNR of Messina, Spianata S. Raineri 86, 98122, Messina, Italy.
| | - Rosabruna La Ferla
- Institute of Polar Sciences (ISP), CNR of Messina, Spianata S. Raineri 86, 98122, Messina, Italy
| | - Maurizio Azzaro
- Institute of Polar Sciences (ISP), CNR of Messina, Spianata S. Raineri 86, 98122, Messina, Italy
| | - Maurizio Catalfamo
- Institute for Biological Resource and Marine Biotechnology (IRBIM), CNR of Messina, Spianata S. Raineri 86, 98122, Messina, Italy
| | - Maria Genovese
- Institute for Biological Resource and Marine Biotechnology (IRBIM), CNR of Messina, Spianata S. Raineri 86, 98122, Messina, Italy
| | - Santina Santisi
- Institute for Biological Resource and Marine Biotechnology (IRBIM), CNR of Messina, Spianata S. Raineri 86, 98122, Messina, Italy.,Institute of Applied Sciences and Intelligent Systems, Eduardo Caianello" (ISASI), CNR of Messina, 98122, Messina, Italy
| | - Mohamed Maldani
- Environment & Soil Microbiology Unit, Faculty of Sciences, Moulay Ismail University, Meknes, Morocco
| | - Angela Macrì
- Institute for Biological Resource and Marine Biotechnology (IRBIM), CNR of Messina, Spianata S. Raineri 86, 98122, Messina, Italy.,Faculty of Sciences, University of Messina, Messina, Italy
| | - Simone Cappello
- Institute for Biological Resource and Marine Biotechnology (IRBIM), CNR of Messina, Spianata S. Raineri 86, 98122, Messina, Italy
| |
Collapse
|
9
|
Machineni L. Effects of biotic and abiotic factors on biofilm growth dynamics and their heterogeneous response to antibiotic challenge. J Biosci 2020. [DOI: 10.1007/s12038-020-9990-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
|
10
|
Machineni L. Effects of biotic and abiotic factors on biofilm growth dynamics and their heterogeneous response to antibiotic challenge. J Biosci 2020; 45:25. [PMID: 32020907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Over the last couple of decades, with the crisis of new antimicrobial arsenal, multidrug-resistant clinical pathogens have been observed extensively. In clinical and medical settings, these persistent pathogens predominantly grow as complex heterogeneous structures enmeshed in a self-produced exopolysaccharide matrix, termed as biofilms. Since biofilms can rapidly form by adapting new environmental surroundings and have potential effect on human health, it is critical to study them promptly and consistently. Biofilm infections are challenging in the contamination of medical devices and implantations, food processing and pharmaceutical industrial settings, and in dental area caries, periodontitis and so on. The persistence of infections associated with biofilms has been mainly attributed to the increased antibiotic resistance offered by the cells growing in biofilms. In fact, it is well known that this recalcitrance of bacterial biofilms is multifactorial, and there are several resistance mechanisms that may act in parallel in order to provide an enhanced level of resistance to the biofilm. In combination, distinct resistance mechanisms significantly decrease our ability to control and eradicate biofilm-associated infections with current antimicrobial arsenal. In addition, various factors are known to influence the process of biofilm formation, growth dynamics, and their heterogeneous response towards antibiotic therapy. The current review discusses the contribution of cellular and physiochemical factors on the growth dynamics of biofilm, especially their role in antibiotic resistance mechanisms of bacterial population living in surface attached growth mode. A systematic investigation on the effects and treatment of biofilms may pave the way for novel therapeutic strategies to prevent and treat biofilms in healthcare and industrial settings.
Collapse
|
11
|
Lonergan ZR, Skaar EP. Nutrient Zinc at the Host-Pathogen Interface. Trends Biochem Sci 2019; 44:1041-1056. [PMID: 31326221 PMCID: PMC6864270 DOI: 10.1016/j.tibs.2019.06.010] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 06/13/2019] [Accepted: 06/25/2019] [Indexed: 12/12/2022]
Abstract
Zinc is an essential cofactor required for life and, as such, mechanisms exist for its homeostatic maintenance in biological systems. Despite the evolutionary distance between vertebrates and microbial life, there are parallel mechanisms to balance the essentiality of zinc with its inherent toxicity. Vertebrates regulate zinc homeostasis through a complex network of metal transporters and buffering systems that respond to changes in nutritional zinc availability or inflammation. Fine-tuning of this network becomes crucial during infections, where host nutritional immunity attempts to limit zinc availability to pathogens. However, accumulating evidence demonstrates that pathogens have evolved mechanisms to subvert host-mediated zinc withholding, and these metal homeostasis systems are important for survival within the host. We discuss here the mechanisms of vertebrate and bacterial zinc homeostasis and mobilization, as well as recent developments in our understanding of microbial zinc acquisition.
Collapse
Affiliation(s)
- Zachery R Lonergan
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA; Microbe-Host Interactions Training Program, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Eric P Skaar
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA; Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA.
| |
Collapse
|
12
|
Liu J, Li B, Wang Y, Zhang G, Jiang X, Li X. Passage and community changes of filterable bacteria during microfiltration of a surface water supply. ENVIRONMENT INTERNATIONAL 2019; 131:104998. [PMID: 31330365 DOI: 10.1016/j.envint.2019.104998] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 07/06/2019] [Accepted: 07/07/2019] [Indexed: 06/10/2023]
Abstract
The omnipresence of filterable bacteria that can pass through 0.22-μm membrane filters demands a change in the sterile filtration practice. In this study, we identified that filterable bacteria enriched from a surface water are members of the Bacteroidetes, Proteobacteria, Spirochaetae, Firmicutes, and Actinobacteria. Filterable bacteria displayed superior filterability during the entire bacterial growth phase, especially at the exponential phase. Maximal passage percentages were comparable at different cell densities, and achieved earlier at high cell density. Furthermore, filter retention for the investigated bacteria is independent of liquid temperature. However, cultivation temperature could affect the growth of some specific filterable bacteria and lead to variability in the passage percentage. Additionally, membrane materials, pore size and filtering flux greatly affected the passage of filterable bacteria. The majority of filterable Hylemonella and SAR324 could pass through 0.1-μm polyvinylidene fluoride and polyethersulfone filters but could not pass through 0.1-μm polycarbonate and mixed cellulose esters filters. Taken together, our results demonstrated that the ultra-small size of filterable bacteria, membrane characteristics and filtration operational conditions could challenge the validity of the 0.22/0.1-μm sterilizing grade filters in providing bio-safety barriers.
Collapse
Affiliation(s)
- Jie Liu
- Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety, Graduate School at Shenzhen, Tsinghua University, China
| | - Bing Li
- Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety, Graduate School at Shenzhen, Tsinghua University, China.
| | - Yingying Wang
- College of Environmental Science and Engineering, Nankai University, China
| | - Guijuan Zhang
- Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety, Graduate School at Shenzhen, Tsinghua University, China
| | - Xiaotao Jiang
- Environmental Biotechnology Laboratory, The University of Hong Kong, Hong Kong, China
| | - Xiaoyan Li
- Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety, Graduate School at Shenzhen, Tsinghua University, China; Tsinghua-Berkeley Shenzhen Institute, Tsinghua University, Shenzhen, China.
| |
Collapse
|
13
|
Siebdrath N, Farhat N, Ding W, Kruithof J, Vrouwenvelder JS. Impact of membrane biofouling in the sequential development of performance indicators: Feed channel pressure drop, permeability, and salt rejection. J Memb Sci 2019. [DOI: 10.1016/j.memsci.2019.05.043] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
14
|
Zhu C, Chen J, Wang Y, Wang L, Guo X, Chen N, Zheng P, Sun J, Ma Y. Enhancing 5-aminolevulinic acid tolerance and production by engineering the antioxidant defense system of Escherichia coli. Biotechnol Bioeng 2019; 116:2018-2028. [PMID: 30934113 DOI: 10.1002/bit.26981] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 03/03/2019] [Accepted: 03/28/2019] [Indexed: 01/06/2023]
Abstract
5-Aminolevulinic acid (ALA) is a value-added compound with potential applications in the fields of agriculture and medicine. Although massive efforts have recently been devoted to building microbial producers of ALA through metabolic engineering, few studies focused on the cellular response and tolerance to ALA. In this study, we demonstrated that ALA caused severe cell damage and morphology change of Escherichia coli via generating reactive oxygen species (ROS), which were further determined to be mainly hydrogen peroxide and superoxide anion radical. ALA treatment activated the native antioxidant defense system by upregulating catalase (CAT) and superoxide dismutase (SOD) expression to combat ROS. Further overexpressing CAT (encoded by katG and katE) and SOD (encoded by sodA, sodB, and sodC) not only improved ALA tolerance but also its production level. Notably, coexpression of katE and sodB in an ALA synthase expressing strain enhanced the biomass and final ALA titer by 81% and 117% (11.5 g/L) in a 5 L bioreactor, respectively. This study demonstrates the importance of tolerance engineering in strain development. Reinforcing the antioxidant defense system holds promise to improve the bioproduction of chemicals that cause oxidative stress.
Collapse
Affiliation(s)
- Chengchao Zhu
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China.,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, China.,Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Jiuzhou Chen
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, China.,Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Yu Wang
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, China.,Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Lixian Wang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Xuan Guo
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, China.,Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Ning Chen
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Ping Zheng
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, China.,Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Jibin Sun
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, China.,Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Yanhe Ma
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| |
Collapse
|
15
|
Farhat NM, Javier L, Van Loosdrecht MCM, Kruithof JC, Vrouwenvelder JS. Role of feed water biodegradable substrate concentration on biofouling: Biofilm characteristics, membrane performance and cleanability. WATER RESEARCH 2019; 150:1-11. [PMID: 30508707 DOI: 10.1016/j.watres.2018.11.054] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2018] [Revised: 10/25/2018] [Accepted: 11/19/2018] [Indexed: 06/09/2023]
Abstract
Biofouling severely impacts operational performance of membrane systems increasing the cost of water production. Understanding the effect of critical parameters of feed water such as biodegradable substrate concentration on the developed biofilm characteristics enables development of more effective biofouling control strategies. In this study, the effect of substrate concentration on the biofilm characteristics was examined using membrane fouling simulators (MFSs). A feed channel pressure drop (PD) increase of 200 mbar was used as a benchmark to study the developed biofilm. The amount and characteristics of the formed biofilm were analysed in relation to membrane performance indicators: feed channel pressure drop and permeate flux. The effect of the characteristics of the biofilm developed at three substrate concentrations on the removal efficiency of the different biofilms was evaluated applying acid/base cleaning. Results showed that a higher feed water substrate concentration caused a higher biomass amount, a faster PD increase, but a lower permeate flux decline. The permeate flux decline was affected by the spatial location and the physical characteristics of the biofilm rather than the total amount of biofilm. The slower growing biofilm developed at the lowest substrate concentration was harder to remove by NaOH/HCl cleanings than the biofilm developed at the higher substrate concentrations. Effective biofilm removal is essential to prevent a fast biofilm regrowth after cleaning. While substrate limitation is a generally accepted biofouling control strategy delaying biofouling, development of advanced cleaning methods to remove biofilms formed under substrate limited conditions is of paramount importance.
Collapse
Affiliation(s)
- N M Farhat
- King Abdullah University of Science and Technology (KAUST), Water Desalination and Reuse Center (WDRC), Division of Biological and Environmental Science and Engineering (BESE), Thuwal, 23955-6900, Saudi Arabia.
| | - L Javier
- King Abdullah University of Science and Technology (KAUST), Water Desalination and Reuse Center (WDRC), Division of Biological and Environmental Science and Engineering (BESE), Thuwal, 23955-6900, Saudi Arabia
| | - M C M Van Loosdrecht
- Delft University of Technology, Faculty of Applied Sciences, Department of Biotechnology, Van der Maasweg 9, 2629, HZ, Delft, the Netherlands
| | - J C Kruithof
- Wetsus, European Centre of Excellence for Sustainable Water Technology, Oostergoweg 9, 8911, MA, Leeuwarden, the Netherlands
| | - J S Vrouwenvelder
- King Abdullah University of Science and Technology (KAUST), Water Desalination and Reuse Center (WDRC), Division of Biological and Environmental Science and Engineering (BESE), Thuwal, 23955-6900, Saudi Arabia; Delft University of Technology, Faculty of Applied Sciences, Department of Biotechnology, Van der Maasweg 9, 2629, HZ, Delft, the Netherlands
| |
Collapse
|
16
|
Cooper R, Tsimring L, Hasty J. Microfluidics-Based Analysis of Contact-dependent Bacterial Interactions. Bio Protoc 2018; 8:e2970. [PMID: 30370317 PMCID: PMC6200413 DOI: 10.21769/bioprotoc.2970] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 07/28/2018] [Accepted: 08/06/2018] [Indexed: 11/02/2022] Open
Abstract
Bacteria in nature live in complex communities with multiple cell types and spatially-dependent interactions. Studying cells in well-mixed environments such as shaking culture tubes or flasks cannot capture these spatial dynamics, but cells growing in full-fledged biofilms are difficult to observe in real time. We present here a protocol for observing time-resolved, multi-species interactions at single-cell resolution. The protocol involves growing bacterial cells in a near monolayer in a microfluidic device. As a demonstration, we describe in particular observing the dynamic interactions between E. coli and Acinetobacter baylyi. In this case, the protocol is capable of observing both contact-dependent lysis of E. coli by A. baylyi via the Type VI Secretion System (T6SS) and subsequent functional horizontal gene transfer (HGT) of genes from E. coli to A. baylyi.
Collapse
Affiliation(s)
- Robert Cooper
- BioCircuits Institute, University of California, San Diego, La Jolla, CA, United States
| | - Lev Tsimring
- BioCircuits Institute, University of California, San Diego, La Jolla, CA, United States
- San Diego Center For Systems Biology, University of California, San Diego, La Jolla, CA, United States
| | - Jeff Hasty
- BioCircuits Institute, University of California, San Diego, La Jolla, CA, United States
- San Diego Center For Systems Biology, University of California, San Diego, La Jolla, CA, United States
- Division of Biological Science, University of California, Molecular Biology Section, La Jolla, CA, United States
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, United States
| |
Collapse
|
17
|
Javedani Bafekr J, Jalal R. In vitro antibacterial activity of ceftazidime, unlike ciprofloxacin, improves in the presence of ZnO nanofluids under acidic conditions. IET Nanobiotechnol 2018; 12:640-646. [PMID: 30095426 DOI: 10.1049/iet-nbt.2017.0119] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The development of antibiotic resistance among hospital pathogens has provided a great need for new antimicrobial agents. Zinc oxide nanoparticles (ZnO NPs) in combination with various antibiotics can act as a reducing agent for antibiotic resistance. The aim of this study was to investigate the influence and the mechanism of ZnO NPs on the antimicrobial activity of ciprofloxacin (CP) and ceftazidime (CAZ) against Enterococcus faecalis (E. faecalis) and Acinetobacter baumannii (A. baumannii) bacteria in acidic conditions (pH 5.5). ZnO NPs were synthesised using the solvothermal method and characterised. The MIC90 value of ZnO NPs against A. baumannii was 0.25 mg ml-1 and its highest growth-inhibitory activity was observed at 0.125 mg ml-1 for E. faecalis. The Fourier transform infrared spectroscopy spectra of ZnO NPs treated with antibiotics showed the interaction between ZnO NPs and each of the two antibiotics. ZnO NPs at a sub-inhibitory concentration had no effect on the antibacterial activity of CP and CAZ against E. faecalis and CP against A. baumannii. The action mechanism of ZnO NPs for enhancing the antibacterial efficacy of CAZ against A. baumannii was evaluated. ZnO NPs caused to increase in the antibacterial activity of CAZ against A. baumannii, possibly through the release of Zn2+ and increasing of membrane permeability.
Collapse
Affiliation(s)
- Jalil Javedani Bafekr
- Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Razieh Jalal
- Cell and Molecular Biotechnology Research Group, Institute of Biotechnology, Ferdowsi University of Mashhad, Mashhad, Iran.
| |
Collapse
|
18
|
Geisinger E, Mortman NJ, Vargas-Cuebas G, Tai AK, Isberg RR. A global regulatory system links virulence and antibiotic resistance to envelope homeostasis in Acinetobacter baumannii. PLoS Pathog 2018; 14:e1007030. [PMID: 29795704 PMCID: PMC5967708 DOI: 10.1371/journal.ppat.1007030] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 04/16/2018] [Indexed: 11/19/2022] Open
Abstract
The nosocomial pathogen Acinetobacter baumannii is a significant threat due to its ability to cause infections refractory to a broad range of antibiotic treatments. We show here that a highly conserved sensory-transduction system, BfmRS, mediates the coordinate development of both enhanced virulence and resistance in this microorganism. Hyperactive alleles of BfmRS conferred increased protection from serum complement killing and allowed lethal systemic disease in mice. BfmRS also augmented resistance and tolerance against an expansive set of antibiotics, including dramatic protection from β-lactam toxicity. Through transcriptome profiling, we showed that BfmRS governs these phenotypes through global transcriptional regulation of a post-exponential-phase-like program of gene expression, a key feature of which is modulation of envelope biogenesis and defense pathways. BfmRS activity defended against cell-wall lesions through both β-lactamase-dependent and -independent mechanisms, with the latter being connected to control of lytic transglycosylase production and proper coordination of morphogenesis and division. In addition, hypersensitivity of bfmRS knockouts could be suppressed by unlinked mutations restoring a short, rod cell morphology, indicating that regulation of drug resistance, pathogenicity, and envelope morphogenesis are intimately linked by this central regulatory system in A. baumannii. This work demonstrates that BfmRS controls a global regulatory network coupling cellular physiology to the ability to cause invasive, drug-resistant infections. Infections with the hospital-acquired bacterium Acinetobacter baumannii are highly difficult to treat. The pathogen has evolved multiple lines of defense against antimicrobial stress, including a barrier-forming cell envelope as well as control systems that respond to antimicrobial stresses by enhancing antibiotic resistance and virulence. Here, we uncovered the role of a key stress-response system, BfmRS, in controlling the transition of A. baumannii to a state of heightened resistance and virulence. We show that BfmRS enhances pathogenicity in mammalian hosts, and augments the ability to grow in the presence of diverse antibiotics and tolerate transient, high-level antibiotic exposures. Connected to these effects is the ability of BfmRS to globally reprogram gene expression and control multiple pathways that build, protect, and shape the cell envelope. Moreover, we determined that resistance-enhancing mutations bypassing the need for BfmRS also modulate envelope- and morphology-associated pathways, further linking control of physiology with resistance in A. baumannii. This work uncovers a global control circuit that shifts cellular physiology in ways that promote hospital-associated disease, and points to inhibition of this circuit as a potential strategy for disarming the pathogen.
Collapse
Affiliation(s)
- Edward Geisinger
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
- Howard Hughes Medical Institute, Boston, Massachusetts, United States of America
| | - Nadav J. Mortman
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Germán Vargas-Cuebas
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Albert K. Tai
- Department of Integrative Physiology and Pathobiology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Ralph R. Isberg
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
- Howard Hughes Medical Institute, Boston, Massachusetts, United States of America
- * E-mail:
| |
Collapse
|
19
|
Luo Y, Javed MA, Deneer H, Chen X. Nutrient depletion-induced production of tri-acylated glycerophospholipids in Acinetobacter radioresistens. Sci Rep 2018; 8:7470. [PMID: 29748546 PMCID: PMC5945596 DOI: 10.1038/s41598-018-25869-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 05/01/2018] [Indexed: 12/04/2022] Open
Abstract
Bacteria inhabit a vast range of biological niches and have evolved diverse mechanisms to cope with environmental stressors. The genus Acinetobacter comprises a complex group of Gram-negative bacteria. Some of these bacteria such as A. baumannii are nosocomial pathogens. They are often resistant to multiple antibiotics and are associated with epidemic outbreaks. A. radioresistens is generally considered to be a commensal bacterium on human skin or an opportunistic pathogen. Interestingly, this species has exceptional resistance to a range of environmental challenges which contributes to its persistence in clinical environment and on human skin. We studied changes in its lipid composition induced by the onset of stationary phase. This strain produced triglycerides (TG) as well as four common phospholipids: phosphatidylethanolamine (PE), phosphatidylglycerol (PG), cardiolipin (CL) and lysocardiolipin (LCL). It also produced small amounts of acyl-phosphatidylglycerol (APG). As the bacterial growth entered the stationary phase, the lipidome switched from one dominated by PE and PG to another dominated by CL and LCL. Surprisingly, bacteria in the stationary phase produced N-acyl-phosphatidylethanolamine (NAPE) and another rare lipid we tentatively name as 1-phosphatidyl-2-acyl-glycero-3-phosphoethanolamine (PAGPE) based on tandem mass spectrometry. It is possible these tri-acylated lipids play an important role in coping with nutrient depletion.
Collapse
Affiliation(s)
- Yu Luo
- Department of Biochemistry, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
| | - Muhammad Afzal Javed
- Department of Microbiology and Immunology, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Harry Deneer
- Department of Pathology and Laboratory Medicine, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.,Molecular Microbiology Laboratory, Division of Clinical Microbiology, Saskatoon Health Region, Saskatoon, Saskatchewan, Canada
| | - Xialu Chen
- Department of Biochemistry, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| |
Collapse
|
20
|
Cahill G, Walsh PK, Donnelly D. Improved Control of Brewery Yeast Pitching Using Image Analysis. JOURNAL OF THE AMERICAN SOCIETY OF BREWING CHEMISTS 2018. [DOI: 10.1094/asbcj-57-0072] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Gearoid Cahill
- Guinness Research and Development, St James's Gate, Dublin 8, Ireland
| | - Padraig K. Walsh
- School of Biotechnology, Dublin City University, Dublin 9, Ireland
| | | |
Collapse
|
21
|
A Single Regulator Mediates Strategic Switching between Attachment/Spread and Growth/Virulence in the Plant Pathogen Ralstonia solanacearum. mBio 2017; 8:mBio.00895-17. [PMID: 28951474 PMCID: PMC5615195 DOI: 10.1128/mbio.00895-17] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The PhcA virulence regulator in the vascular wilt pathogen Ralstonia solanacearum responds to cell density via quorum sensing. To understand the timing of traits that enable R. solanacearum to establish itself inside host plants, we created a ΔphcA mutant that is genetically locked in a low-cell-density condition. Comparing levels of gene expression of wild-type R. solanacearum and the ΔphcA mutant during tomato colonization revealed that the PhcA transcriptome includes an impressive 620 genes (>2-fold differentially expressed; false-discovery rate [FDR], ≤0.005). Many core metabolic pathways and nutrient transporters were upregulated in the ΔphcA mutant, which grew faster than the wild-type strain in tomato xylem sap and on dozens of specific metabolites, including 36 found in xylem. This suggests that PhcA helps R. solanacearum to survive in nutrient-poor environmental habitats and to grow rapidly during early pathogenesis. However, after R. solanacearum reaches high cell densities in planta, PhcA mediates a trade-off from maximizing growth to producing costly virulence factors. R. solanacearum infects through roots, and low-cell-density-mode-mimicking ΔphcA cells attached to tomato roots better than the wild-type cells, consistent with their increased expression of several adhesins. Inside xylem vessels, ΔphcA cells formed aberrantly dense mats. Possibly as a result, the mutant could not spread up or down tomato stems as well as the wild type. This suggests that aggregating improves R. solanacearum survival in soil and facilitates infection and that it reduces pathogenic fitness later in disease. Thus, PhcA mediates a second strategic switch between initial pathogen attachment and subsequent dispersal inside the host. PhcA helps R. solanacearum optimally invest resources and correctly sequence multiple steps in the bacterial wilt disease cycle. Ralstonia solanacearum is a destructive soilborne crop pathogen that wilts plants by colonizing their water-transporting xylem vessels. It produces its costly virulence factors only after it has grown to a high population density inside a host. To identify traits that this pathogen needs in other life stages, we studied a mutant that mimics the low-cell-density condition. This mutant (the ΔphcA mutant) cannot sense its own population density. It grew faster than and used many nutrients not available to the wild-type bacterium, including metabolites present in tomato xylem sap. The mutant also attached much better to tomato roots, and yet it failed to spread once it was inside plants because it was trapped in dense mats. Thus, PhcA helps R. solanacearum succeed over the course of its complex life cycle by ensuring avid attachment to plant surfaces and rapid growth early in disease, followed by high virulence and effective dispersal later in disease.
Collapse
|
22
|
Todhanakasem T. Developing microbial biofilm as a robust biocatalyst and its challenges. BIOCATAL BIOTRANSFOR 2017. [DOI: 10.1080/10242422.2017.1295230] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Tatsaporn Todhanakasem
- Department of Agro-Industry, Faculty of Biotechnology, Assumption University, Bangkok, Thailand
| |
Collapse
|
23
|
Oyehan TA, Al-Thukair AA. Isolation and characterization of PAH-degrading bacteria from the Eastern Province, Saudi Arabia. MARINE POLLUTION BULLETIN 2017; 115:39-46. [PMID: 27912917 DOI: 10.1016/j.marpolbul.2016.11.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 10/25/2016] [Accepted: 11/06/2016] [Indexed: 06/06/2023]
Abstract
Contaminated sediment samples were collected from the Eastern Province, Saudi Arabia for isolation of pyrene- and phenanthrene-degrading bacteria by enrichment method. Four isolates were morphologically characterized as Gram-negative rod strains and 16S rRNA sequence analysis revealed the isolates as closely related to Pseudomonas aeruginosa, P. citronellolis, Ochrobactrum intermedium and Cupriavidus taiwanensis. Degradation of the polycyclic aromatic hydrocarbons (PAHs) by the latter three strains was investigated in liquid cultures. Results of concentration reduction analyzed with gas chromatography show that P. citronellolis_LB was efficient in removing phenanthrene, degrading 94% of 100ppm in 15days while O. intermedium_BC1 was more efficient in pyrene-removal, degrading 62% in 2weeks. Furthermore, bacterial growth assessment using optical density and population counts revealed the latter as more suitable for microbial growth analysis in PAH-containing cultures. In conclusion, the isolated bacterial strains could be further developed for efficient use in biodegradation of PAH.
Collapse
Affiliation(s)
- Tajudeen A Oyehan
- Environmental Sciences Program of Earth Sciences Dept., King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia
| | - Assad A Al-Thukair
- Life Sciences Dept., King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia.
| |
Collapse
|
24
|
Díaz De Rienzo MA, Stevenson PS, Marchant R, Banat IM. Pseudomonas aeruginosa biofilm disruption using microbial surfactants. J Appl Microbiol 2016; 120:868-76. [PMID: 26742560 DOI: 10.1111/jam.13049] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 12/23/2015] [Accepted: 01/04/2016] [Indexed: 11/26/2022]
Abstract
AIMS To establish the ability of the rhamnolipids biosurfactants from Pseudomonas aeruginosa, in the presence and absence of caprylic acid and ascorbic acid, to disrupt bacterial biofilms, compared with the anionic alkyl sulphate surfactant Sodium dodecyl sulphate (SDS). METHODS AND RESULTS Pseudomonas aeruginosa ATCC 15442 biofilms were disrupted by rhamnolipids at concentrations between 0·5 and 0·4 g l(-1) and with SDS at 0·8 g l(-1) . The combination of rhamnolipids 0·4 g l(-1) and caprylic acid at 0·1 g l(-1) showed a remarkable effect on biofilm disruption and cell killing. After 30 min of treatment most of the biofilm was disrupted and cell viability was significantly reduced. Neither caprylic acid nor ascorbic acid has any effect on biofilm disruption at 0·1 g l(-1) . SDS is an effective antimicrobial agent; however, in the presence of caprylic acid its effect was neutralized. CONCLUSIONS The results show that rhamnolipids at low concentration in the presence of caprylic acid are promising molecules for inhibition/disruption of biofilms formed by Ps. aeruginosa ATCC 15442. SIGNIFICANCE AND IMPACT OF THE STUDY The disruption of biofilms has major significance in many industrial and domestic cleaning applications and in medical situations.
Collapse
Affiliation(s)
- M A Díaz De Rienzo
- School of Chemical Engineering and Analytical Science, University of Manchester, Manchester, UK
| | - P S Stevenson
- Unilever Research and Development Laboratory, Port Sunlight, Wirral, UK
| | - R Marchant
- School of Biomedical Sciences, University of Ulster, Coleraine, UK
| | - I M Banat
- School of Biomedical Sciences, University of Ulster, Coleraine, UK
| |
Collapse
|
25
|
Affiliation(s)
- Priya Uppuluri
- The Division of Infectious Diseases, Los Angeles Biomedical Research Institute at Harbor-University of California Los Angeles (UCLA) Medical Center, Los Angeles, California, United States of America
- * E-mail:
| | - Jose L. Lopez-Ribot
- Department of Biology and South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, Texas, United States of America
| |
Collapse
|
26
|
Petrova OE, Sauer K. Escaping the biofilm in more than one way: desorption, detachment or dispersion. Curr Opin Microbiol 2016; 30:67-78. [PMID: 26826978 DOI: 10.1016/j.mib.2016.01.004] [Citation(s) in RCA: 151] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Revised: 01/07/2016] [Accepted: 01/08/2016] [Indexed: 12/15/2022]
Abstract
Biofilm bacteria have developed escape strategies to avoid stresses associated with biofilm growth, respond to changing environmental conditions, and disseminate to new locations. An ever-expanding body of research suggests that cellular release from biofilms is distinct from a simple reversal of attachment and reversion to a planktonic mode of growth, with biofilm dispersion involving sensing of specific cues, regulatory signal transduction, and consequent physiological alterations. However, dispersion is only one of many ways to escape the biofilm mode of growth. The present review is aimed at distinguishing this active and regulated process of dispersion from the passive processes of desorption and detachment by highlighting the regulatory processes and distinct phenotypes specific to dispersed cells.
Collapse
Affiliation(s)
- Olga E Petrova
- Department of Biological Sciences, Binghamton Biofilm Research Center, Binghamton University, Binghamton, NY 13902, United States
| | - Karin Sauer
- Department of Biological Sciences, Binghamton Biofilm Research Center, Binghamton University, Binghamton, NY 13902, United States.
| |
Collapse
|
27
|
Winters YD, Lowenstein TK, Timofeeff MN. Starvation-Survival in Haloarchaea. Life (Basel) 2015; 5:1587-609. [PMID: 26569313 PMCID: PMC4695838 DOI: 10.3390/life5041587] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 10/09/2015] [Accepted: 10/23/2015] [Indexed: 11/16/2022] Open
Abstract
Recent studies claiming to revive ancient microorganisms trapped in fluid inclusions in halite have warranted an investigation of long-term microbial persistence. While starvation-survival is widely reported for bacteria, it is less well known for halophilic archaea-microorganisms likely to be trapped in ancient salt crystals. To better understand microbial survival in fluid inclusions in ancient evaporites, laboratory experiments were designed to simulate growth of halophilic archaea under media-rich conditions, complete nutrient deprivation, and a controlled substrate condition (glycerol-rich) and record their responses. Haloarchaea used for this work included Hbt. salinarum and isolate DV582A-1 (genus Haloterrigena) sub-cultured from 34 kyear Death Valley salt. Hbt. salinarum and DV582A-1 reacted to nutrient limitation with morphological and population changes. Starved populations increased and most cells converted from rods to small cocci within 56 days of nutrient deprivation. The exact timing of starvation adaptations and the physical transformations differed between species, populations of the same species, and cells of the same population. This is the first study to report the timing of starvation strategies for Hbt. salinarum and DV582A-1. The morphological states in these experiments may allow differentiation between cells trapped with adequate nutrients (represented here by early stages in nutrient-rich media) from cells trapped without nutrients (represented here by experimental starvation) in ancient salt. The hypothesis that glycerol, leaked from Dunaliella, provides nutrients for the survival of haloarchaea trapped in fluid inclusions in ancient halite, is also tested. Hbt. salinarum and DV582A-1 were exposed to a mixture of lysed and intact Dunaliella for 56 days. The ability of these organisms to utilize glycerol from Dunaliella cells was assessed by documenting population growth, cell length, and cell morphology. Hbt. salinarum and DV582A-1 experienced size reductions and shape transitions from rods to cocci. In the short-term, these trends more closely resembled the response of these organisms to starvation conditions than to nutrient-rich media. Results from this experiment reproduced the physical state of cells (small cocci) in ancient halite where prokaryotes co-exist with single-celled algae. We conclude that glycerol is not the limiting factor in the survival of haloarchaea for thousands of years in fluid inclusions in halite.
Collapse
|
28
|
Phippen BL, Oliver JD. Clinical and environmental genotypes of Vibrio vulnificus display distinct, quorum-sensing-mediated, chitin detachment dynamics. Pathog Dis 2015; 73:ftv072. [PMID: 26377182 DOI: 10.1093/femspd/ftv072] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/13/2015] [Indexed: 12/15/2022] Open
Abstract
The ability for bacteria to attach to and detach from various substrata is important for colonization, survival and transitioning to new environments. An opportunistic human pathogen, Vibrio vulnificus, can cause potentially fatal septicemia after ingestion of undercooked seafood. Based on genetic polymorphisms, strains of this species are subtyped into clinical (C) and environmental (E) genotypes. Vibrio vulnificus readily associates with chitin, thus we investigated chitin detachment dynamics in these disparate genotypes. We found that C-genotypes detach significantly more than E-genotypes after 24 hours in aerobic as well as anaerobic conditions. Furthermore, expression of genes involved in type IV pilin production was significantly downregulated in C-genotypes compared to E-genotypes, suggesting an importance in detachment. Interestingly, gbpA, a gene that has been shown to be important in host colonization in V. cholerae, was upregulated in the C-genotypes during detachment. Additionally, we found that C-genotypes detached to a greater extent, and produced more quorum-sensing (QS) autoinducer-2 molecules relative to E-genotypes, which suggests a role for QS in detachment. These findings suggest that for V. vulnificus, QS-mediated detachment may be a potential mechanism for transitioning into a human host for C-genotypes, while facilitating E-genotype maintenance in the estuarine environment.
Collapse
Affiliation(s)
- Britney L Phippen
- Biological Sciences, UNCC, 9201 University City Blvd, Charlotte, NC 28223, USA
| | - James D Oliver
- Department of Biological Sciences, The University of North Carolina at Charlotte, Charlotte, NC 28223, USA
| |
Collapse
|
29
|
Akbari F, Kjellerup BV. Elimination of Bloodstream Infections Associated with Candida albicans Biofilm in Intravascular Catheters. Pathogens 2015; 4:457-69. [PMID: 26131615 PMCID: PMC4584267 DOI: 10.3390/pathogens4030457] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Revised: 06/07/2015] [Accepted: 06/19/2015] [Indexed: 11/16/2022] Open
Abstract
Intravascular catheters are among the most commonly inserted medical devices and they are known to cause a large number of catheter related bloodstream infections (BSIs). Biofilms are associated with many chronic infections due to the aggregation of microorganisms. One of these organisms is the fungus Candida albicans. It has shown to be one of the leading causes of catheter-related BSIs. The presence of biofilm on intravascular catheters provide increased tolerance against antimicrobial treatments, thus alternative treatment strategies are sought. Traditionally, many strategies, such as application of combined antimicrobials, addition of antifungals, and removal of catheters, have been practiced, but they were not successful in eradicating BSIs. Since these fungal infections can result in significant morbidity, mortality, and increased healthcare cost, other promising preventive strategies, including antimicrobial lock therapy, chelating agents, alcohol, and biofilm disruptors, have been applied. In this review, current success and failure of these new approaches, and a comparison with the previous strategies are discussed in order to understand which preventative treatment is the most effective in controlling the catheter-related BSIs.
Collapse
Affiliation(s)
- Freshta Akbari
- Department of Biological Sciences, Goucher College, Baltimore, MD 21204, USA.
| | - Birthe Veno Kjellerup
- Department of Civil and Environmental Engineering, University of Maryland at College Park, College Park, MD 20742, USA.
| |
Collapse
|
30
|
Development of Spatial Distribution Patterns by Biofilm Cells. Appl Environ Microbiol 2015; 81:6120-8. [PMID: 26116674 DOI: 10.1128/aem.01614-15] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Accepted: 06/19/2015] [Indexed: 01/14/2023] Open
Abstract
Confined spatial patterns of microbial distribution are prevalent in nature, such as in microbial mats, soil communities, and water stream biofilms. The symbiotic two-species consortium of Pseudomonas putida and Acinetobacter sp. strain C6, originally isolated from a creosote-polluted aquifer, has evolved a distinct spatial organization in the laboratory that is characterized by an increased fitness and productivity. In this consortium, P. putida is reliant on microcolonies formed by Acinetobacter sp. C6, to which it attaches. Here we describe the processes that lead to the microcolony pattern by Acinetobacter sp. C6. Ecological spatial pattern analyses revealed that the microcolonies were not entirely randomly distributed and instead were arranged in a uniform pattern. Detailed time-lapse confocal microscopy at the single-cell level demonstrated that the spatial pattern was the result of an intriguing self-organization: small multicellular clusters moved along the surface to fuse with one another to form microcolonies. This active distribution capability was dependent on environmental factors (carbon source and oxygen) and historical contingency (formation of phenotypic variants). The findings of this study are discussed in the context of species distribution patterns observed in macroecology, and we summarize observations about the processes involved in coadaptation between P. putida and Acinetobacter sp. C6. Our results contribute to an understanding of spatial species distribution patterns as they are observed in nature, as well as the ecology of engineered communities that have the potential for enhanced and sustainable bioprocessing capacity.
Collapse
|
31
|
Juma NA, Forsythe SJ. Microbial Biofilm Development on Neonatal Enteral Feeding Tubes. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 830:113-21. [DOI: 10.1007/978-3-319-11038-7_7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
|
32
|
The diguanylate cyclase GcbA facilitates Pseudomonas aeruginosa biofilm dispersion by activating BdlA. J Bacteriol 2014; 197:174-87. [PMID: 25331436 DOI: 10.1128/jb.02244-14] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Biofilm dispersion is a highly regulated process that allows biofilm bacteria to respond to changing environmental conditions and to disseminate to new locations. The dispersion of biofilms formed by the opportunistic pathogen Pseudomonas aeruginosa is known to require a number of cyclic di-GMP (c-di-GMP)-degrading phosphodiesterases (PDEs) and the chemosensory protein BdlA, with BdlA playing a pivotal role in regulating PDE activity and enabling dispersion in response to a wide array of cues. BdlA is activated during biofilm growth via posttranslational modifications and nonprocessive cleavage in a manner that is dependent on elevated c-di-GMP levels. Here, we provide evidence that the diguanylate cyclase (DGC) GcbA contributes to the regulation of BdlA cleavage shortly after initial cellular attachment to surfaces and, thus, plays an essential role in allowing biofilm cells to disperse in response to increasing concentrations of a variety of substances, including carbohydrates, heavy metals, and nitric oxide. DGC activity of GcbA was required for its function, as a catalytically inactive variant could not rescue impaired BdlA processing or the dispersion-deficient phenotype of gcbA mutant biofilms to wild-type levels. While modulating BdlA cleavage during biofilm growth, GcbA itself was found to be subject to c-di-GMP-dependent and growth-mode-specific regulation. GcbA production was suppressed in mature wild-type biofilms and could be induced by reducing c-di-GMP levels via overexpression of genes encoding PDEs. Taken together, the present findings demonstrate that the regulatory functions of c-di-GMP-synthesizing DGCs expand beyond surface attachment and biofilm formation and illustrate a novel role for DGCs in the regulation of the reverse sessile-motile transition of dispersion.
Collapse
|
33
|
Siegismund D, Schroeter A, Lüdecke C, Undisz A, Jandt KD, Roth M, Rettenmayr M, Schuster S, Germerodt S. Discrimination between random and non-random processes in early bacterial colonization on biomaterial surfaces: application of point pattern analysis. BIOFOULING 2014; 30:1023-1033. [PMID: 25329612 DOI: 10.1080/08927014.2014.958999] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The dynamics of adhesion and growth of bacterial cells on biomaterial surfaces play an important role in the formation of biofilms. The surface properties of biomaterials have a major impact on cell adhesion processes, eg the random/non-cooperative adhesion of bacteria. In the present study, the spatial arrangement of Escherichia coli on different biomaterials is investigated in a time series during the first hours after exposure. The micrographs are analyzed via an image processing routine and the resulting point patterns are evaluated using second order statistics. Two main adhesion mechanisms can be identified: random adhesion and non-random processes. Comparison with an appropriate null-model quantifies the transition between the two processes with statistical significance. The fastest transition to non-random processes was found to occur after adhesion on PTFE for 2-3 h. Additionally, determination of cell and cluster parameters via image processing gives insight into surface influenced differences in bacterial micro-colony formation.
Collapse
Affiliation(s)
- Daniel Siegismund
- a Otto Schott Institute of Materials Research (OSIM) , Friedrich Schiller University Jena , Jena , Germany
| | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Responses of unsaturated Pseudomonas putida CZ1 biofilms to environmental stresses in relation to the EPS composition and surface morphology. World J Microbiol Biotechnol 2014; 30:3081-90. [DOI: 10.1007/s11274-014-1735-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 08/31/2014] [Indexed: 10/24/2022]
|
35
|
Cavaliere R, Ball JL, Turnbull L, Whitchurch CB. The biofilm matrix destabilizers, EDTA and DNaseI, enhance the susceptibility of nontypeable Hemophilus influenzae biofilms to treatment with ampicillin and ciprofloxacin. Microbiologyopen 2014; 3:557-67. [PMID: 25044339 PMCID: PMC4287182 DOI: 10.1002/mbo3.187] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2014] [Revised: 05/09/2014] [Accepted: 05/28/2014] [Indexed: 12/30/2022] Open
Abstract
Nontypeable Hemophilus influenzae (NTHi) is a Gram-negative bacterial pathogen that causes chronic biofilm infections of the ears and airways. The biofilm matrix provides structural integrity to the biofilm and protects biofilm cells from antibiotic exposure by reducing penetration of antimicrobial compounds into the biofilm. Extracellular DNA (eDNA) has been found to be a major matrix component of biofilms formed by many species of Gram-positive and Gram-negative bacteria, including NTHi. Interestingly, the cation chelator ethylenediaminetetra-acetic acid (EDTA) has been shown to reduce the matrix strength of biofilms of several bacterial species as well as to have bactericidal activity against various pathogens. EDTA exerts its antimicrobial activity by chelating divalent cations necessary for growth and membrane stability and by destabilizing the matrix thus enhancing the detachment of bacterial cells from the biofilm. In this study, we have explored the role of divalent cations in NTHi biofilm development and stability. We have utilized in vitro static and continuous flow models of biofilm development by NTHi to demonstrate that magnesium cations enhance biofilm formation by NTHi. We found that the divalent cation chelator EDTA is effective at both preventing NTHi biofilm formation and at treating established NTHi biofilms. Furthermore, we found that the matrix destablilizers EDTA and DNaseI increase the susceptibility of NTHi biofilms to ampicillin and ciprofloxacin. Our observations indicate that DNaseI and EDTA enhance the efficacy of antibiotic treatment of NTHi biofilms. These observations may lead to new strategies that will improve the treatment options available to patients with chronic NTHi infections.
Collapse
Affiliation(s)
- Rosalia Cavaliere
- The ithree Institute, University of Technology Sydney, Sydney, New South Wales, Australia
| | | | | | | |
Collapse
|
36
|
Park JH, Lee JK, Um HS, Chang BS, Lee SY. A periodontitis-associated multispecies model of an oral biofilm. J Periodontal Implant Sci 2014; 44:79-84. [PMID: 24778902 PMCID: PMC3999356 DOI: 10.5051/jpis.2014.44.2.79] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Accepted: 03/20/2014] [Indexed: 12/03/2022] Open
Affiliation(s)
- Jong Hwa Park
- Department of Periodontology, Research Institute of Oral Sciences, Gangneung-Wonju National University College of Dentistry, Gangneung, Korea
| | - Jae-Kwan Lee
- Department of Periodontology, Research Institute of Oral Sciences, Gangneung-Wonju National University College of Dentistry, Gangneung, Korea
| | - Heung-Sik Um
- Department of Periodontology, Research Institute of Oral Sciences, Gangneung-Wonju National University College of Dentistry, Gangneung, Korea
| | - Beom-Seok Chang
- Department of Periodontology, Research Institute of Oral Sciences, Gangneung-Wonju National University College of Dentistry, Gangneung, Korea
| | - Si-Young Lee
- Department of Microbiology and Immunology, Research Institute of Oral Sciences, Gangneung-Wonju National University College of Dentistry, Gangneung, Korea
| |
Collapse
|
37
|
Penterman J, Nguyen D, Anderson E, Staudinger BJ, Greenberg EP, Lam JS, Singh PK. Rapid evolution of culture-impaired bacteria during adaptation to biofilm growth. Cell Rep 2014; 6:293-300. [PMID: 24412364 DOI: 10.1016/j.celrep.2013.12.019] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Revised: 10/17/2013] [Accepted: 12/12/2013] [Indexed: 11/17/2022] Open
Abstract
Biofilm growth increases the fitness of bacteria in harsh conditions. However, bacteria from clinical and environmental biofilms can exhibit impaired growth in culture, even when the species involved are readily culturable and permissive conditions are used. Here, we show that culture-impaired variants of Pseudomonas aeruginosa arise rapidly and become abundant in laboratory biofilms. The culture-impaired phenotype is caused by mutations that alter the outer-membrane lipopolysaccharide structure. Within biofilms, the lipopolysaccharide mutations markedly increase bacterial fitness. However, outside the protected biofilm environment, the mutations sensitize the variants to killing by a self-produced antimicrobial agent. Thus, a biofilm-mediated adaptation produces a stark fitness trade-off that compromises bacterial survival in culture. Trade-offs like this could limit the ability of bacteria to transition between biofilm growth and the free-living state and produce bacterial populations that escape detection by culture-based sampling.
Collapse
Affiliation(s)
- Jon Penterman
- Departments of Medicine and Microbiology, University of Washington School of Medicine, Seattle, WA 98195, USA.
| | - Dao Nguyen
- Department of Medicine, McGill University, Montreal, QC H3G 1A4, Canada
| | - Erin Anderson
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Benjamin J Staudinger
- Department of Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Everett P Greenberg
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Joseph S Lam
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Pradeep K Singh
- Departments of Medicine and Microbiology, University of Washington School of Medicine, Seattle, WA 98195, USA
| |
Collapse
|
38
|
Perez LRR. Acinetobacter baumannii displays inverse relationship between meropenem resistance and biofilm production. J Chemother 2014; 27:13-6. [PMID: 24621167 DOI: 10.1179/1973947813y.0000000159] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
In this study the ability for biofilm production among meropenem (MEM)-resistant and -susceptible Acinetobacter baumannii isolates was verified. MEM susceptibility and biofilm production were screened in 116 isolates. Meropenem-resistant A. baumannii isolates showed a reduced ability to produce biofilms compared to those susceptible to MEM (P<0.0001). The results suggest an inverse relationship between biofilm production and MEM resistance in nosocomial A. baumanni isolates.
Collapse
|
39
|
Ecological roles and biotechnological applications of marine and intertidal microbial biofilms. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2014; 146:163-205. [PMID: 24817086 DOI: 10.1007/10_2014_271] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
This review is a retrospective of ecological effects of bioactivities produced by biofilms of surface-dwelling marine/intertidal microbes as well as of the industrial and environmental biotechnologies developed exploiting the knowledge of biofilm formation. Some examples of significant interest pertaining to the ecological aspects of biofilm-forming species belonging to the Roseobacter clade include autochthonous bacteria from turbot larvae-rearing units with potential application as a probiotic as well as production of tropodithietic acid and indigoidine. Species of the Pseudoalteromonas genus are important examples of successful surface colonizers through elaboration of the AlpP protein and antimicrobial agents possessing broad-spectrum antagonistic activity against medical and environmental isolates. Further examples of significance comprise antiprotozoan activity of Pseudoalteromonas tunicata elicited by violacein, inhibition of fungal colonization, antifouling activities, inhibition of algal spore germination, and 2-n-pentyl-4-quinolinol production. Nitrous oxide, an important greenhouse gas, emanates from surface-attached microbial activity of marine animals. Marine and intertidal biofilms have been applied in the biotechnological production of violacein, phenylnannolones, and exopolysaccharides from marine and tropical intertidal environments. More examples of importance encompass production of protease, cellulase, and xylanase, melanin, and riboflavin. Antifouling activity of Bacillus sp. and application of anammox bacterial biofilms in bioremediation are described. Marine biofilms have been used as anodes and cathodes in microbial fuel cells. Some of the reaction vessels for biofilm cultivation reviewed are roller bottle, rotating disc bioreactor, polymethylmethacrylate conico-cylindrical flask, fixed bed reactor, artificial microbial mats, packed-bed bioreactors, and the Tanaka photobioreactor.
Collapse
|
40
|
|
41
|
Noise-free accurate count of microbial colonies by time-lapse shadow image analysis. J Microbiol Methods 2012; 91:420-8. [PMID: 23085533 DOI: 10.1016/j.mimet.2012.09.028] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2012] [Revised: 09/21/2012] [Accepted: 09/21/2012] [Indexed: 11/22/2022]
Abstract
Microbial colonies in food matrices could be counted accurately by a novel noise-free method based on time-lapse shadow image analysis. An agar plate containing many clusters of microbial colonies and/or meat fragments was trans-illuminated to project their 2-dimensional (2D) shadow images on a color CCD camera. The 2D shadow images of every cluster distributed within a 3-mm thick agar layer were captured in focus simultaneously by means of a multiple focusing system, and were then converted to 3-dimensional (3D) shadow images. By time-lapse analysis of the 3D shadow images, it was determined whether each cluster comprised single or multiple colonies or a meat fragment. The analytical precision was high enough to be able to distinguish a microbial colony from a meat fragment, to recognize an oval image as two colonies contacting each other, and to detect microbial colonies hidden under a food fragment. The detection of hidden colonies is its outstanding performance in comparison with other systems. The present system attained accuracy for counting fewer than 5 colonies and is therefore of practical importance.
Collapse
|
42
|
Kalia D, Merey G, Nakayama S, Zheng Y, Zhou J, Luo Y, Guo M, Roembke BT, Sintim HO. Nucleotide, c-di-GMP, c-di-AMP, cGMP, cAMP, (p)ppGpp signaling in bacteria and implications in pathogenesis. Chem Soc Rev 2012; 42:305-41. [PMID: 23023210 DOI: 10.1039/c2cs35206k] [Citation(s) in RCA: 261] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
For an organism to survive, it must be able to sense its environment and regulate physiological processes accordingly. Understanding how bacteria integrate signals from various environmental factors and quorum sensing autoinducers to regulate the metabolism of various nucleotide second messengers c-di-GMP, c-di-AMP, cGMP, cAMP and ppGpp, which control several key processes required for adaptation is key for efforts to develop agents to curb bacterial infections. In this review, we provide an update of nucleotide signaling in bacteria and show how these signals intersect or integrate to regulate the bacterial phenotype. The intracellular concentrations of nucleotide second messengers in bacteria are regulated by synthases and phosphodiesterases and a significant number of these metabolism enzymes had been biochemically characterized but it is only in the last few years that the effector proteins and RNA riboswitches, which regulate bacterial physiology upon binding to nucleotides, have been identified and characterized by biochemical and structural methods. C-di-GMP, in particular, has attracted immense interest because it is found in many bacteria and regulate both biofilm formation and virulence factors production. In this review, we discuss how the activities of various c-di-GMP effector proteins and riboswitches are modulated upon c-di-GMP binding. Using V. cholerae, E. coli and B. subtilis as models, we discuss how both environmental factors and quorum sensing autoinducers regulate the metabolism and/or processing of nucleotide second messengers. The chemical syntheses of the various nucleotide second messengers and the use of analogs thereof as antibiofilm or immune modulators are also discussed.
Collapse
Affiliation(s)
- Dimpy Kalia
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
43
|
Dispersion by Pseudomonas aeruginosa requires an unusual posttranslational modification of BdlA. Proc Natl Acad Sci U S A 2012; 109:16690-5. [PMID: 23012421 DOI: 10.1073/pnas.1207832109] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Dispersion enables biofilm bacteria to transit from the biofilm to the planktonic growth state and to spawn novel communities in new locales. Although the chemotaxis protein BdlA plays a role in the dispersion of Pseudomonas aeruginosa biofilms in response to environmental cues, little is known about regulation of BdlA activity or how BdlA modulates the dispersion response. Here, we demonstrate that BdlA in its native form is inactive and is activated upon nonprocessive proteolysis at a ClpP-protease-like cleavage site located between the Per Arnt Sim (PAS) sensory domains PASa and PASb. Activation of BdlA to enable biofilm dispersion requires phosphorylation at tyrosine-238 as a signal, elevated c-di-GMP levels, the chaperone ClpD, and the protease ClpP. The resulting truncated BdlA polypeptide chains directly interact and are required for P. aeruginosa biofilms to disperse. Our results provide a basis for understanding the mechanism of biofilm dispersion that may be applicable to a large number of biofilm-forming pathogenic species. Insights into the mechanism of BdlA function have implications for the control of biofilm-related infections.
Collapse
|
44
|
PAS domain residues and prosthetic group involved in BdlA-dependent dispersion response by Pseudomonas aeruginosa biofilms. J Bacteriol 2012; 194:5817-28. [PMID: 22923587 DOI: 10.1128/jb.00780-12] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Biofilm dispersion by Pseudomonas aeruginosa in response to environmental cues is dependent on the cytoplasmic BdlA protein harboring two sensory PAS domains and a chemoreceptor domain, TarH. The closest known and previously characterized BdlA homolog is the flavin adenine dinucleotide (FAD)-binding Aer, the redox potential sensor and aerotaxis transducer in Escherichia coli. Here, we made use of alanine replacement mutagenesis of the BdlA PAS domain residues previously demonstrated to be essential for aerotaxis in Aer to determine whether BdlA is a potential sensory protein. Five substitutions (D14A, N23A, W60A, I109A, and W182A) resulted in a null phenotype for dispersion. One protein, the BdlA protein with the G31A mutation (BdlA-G31A), transmitted a constant signal-on bias as it rendered P. aeruginosa biofilms hyperdispersive. The hyperdispersive phenotype correlated with increased interaction of BdlA-G31A with the phosphodiesterase DipA under biofilm growth conditions, resulting in increased phosphodiesterase activity and reduced biofilm biomass accumulation. We furthermore demonstrate that BdlA is a heme-binding protein. None of the BdlA protein variants analyzed led to a loss of the heme prosthetic group. The N-terminal PASa domain was identified as the heme-binding domain of BdlA, with BdlA-dependent nutrient-induced dispersion requiring the PASa domain. The findings suggest that BdlA plays a role in intracellular sensing of dispersion-inducing conditions and together with DipA forms a regulatory network that modulates an intracellular cyclic d-GMP (c-di-GMP) pool to enable dispersion.
Collapse
|
45
|
Quilès F, Polyakov P, Humbert F, Francius G. Production of extracellular glycogen by Pseudomonas fluorescens: spectroscopic evidence and conformational analysis by biomolecular recognition. Biomacromolecules 2012; 13:2118-27. [PMID: 22686500 DOI: 10.1021/bm300497c] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Glycogen is mainly found as the principal storage form of glucose in cells. Many bacteria are able to synthesize large amounts of glycogen under unfavorable life conditions. By combining infrared spectroscopy, single molecule force spectroscopy (SMFS) and immuno-staining technique, we evidenced that planktonic P. fluorescens (Pf) cells are also able to produce glycogen as an extracellular polymeric substance. For this purpose, Pf suspensions were examined at 3 and 21 h of growth in nutritive medium (LB, 0.5 g/L). The conformation of the extracellular glycogen, revealed through its infrared spectral signature, has been investigated by SMFS measurements using Freely Jointed Chain model. The analysis of force versus distance curves showed over growth time that the increase of glycogen production was accompanied by an increase in glycogen contour lengths and ramifications. These results demonstrated that the production of extracellular bacterial glycogen can occur even if the cells are not subjected to unfavorable life conditions.
Collapse
Affiliation(s)
- Fabienne Quilès
- Université de Lorraine, Laboratoire de Chimie Physique et Microbiologie pour l'Environnement, LCPME, UMR 7564, Villers-lès-Nancy, France.
| | | | | | | |
Collapse
|
46
|
Carpenter BL, Feese E, Sadeghifar H, Argyropoulos DS, Ghiladi RA. Porphyrin-Cellulose Nanocrystals: A Photobactericidal Material that Exhibits Broad Spectrum Antimicrobial Activity†. Photochem Photobiol 2012; 88:527-36. [DOI: 10.1111/j.1751-1097.2012.01117.x] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
47
|
Hamanaka D, Onishi M, Genkawa T, Tanaka F, Uchino T. Effects of temperature and nutrient concentration on the structural characteristics and removal of vegetable-associated Pseudomonas biofilm. Food Control 2012. [DOI: 10.1016/j.foodcont.2011.09.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
48
|
Should we stay or should we go: mechanisms and ecological consequences for biofilm dispersal. Nat Rev Microbiol 2011; 10:39-50. [PMID: 22120588 DOI: 10.1038/nrmicro2695] [Citation(s) in RCA: 522] [Impact Index Per Article: 40.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
In most environments, bacteria reside primarily in biofilms, which are social consortia of cells that are embedded in an extracellular matrix and undergo developmental programmes resulting in a predictable biofilm 'life cycle'. Recent research on many different bacterial species has now shown that the final stage in this life cycle includes the production and release of differentiated dispersal cells. The formation of these cells and their eventual dispersal is initiated through diverse and remarkably sophisticated mechanisms, suggesting that there are strong evolutionary pressures for dispersal from an otherwise largely sessile biofilm. The evolutionary aspect of biofilm dispersal is now being explored through the integration of molecular microbiology with eukaryotic ecological and evolutionary theory, which provides a broad conceptual framework for the diversity of specific mechanisms underlying biofilm dispersal. Here, we review recent progress in this emerging field and suggest that the merging of detailed molecular mechanisms with ecological theory will significantly advance our understanding of biofilm biology and ecology.
Collapse
|
49
|
Surviving bacterial sibling rivalry: inducible and reversible phenotypic switching in Paenibacillus dendritiformis. mBio 2011; 2:e00069-11. [PMID: 21628502 PMCID: PMC3104493 DOI: 10.1128/mbio.00069-11] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Natural habitats vary in available nutrients and room for bacteria to grow, but successful colonization can lead to overcrowding and stress. Here we show that competing sibling colonies of Paenibacillus dendritiformis bacteria survive overcrowding by switching between two distinct vegetative phenotypes, motile rods and immotile cocci. Growing colonies of the rod-shaped bacteria produce a toxic protein, Slf, which kills cells of encroaching sibling colonies. However, sublethal concentrations of Slf induce some of the rods to switch to Slf-resistant cocci, which have distinct metabolic and resistance profiles, including resistance to cell wall antibiotics. Unlike dormant spores of P. dendritiformis, the cocci replicate. If cocci encounter conditions that favor rods, they secrete a signaling molecule that induces a switch to rods. Thus, in contrast to persister cells, P. dendritiformis bacteria adapt to changing environmental conditions by inducible and reversible phenotypic switching. In favorable environments, species may face space and nutrient limits due to overcrowding. Bacteria provide an excellent model for analyzing principles underlying overcrowding and regulation of density in nature, since their population dynamics can be easily and accurately assessed under controlled conditions. We describe a newly discovered mechanism for survival of a bacterial population during overcrowding. When competing with sibling colonies, Paenibacillus dendritiformis produces a lethal protein (Slf) that kills cells at the interface of encroaching colonies. Slf also induces a small proportion of the cells to switch from motile, rod-shaped cells to nonmotile, Slf-resistant, vegetative cocci. When crowding is reduced and nutrients are no longer limiting, the bacteria produce a signal that induces cocci to switch back to motile rods, allowing the population to spread. Genes encoding components of this phenotypic switching pathway are widespread among bacterial species, suggesting that this survival mechanism is not unique to P. dendritiformis.
Collapse
|
50
|
Watanabe T, Tanaka F, Uchino T. Development of Quantitative Biofilm Simulation Models Considering Mass Transfer at the Liquid-Biofilm Interface. J JPN SOC FOOD SCI 2011. [DOI: 10.3136/nskkk.58.318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|