1
|
Cheng Z, Stefani C, Skillman T, Klimas A, Lee A, DiBernardo EF, Brown KM, Milman T, Wang Y, Gallagher BR, Lagree K, Jena BP, Pulido JS, Filler SG, Mitchell AP, Hiller NL, Lacy‐Hulbert A, Zhao Y. MicroMagnify: A Multiplexed Expansion Microscopy Method for Pathogens and Infected Tissues. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2302249. [PMID: 37658522 PMCID: PMC10602566 DOI: 10.1002/advs.202302249] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 07/29/2023] [Indexed: 09/03/2023]
Abstract
Super-resolution optical imaging tools are crucial in microbiology to understand the complex structures and behavior of microorganisms such as bacteria, fungi, and viruses. However, the capabilities of these tools, particularly when it comes to imaging pathogens and infected tissues, remain limited. MicroMagnify (µMagnify) is developed, a nanoscale multiplexed imaging method for pathogens and infected tissues that are derived from an expansion microscopy technique with a universal biomolecular anchor. The combination of heat denaturation and enzyme cocktails essential is found for robust cell wall digestion and expansion of microbial cells and infected tissues without distortion. µMagnify efficiently retains biomolecules suitable for high-plex fluorescence imaging with nanoscale precision. It demonstrates up to eightfold expansion with µMagnify on a broad range of pathogen-containing specimens, including bacterial and fungal biofilms, infected culture cells, fungus-infected mouse tone, and formalin-fixed paraffin-embedded human cornea infected by various pathogens. Additionally, an associated virtual reality tool is developed to facilitate the visualization and navigation of complex 3D images generated by this method in an immersive environment allowing collaborative exploration among researchers worldwide. µMagnify is a valuable imaging platform for studying how microbes interact with their host systems and enables the development of new diagnosis strategies against infectious diseases.
Collapse
Affiliation(s)
- Zhangyu Cheng
- Department of Biological SciencesCarnegie Mellon University4400 Fifth AvenuePittsburghPA15213USA
| | - Caroline Stefani
- Benaroya Research Institute at Virginia Mason1201 9th AveSeattleWA98101USA
| | | | - Aleksandra Klimas
- Department of Biological SciencesCarnegie Mellon University4400 Fifth AvenuePittsburghPA15213USA
| | - Aramchan Lee
- Department of Biological SciencesCarnegie Mellon University4400 Fifth AvenuePittsburghPA15213USA
| | - Emma F. DiBernardo
- Department of Biological SciencesCarnegie Mellon University4400 Fifth AvenuePittsburghPA15213USA
| | - Karina Mueller Brown
- Department of Biological SciencesCarnegie Mellon University4400 Fifth AvenuePittsburghPA15213USA
| | - Tatyana Milman
- Wills Eye Hospital and Jefferson University HospitalPhiladelphiaPA19107USA
| | - Yuhong Wang
- Department of Biological SciencesCarnegie Mellon University4400 Fifth AvenuePittsburghPA15213USA
| | - Brendan R. Gallagher
- Department of Biological SciencesCarnegie Mellon University4400 Fifth AvenuePittsburghPA15213USA
| | - Katherine Lagree
- Department of Biological SciencesCarnegie Mellon University4400 Fifth AvenuePittsburghPA15213USA
| | - Bhanu P. Jena
- Viron Molecular Medicine Institute201 Washington StreetBostonMA02201USA
- Department of PhysiologyWayne State University42 W Warren AveDetroitMI48202USA
- NanoBioScience InstituteWayne State University42 W Warren AveDetroitMI48202USA
- Center for Molecular Medicine & GeneticsSchool of MedicineWayne State University42 W Warren AveDetroitMI48202USA
| | - Jose S. Pulido
- Wills Eye Hospital and Jefferson University HospitalPhiladelphiaPA19107USA
| | - Scott G. Filler
- Lundquist Institute for Biomedical Innovation at Harbor‐UCLA Medical Center1124 W Carson StTorranceCA90502USA
- David Geffen School of Medicine at UCLA10833 Le Conte AveLos AngelesCA90095USA
| | - Aaron P. Mitchell
- Department of Biological SciencesCarnegie Mellon University4400 Fifth AvenuePittsburghPA15213USA
- Department of MicrobiologyUniversity of Georgia210 S Jackson streetAthensGA30602USA
| | - N. Luisa Hiller
- Department of Biological SciencesCarnegie Mellon University4400 Fifth AvenuePittsburghPA15213USA
| | - Adam Lacy‐Hulbert
- Benaroya Research Institute at Virginia Mason1201 9th AveSeattleWA98101USA
| | - Yongxin Zhao
- Department of Biological SciencesCarnegie Mellon University4400 Fifth AvenuePittsburghPA15213USA
| |
Collapse
|
2
|
Hardy E, Sarker H, Fernandez-Patron C. Could a Non-Cellular Molecular Interactome in the Blood Circulation Influence Pathogens' Infectivity? Cells 2023; 12:1699. [PMID: 37443732 PMCID: PMC10341357 DOI: 10.3390/cells12131699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 06/14/2023] [Accepted: 06/19/2023] [Indexed: 07/15/2023] Open
Abstract
We advance the notion that much like artificial nanoparticles, relatively more complex biological entities with nanometric dimensions such as pathogens (viruses, bacteria, and other microorganisms) may also acquire a biomolecular corona upon entering the blood circulation of an organism. We view this biomolecular corona as a component of a much broader non-cellular blood interactome that can be highly specific to the organism, akin to components of the innate immune response to an invading pathogen. We review published supporting data and generalize these notions from artificial nanoparticles to viruses and bacteria. Characterization of the non-cellular blood interactome of an organism may help explain apparent differences in the susceptibility to pathogens among individuals. The non-cellular blood interactome is a candidate therapeutic target to treat infectious and non-infectious conditions.
Collapse
Affiliation(s)
- Eugenio Hardy
- Center of Molecular Immunology, P.O. Box 16040, Havana 11600, Cuba
| | - Hassan Sarker
- Department of Biochemistry, Faculty of Medicine and Dentistry, College of Health Sciences, University of Alberta, Edmonton, AB T6G 2H7, Canada;
| | - Carlos Fernandez-Patron
- Department of Biochemistry, Faculty of Medicine and Dentistry, College of Health Sciences, University of Alberta, Edmonton, AB T6G 2H7, Canada;
| |
Collapse
|
3
|
Salamaga B, Turner RD, Elsarmane F, Galley NF, Kulakauskas S, Mesnage S. A moonlighting role for LysM peptidoglycan binding domains underpins Enterococcus faecalis daughter cell separation. Commun Biol 2023; 6:428. [PMID: 37072531 PMCID: PMC10113225 DOI: 10.1038/s42003-023-04808-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 04/04/2023] [Indexed: 04/20/2023] Open
Abstract
Control of cell size and morphology is of paramount importance for bacterial fitness. In the opportunistic pathogen Enterococcus faecalis, the formation of diplococci and short cell chains facilitates innate immune evasion and dissemination in the host. Minimisation of cell chain size relies on the activity of a peptidoglycan hydrolase called AtlA, dedicated to septum cleavage. To prevent autolysis, AtlA activity is tightly controlled, both temporally and spatially. Here, we show that the restricted localization of AtlA at the septum occurs via an unexpected mechanism. We demonstrate that the C-terminal LysM domain that allows the enzyme to bind peptidoglycan is essential to target this enzyme to the septum inside the cell before its translocation across the membrane. We identify a membrane-bound cytoplasmic protein partner (called AdmA) involved in the recruitment of AtlA via its LysM domains. This work reveals a moonlighting role for LysM domains, and a mechanism evolved to restrict the subcellular localization of a potentially lethal autolysin to its site of action.
Collapse
Affiliation(s)
| | - Robert D Turner
- School of Biosciences, University of Sheffield, Sheffield, UK
| | - Fathe Elsarmane
- School of Biosciences, University of Sheffield, Sheffield, UK
| | - Nicola F Galley
- School of Biosciences, University of Sheffield, Sheffield, UK
| | - Saulius Kulakauskas
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
| | | |
Collapse
|
4
|
Hector TE, Gehman ALM, King KC. Infection burdens and virulence under heat stress: ecological and evolutionary considerations. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220018. [PMID: 36744570 PMCID: PMC9900716 DOI: 10.1098/rstb.2022.0018] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 12/17/2022] [Indexed: 02/07/2023] Open
Abstract
As a result of global change, hosts and parasites (including pathogens) are experiencing shifts in their thermal environment. Despite the importance of heat stress tolerance for host population persistence, infection by parasites can impair a host's ability to cope with heat. Host-parasite eco-evolutionary dynamics will be affected if infection reduces host performance during heating. Theory predicts that within-host parasite burden (replication rate or number of infecting parasites per host), a key component of parasite fitness, should correlate positively with virulence-the harm caused to hosts during infection. Surprisingly, however, the relationship between within-host parasite burden and virulence during heating is often weak. Here, we describe the current evidence for the link between within-host parasite burden and host heat stress tolerance. We consider the biology of host-parasite systems that may explain the weak or absent link between these two important host and parasite traits during hot conditions. The processes that mediate the relationship between parasite burden and host fitness will be fundamental in ecological and evolutionary responses of host and parasites in a warming world. This article is part of the theme issue 'Infectious disease ecology and evolution in a changing world'.
Collapse
Affiliation(s)
- T. E. Hector
- Department of Biology, University of Oxford, Oxford, Oxfordshire OX1 3SZ, UK
| | - A.-L. M. Gehman
- Hakai Institute, End of Kwakshua Channel, Calvert Island, BC Canada, V0N 1M0
- Institute for the Oceans and Fisheries, University of British Columbia, 2202 Main Mall, Vancouver, BC Canada, V6T 1Z4
| | - K. C. King
- Department of Biology, University of Oxford, Oxford, Oxfordshire OX1 3SZ, UK
| |
Collapse
|
5
|
Zhao Y, Cheng Z, Stefani C, Skillman T, Klimas A, Lee A, DiBernardo E, Mueller Brown K, Milman T, Gallagher B, Lagree K, Jena B, Pulido J, Filler S, Mitchell A, Hiller L, Lacy-Hulbert A. MicroMagnify: a multiplexed expansion microscopy method for pathogens and infected tissues. RESEARCH SQUARE 2023:rs.3.rs-2637060. [PMID: 36945526 PMCID: PMC10029075 DOI: 10.21203/rs.3.rs-2637060/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/08/2023]
Abstract
Super-resolution optical imaging tools are crucial in microbiology to understand the complex structures and behavior of microorganisms such as bacteria, fungi, and viruses. However, the capabilities of these tools, particularly when it comes to imaging pathogens and infected tissues, remain limited. We developed µMagnify, a nanoscale multiplexed imaging method for pathogens and infected tissues that are derived from an expansion microscopy technique with a universal biomolecular anchor. We formulated an enzyme cocktail specifically designed for robust cell wall digestion and expansion of microbial cells without distortion while efficiently retaining biomolecules suitable for high-plex fluorescence imaging with nanoscale precision. Additionally, we developed an associated virtual reality tool to facilitate the visualization and navigation of complex three-dimensional images generated by this method in an immersive environment allowing collaborative exploration among researchers around the world. µMagnify is a valuable imaging platform for studying how microbes interact with their host systems and enables development of new diagnosis strategies against infectious diseases.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | - Bhanu Jena
- Wayne State University School of Medicine
| | - Jose Pulido
- Wills Eye Hospital and Jefferson University Hospital
| | - Scott Filler
- Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center
| | | | | | | |
Collapse
|
6
|
Sayed FAZ, Eissa NG, Shen Y, Hunstad DA, Wooley KL, Elsabahy M. Morphologic design of nanostructures for enhanced antimicrobial activity. J Nanobiotechnology 2022; 20:536. [PMID: 36539809 PMCID: PMC9768920 DOI: 10.1186/s12951-022-01733-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 11/29/2022] [Indexed: 12/24/2022] Open
Abstract
Despite significant progress in synthetic polymer chemistry and in control over tuning the structures and morphologies of nanoparticles, studies on morphologic design of nanomaterials for the purpose of optimizing antimicrobial activity have yielded mixed results. When designing antimicrobial materials, it is important to consider two distinctly different modes and mechanisms of activity-those that involve direct interactions with bacterial cells, and those that promote the entry of nanomaterials into infected host cells to gain access to intracellular pathogens. Antibacterial activity of nanoparticles may involve direct interactions with organisms and/or release of antibacterial cargo, and these activities depend on attractive interactions and contact areas between particles and bacterial or host cell surfaces, local curvature and dynamics of the particles, all of which are functions of nanoparticle shape. Bacteria may exist as spheres, rods, helices, or even in uncommon shapes (e.g., box- and star-shaped) and, furthermore, may transform into other morphologies along their lifespan. For bacteria that invade host cells, multivalent interactions are involved and are dependent upon bacterial size and shape. Therefore, mimicking bacterial shapes has been hypothesized to impact intracellular delivery of antimicrobial nanostructures. Indeed, designing complementarities between the shapes of microorganisms with nanoparticle platforms that are designed for antimicrobial delivery offers interesting new perspectives toward future nanomedicines. Some studies have reported improved antimicrobial activities with spherical shapes compared to non-spherical constructs, whereas other studies have reported higher activity for non-spherical structures (e.g., rod, discoid, cylinder, etc.). The shapes of nano- and microparticles have also been shown to impact their rates and extents of uptake by mammalian cells (macrophages, epithelial cells, and others). However, in most of these studies, nanoparticle morphology was not intentionally designed to mimic specific bacterial shape. Herein, the morphologic designs of nanoparticles that possess antimicrobial activities per se and those designed to deliver antimicrobial agent cargoes are reviewed. Furthermore, hypotheses beyond shape dependence and additional factors that help to explain apparent discrepancies among studies are highlighted.
Collapse
Affiliation(s)
- Fatma Al-Zahraa Sayed
- grid.507995.70000 0004 6073 8904School of Biotechnology, Science Academy, Badr University in Cairo, Badr City, Cairo, 11829 Egypt
| | - Noura G. Eissa
- grid.507995.70000 0004 6073 8904School of Biotechnology, Science Academy, Badr University in Cairo, Badr City, Cairo, 11829 Egypt ,grid.31451.320000 0001 2158 2757Department of Pharmaceutics, Faculty of Pharmacy, Zagazig University, Zagazig, 44519 Egypt
| | - Yidan Shen
- grid.264756.40000 0004 4687 2082Departments of Chemistry, Materials Science and Engineering, and Chemical Engineering, Texas A&M University, College Station, TX 77842 USA
| | - David A. Hunstad
- grid.4367.60000 0001 2355 7002Departments of Pediatrics and Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110 USA
| | - Karen L. Wooley
- grid.264756.40000 0004 4687 2082Departments of Chemistry, Materials Science and Engineering, and Chemical Engineering, Texas A&M University, College Station, TX 77842 USA
| | - Mahmoud Elsabahy
- grid.507995.70000 0004 6073 8904School of Biotechnology, Science Academy, Badr University in Cairo, Badr City, Cairo, 11829 Egypt ,grid.264756.40000 0004 4687 2082Departments of Chemistry, Materials Science and Engineering, and Chemical Engineering, Texas A&M University, College Station, TX 77842 USA ,grid.440875.a0000 0004 1765 2064Misr University for Science and Technology, 6th of October City, Cairo, 12566 Egypt
| |
Collapse
|
7
|
Argyropoulos CD, Skoulou V, Efthimiou G, Michopoulos AK. Airborne transmission of biological agents within the indoor built environment: a multidisciplinary review. AIR QUALITY, ATMOSPHERE, & HEALTH 2022; 16:477-533. [PMID: 36467894 PMCID: PMC9703444 DOI: 10.1007/s11869-022-01286-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 11/17/2022] [Indexed: 06/17/2023]
Abstract
The nature and airborne dispersion of the underestimated biological agents, monitoring, analysis and transmission among the human occupants into building environment is a major challenge of today. Those agents play a crucial role in ensuring comfortable, healthy and risk-free conditions into indoor working and leaving spaces. It is known that ventilation systems influence strongly the transmission of indoor air pollutants, with scarce information although to have been reported for biological agents until 2019. The biological agents' source release and the trajectory of airborne transmission are both important in terms of optimising the design of the heating, ventilation and air conditioning systems of the future. In addition, modelling via computational fluid dynamics (CFD) will become a more valuable tool in foreseeing risks and tackle hazards when pollutants and biological agents released into closed spaces. Promising results on the prediction of their dispersion routes and concentration levels, as well as the selection of the appropriate ventilation strategy, provide crucial information on risk minimisation of the airborne transmission among humans. Under this context, the present multidisciplinary review considers four interrelated aspects of the dispersion of biological agents in closed spaces, (a) the nature and airborne transmission route of the examined agents, (b) the biological origin and health effects of the major microbial pathogens on the human respiratory system, (c) the role of heating, ventilation and air-conditioning systems in the airborne transmission and (d) the associated computer modelling approaches. This adopted methodology allows the discussion of the existing findings, on-going research, identification of the main research gaps and future directions from a multidisciplinary point of view which will be helpful for substantial innovations in the field.
Collapse
Affiliation(s)
| | - Vasiliki Skoulou
- B3 Challenge Group, Chemical Engineering, School of Engineering, University of Hull, Cottingham Road, Hull, HU6 7RX UK
| | - Georgios Efthimiou
- Centre for Biomedicine, Hull York Medical School, University of Hull, Cottingham Road, Hull, HU6 7RX UK
| | - Apostolos K. Michopoulos
- Energy & Environmental Design of Buildings Research Laboratory, University of Cyprus, P.O. Box 20537, 1678 Nicosia, Cyprus
| |
Collapse
|
8
|
Zhang X, Feng H, He J, Muhammad A, Zhang F, Lu X. Features and Colonization Strategies of Enterococcus faecalis in the Gut of Bombyx mori. Front Microbiol 2022; 13:921330. [PMID: 35814682 PMCID: PMC9263704 DOI: 10.3389/fmicb.2022.921330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 06/08/2022] [Indexed: 11/30/2022] Open
Abstract
The complex gut microbiome is a malleable microbial community that can undergo remodeling in response to many factors, including the gut environment and microbial properties. Enterococcus has emerged as one of the predominant gut commensal bacterial and plays a fundamental role in the host physiology and health of the major economic agricultural insect, Bombyx mori. Although extensive research on gut structure and microbiome diversity has been carried out, how these microbial consortia are established in multifarious niches within the gut has not been well characterized to date. Here, an Enterococcus species that was stably associated with its host, the model organism B. mori, was identified in the larval gut. GFP–tagged E. faecalis LX10 was constructed as a model bacterium to track the colonization mechanism in the intestine of B. mori. The results revealed that the minimum and optimum colonization results were obtained by feeding at doses of 105 CFU/silkworm and 107 CFU/silkworm, respectively, as confirmed by bioassays and fluorescence-activated cell sorting analyses (FACS). Furthermore, a comprehensive genome-wide exploration of signal sequences provided insight into the relevant colonization properties of E. faecalis LX10. E. faecalis LX10 grew well under alkaline conditions and stably reduced the intestinal pH through lactic acid production. Additionally, the genomic features responsible for lactic acid fermentation were characterized. We further expressed and purified E. faecalis bacteriocin and found that it was particularly effective against other gut bacteria, including Enterococcus casselifavus, Enterococcus mundtii, Serratia marcescens, Bacillus amyloliquefaciens, and Escherichia coli. In addition, the successful colonization of E. faecalis LX10 led to drastically increased expression of all adhesion genes (znuA, lepB, hssA, adhE, EbpA, and Lap), defense genes (cspp, tagF, and esp), regulation gene (BfmRS), secretion gene (prkC) and immune evasion genes (patA and patB), while the expression of iron acquisition genes (ddpD and metN) was largely unchanged or decreased. This work establishes an unprecedented conceptual model for understanding B. mori–gut microbiota interactions in an ecological context. Moreover, these results shed light on the molecular mechanisms of gut microbiota proliferation and colonization in the intestinal tract of this insect.
Collapse
Affiliation(s)
- Xiancui Zhang
- College of Animal Sciences, Institute of Sericulture and Apiculture, Zhejiang University, Hangzhou, China
| | - Huihui Feng
- College of Animal Sciences, Institute of Sericulture and Apiculture, Zhejiang University, Hangzhou, China
| | - Jintao He
- College of Animal Sciences, Institute of Sericulture and Apiculture, Zhejiang University, Hangzhou, China
| | - Abrar Muhammad
- College of Animal Sciences, Institute of Sericulture and Apiculture, Zhejiang University, Hangzhou, China
| | - Fan Zhang
- Key Laboratory of Animal Resistance Biology of Shandong Province, College of Life Science, Shandong Normal University, Jinan, China
- *Correspondence: Fan Zhang,
| | - Xingmeng Lu
- College of Animal Sciences, Institute of Sericulture and Apiculture, Zhejiang University, Hangzhou, China
- Xingmeng Lu,
| |
Collapse
|
9
|
Gilmore MC, Ritzl-Rinkenberger B, Cava F. An updated toolkit for exploring bacterial cell wall structure and dynamics. Fac Rev 2021; 10:14. [PMID: 33659932 PMCID: PMC7894271 DOI: 10.12703/r/10-14] [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: 11/15/2022] Open
Abstract
The bacterial cell wall is made primarily from peptidoglycan, a complex biomolecule which forms a bag-like exoskeleton that envelops the cell. As it is unique to bacteria and typically essential for their growth and survival, it represents one of the most successful targets for antibiotics. Although peptidoglycan has been studied intensively for over 50 years, the past decade has seen major steps in our understanding of this molecule because of the advent of new analytical and imaging methods. Here, we outline the most recent developments in tools that have helped to elucidate peptidoglycan structure and dynamics.
Collapse
Affiliation(s)
- Michael C Gilmore
- Laboratory for Molecular Infection Medicine Sweden (MIMS), Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Barbara Ritzl-Rinkenberger
- Laboratory for Molecular Infection Medicine Sweden (MIMS), Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Felipe Cava
- Laboratory for Molecular Infection Medicine Sweden (MIMS), Department of Molecular Biology, Umeå University, Umeå, Sweden
| |
Collapse
|
10
|
Anuj SA, Gajera HP, Hirpara DG, Golakiya BA. The impact of bacterial size on their survival in the presence of cationic particles of nano-silver. J Trace Elem Med Biol 2020; 61:126517. [PMID: 32447152 DOI: 10.1016/j.jtemb.2020.126517] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 03/19/2020] [Accepted: 03/30/2020] [Indexed: 12/27/2022]
Abstract
BACKGROUND Microbial surface area is one of the battlegrounds for invading microbes and host defense. Hence, infectious diseases caused by drug resistant microbes with large surface area are more difficult to treat than small size microbes. Nanobiology offers opportunities to re-explore the biological properties of conventional drugs at molecular level to combat these microbes. The purpose of the present study was to examine size depended susceptibility of Gram-positive bacteria towards nano-silver particles. METHODS This study investigated the growth, surface charge, and morphology of emerging B. megaterium MTCC 7192 and re-emerging S. aureus MTCC 3160 cells in order to observe the susceptibility of these bacteria towards cationic nano-silver particles. Nano-silver particles were applied into wells formed on the Nutrient agar plates containing 108 CFU/mL of the bacteria. Surface potential of normal and treated cells was measured by Microtrac and the effects of nano-silver particles on bacterial cells were assessed by Scanning Electron Microscopy (SEM). RESULTS In this work, synthesized nano-silver particles were found to be more effective against B. megaterium MTCC 7192 than S. aureus MTCC 3160. For B. megaterium MTCC 7192, a 0.30 fold increase in inhibition zone was observed after the addition of nano-silver particles in the wells. From our studies, it is reasonable to state that alternation of zeta potential may affect the cell morphology, which was further confirmed by SEM. CONCLUSION The present study concluded that nano-silver particles appears to interact with a larger surface area more effectively.
Collapse
Affiliation(s)
- Samir A Anuj
- School of Science, RK University, Rajkot, 360020, Gujarat, India.
| | - Harsukh P Gajera
- Department of Biotechnology, College of Agriculture, Junagadh Agricultural University, Junagadh, 362001, Gujarat, India
| | - Darshna G Hirpara
- Department of Biotechnology, College of Agriculture, Junagadh Agricultural University, Junagadh, 362001, Gujarat, India
| | - Baljibhai A Golakiya
- Department of Biotechnology, College of Agriculture, Junagadh Agricultural University, Junagadh, 362001, Gujarat, India
| |
Collapse
|
11
|
Regulation of filamentation by bacteria and its impact on the productivity of compounds in biotechnological processes. Appl Microbiol Biotechnol 2020; 104:4631-4642. [DOI: 10.1007/s00253-020-10590-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 03/18/2020] [Accepted: 03/25/2020] [Indexed: 12/29/2022]
|
12
|
Hassan AA, Vitorino MV, Robalo T, Rodrigues MS, Sá-Correia I. Variation of Burkholderia cenocepacia cell wall morphology and mechanical properties during cystic fibrosis lung infection, assessed by atomic force microscopy. Sci Rep 2019; 9:16118. [PMID: 31695169 PMCID: PMC6834607 DOI: 10.1038/s41598-019-52604-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 10/21/2019] [Indexed: 12/13/2022] Open
Abstract
The influence that Burkholderia cenocepacia adaptive evolution during long-term infection in cystic fibrosis (CF) patients has on cell wall morphology and mechanical properties is poorly understood despite their crucial role in cell physiology, persistent infection and pathogenesis. Cell wall morphology and physical properties of three B. cenocepacia isolates collected from a CF patient over a period of 3.5 years were compared using atomic force microscopy (AFM). These serial clonal variants include the first isolate retrieved from the patient and two late isolates obtained after three years of infection and before the patient's death with cepacia syndrome. A consistent and progressive decrease of cell height and a cell shape evolution during infection, from the typical rods to morphology closer to cocci, were observed. The images of cells grown in biofilms showed an identical cell size reduction pattern. Additionally, the apparent elasticity modulus significantly decreases from the early isolate to the last clonal variant retrieved from the patient but the intermediary highly antibiotic resistant clonal isolate showed the highest elasticity values. Concerning the adhesion of bacteria surface to the AFM tip, the first isolate was found to adhere better than the late isolates whose lipopolysaccharide (LPS) structure loss the O-antigen (OAg) during CF infection. The OAg is known to influence Gram-negative bacteria adhesion and be an important factor in B. cenocepacia adaptation to chronic infection. Results reinforce the concept of the occurrence of phenotypic heterogeneity and adaptive evolution, also at the level of cell size, form, envelope topography and physical properties during long-term infection.
Collapse
Affiliation(s)
- A Amir Hassan
- iBB - Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, 1049-001, Portugal
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, 1049-001, Portugal
| | - Miguel V Vitorino
- BioISI - Biosystems and Integrative Sciences Institute, Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisboa, Portugal
- Departamento de Física, Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisboa, Portugal
| | - Tiago Robalo
- BioISI - Biosystems and Integrative Sciences Institute, Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisboa, Portugal
| | - Mário S Rodrigues
- BioISI - Biosystems and Integrative Sciences Institute, Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisboa, Portugal.
- Departamento de Física, Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisboa, Portugal.
| | - Isabel Sá-Correia
- iBB - Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, 1049-001, Portugal.
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, 1049-001, Portugal.
| |
Collapse
|
13
|
Zahir T, Camacho R, Vitale R, Ruckebusch C, Hofkens J, Fauvart M, Michiels J. High-throughput time-resolved morphology screening in bacteria reveals phenotypic responses to antibiotics. Commun Biol 2019; 2:269. [PMID: 31341968 PMCID: PMC6650389 DOI: 10.1038/s42003-019-0480-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Accepted: 05/21/2019] [Indexed: 11/09/2022] Open
Abstract
Image-based high-throughput screening strategies for quantifying morphological phenotypes have proven widely successful. Here we describe a combined experimental and multivariate image analysis approach for systematic large-scale phenotyping of morphological dynamics in bacteria. Using off-the-shelf components and software, we established a workflow for high-throughput time-resolved microscopy. We then screened the single-gene deletion collection of Escherichia coli for antibiotic-induced morphological changes. Using single-cell quantitative descriptors and supervised classification methods, we measured how different cell morphologies developed over time for all strains in response to the β-lactam antibiotic cefsulodin. 191 strains exhibit significant variations under antibiotic treatment. Phenotypic clustering provided insights into processes that alter the antibiotic response. Mutants with stable bulges show delayed lysis, contributing to antibiotic tolerance. Lipopolysaccharides play a crucial role in bulge stability. This study demonstrates how multiparametric phenotyping by high-throughput time-resolved imaging and computer-aided cell classification can be used for comprehensively studying dynamic morphological transitions in bacteria.
Collapse
Affiliation(s)
- Taiyeb Zahir
- Centre of Microbial and Plant Genetics, KU Leuven—University of Leuven, Leuven, 3001 Belgium
- VIB-KU Leuven Center of Microbiology, Leuven, 3001 Belgium
| | - Rafael Camacho
- Department of Chemistry, KU Leuven—University of Leuven, Leuven, 3001 Belgium
| | - Raffaele Vitale
- Department of Chemistry, KU Leuven—University of Leuven, Leuven, 3001 Belgium
- LASIR CNRS, Université de Lille, Lille, F-59000 France
| | | | - Johan Hofkens
- Department of Chemistry, KU Leuven—University of Leuven, Leuven, 3001 Belgium
| | - Maarten Fauvart
- Centre of Microbial and Plant Genetics, KU Leuven—University of Leuven, Leuven, 3001 Belgium
- VIB-KU Leuven Center of Microbiology, Leuven, 3001 Belgium
- imec, Leuven, 3001 Belgium
| | - Jan Michiels
- Centre of Microbial and Plant Genetics, KU Leuven—University of Leuven, Leuven, 3001 Belgium
- VIB-KU Leuven Center of Microbiology, Leuven, 3001 Belgium
| |
Collapse
|
14
|
Intestinal Bile Acids Induce a Morphotype Switch in Vancomycin-Resistant Enterococcus that Facilitates Intestinal Colonization. Cell Host Microbe 2019; 25:695-705.e5. [PMID: 31031170 DOI: 10.1016/j.chom.2019.03.008] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 01/25/2019] [Accepted: 03/18/2019] [Indexed: 12/22/2022]
Abstract
Vancomycin-resistant Enterococcus (VRE) are highly antibiotic-resistant and readily transmissible pathogens that cause severe infections in hospitalized patients. We discovered that lithocholic acid (LCA), a secondary bile acid prevalent in the cecum and colon of mice and humans, impairs separation of growing VRE diplococci, causing the formation of long chains and increased biofilm formation. Divalent cations reversed this LCA-induced switch to chaining and biofilm formation. Experimental evolution in the presence of LCA yielded mutations in the essential two-component kinase yycG/walK and three-component response regulator liaR that locked VRE in diplococcal mode, impaired biofilm formation, and increased susceptibility to the antibiotic daptomycin. These mutant VRE strains were deficient in host colonization because of their inability to compete with intestinal microbiota. This morphotype switch presents a potential non-bactericidal therapeutic target that may help clear VRE from the intestines of dominated patients, as occurs frequently during hematopoietic stem cell transplantation.
Collapse
|
15
|
Impact of Membrane Phospholipid Alterations in Escherichia coli on Cellular Function and Bacterial Stress Adaptation. J Bacteriol 2017; 199:JB.00849-16. [PMID: 28439040 DOI: 10.1128/jb.00849-16] [Citation(s) in RCA: 149] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 04/20/2017] [Indexed: 11/20/2022] Open
Abstract
Bacteria have evolved multiple strategies to sense and rapidly adapt to challenging and ever-changing environmental conditions. The ability to alter membrane lipid composition, a key component of the cellular envelope, is crucial for bacterial survival and adaptation in response to environmental stress. However, the precise roles played by membrane phospholipids in bacterial physiology and stress adaptation are not fully elucidated. The goal of this study was to define the role of membrane phospholipids in adaptation to stress and maintenance of bacterial cell fitness. By using genetically modified strains in which the membrane phospholipid composition can be systematically manipulated, we show that alterations in major Escherichia coli phospholipids transform these cells globally. We found that alterations in phospholipids impair the cellular envelope structure and function, the ability to form biofilms, and bacterial fitness and cause phospholipid-dependent susceptibility to environmental stresses. This study provides an unprecedented view of the structural, signaling, and metabolic pathways in which bacterial phospholipids participate, allowing the design of new approaches in the investigation of lipid-dependent processes involved in bacterial physiology and adaptation.IMPORTANCE In order to cope with and adapt to a wide range of environmental conditions, bacteria have to sense and quickly respond to fluctuating conditions. In this study, we investigated the effects of systematic and controlled alterations in bacterial phospholipids on cell shape, physiology, and stress adaptation. We provide new evidence that alterations of specific phospholipids in Escherichia coli have detrimental effects on cellular shape, envelope integrity, and cell physiology that impair biofilm formation, cellular envelope remodeling, and adaptability to environmental stresses. These findings hold promise for future antibacterial therapies that target bacterial lipid biosynthesis.
Collapse
|
16
|
Itzek A, Chen Z, Merritt J, Kreth J. Effect of salivary agglutination on oral streptococcal clearance by human polymorphonuclear neutrophil granulocytes. Mol Oral Microbiol 2017; 32:197-210. [PMID: 27194631 PMCID: PMC5116291 DOI: 10.1111/omi.12164] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/14/2016] [Indexed: 12/20/2022]
Abstract
Salivary agglutination is an important host defense mechanism to aggregate oral commensal bacteria as well as invading pathogens. Saliva flow and subsequent swallowing more easily clear aggregated bacteria compared with single cells. Phagocytic clearance of bacteria through polymorphonuclear neutrophil granulocytes also seems to increase to a certain extent with the size of bacterial aggregates. To determine a connection between salivary agglutination and the host innate immune response by phagocytosis, an in vitro agglutination assay was developed reproducing the average size of salivary bacterial aggregates. Using the oral commensal Streptococcus gordonii as a model organism, the effect of salivary agglutination on phagocytic clearance through polymorphonuclear neutrophil granulocytes was investigated. Here we describe how salivary aggregates of S. gordonii are readily cleared through phagocytosis, whereas single bacterial cells showed a significant delay in being phagocytosed and killed. Furthermore, before phagocytosis the polymorphonuclear neutrophil granulocytes were able to induce a specific de-aggregation, which was dependent on serine protease activity. The data presented suggest that salivary agglutination of bacterial cells leads to an ideal size for recognition by polymorphonuclear neutrophil granulocytes. As a first line of defense, these phagocytic cells are able to recognize the aggregates and de-aggregate them via serine proteases to a more manageable size for efficient phagocytosis and subsequent killing in the phagolysosome. This observed mechanism not only prevents the rapid spreading of oral bacterial cells while entering the bloodstream but would also avoid degranulation of involved polymorphonuclear neutrophil granulocytes, so preventing collateral damage to nearby tissue.
Collapse
Affiliation(s)
- Andreas Itzek
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Zhiyun Chen
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Justin Merritt
- Department of Restorative Dentistry, Oregon Health and Science University, Portland, OR, USA
| | - Jens Kreth
- Department of Restorative Dentistry, Oregon Health and Science University, Portland, OR, USA
| |
Collapse
|
17
|
Crosby HA, Kwiecinski J, Horswill AR. Staphylococcus aureus Aggregation and Coagulation Mechanisms, and Their Function in Host-Pathogen Interactions. ADVANCES IN APPLIED MICROBIOLOGY 2016; 96:1-41. [PMID: 27565579 DOI: 10.1016/bs.aambs.2016.07.018] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The human commensal bacterium Staphylococcus aureus can cause a wide range of infections ranging from skin and soft tissue infections to invasive diseases like septicemia, endocarditis, and pneumonia. Muticellular organization almost certainly contributes to S. aureus pathogenesis mechanisms. While there has been considerable focus on biofilm formation and its role in colonizing prosthetic joints and indwelling devices, less attention has been paid to nonsurface-attached group behavior like aggregation and clumping. S. aureus is unique in its ability to coagulate blood, and it also produces multiple fibrinogen-binding proteins that facilitate clumping. Formation of clumps, which are large, tightly packed groups of cells held together by fibrin(ogen), has been demonstrated to be important for S. aureus virulence and immune evasion. Clumps of cells are able to avoid detection by the host's immune system due to a fibrin(ogen) coat that acts as a shield, and the size of the clumps facilitates evasion of phagocytosis. In addition, clumping could be an important early step in establishing infections that involve tight clusters of cells embedded in host matrix proteins, such as soft tissue abscesses and endocarditis. In this review, we discuss clumping mechanisms and regulation, as well as what is known about how clumping contributes to immune evasion.
Collapse
Affiliation(s)
- H A Crosby
- University of Iowa, Iowa City, IA, United States
| | - J Kwiecinski
- University of Iowa, Iowa City, IA, United States
| | - A R Horswill
- University of Iowa, Iowa City, IA, United States
| |
Collapse
|
18
|
Iovino F, Hammarlöf DL, Garriss G, Brovall S, Nannapaneni P, Henriques-Normark B. Pneumococcal meningitis is promoted by single cocci expressing pilus adhesin RrgA. J Clin Invest 2016; 126:2821-6. [PMID: 27348589 DOI: 10.1172/jci84705] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 05/05/2016] [Indexed: 01/15/2023] Open
Abstract
Streptococcus pneumoniae (pneumococcus) is the primary cause of bacterial meningitis. Pneumococcal bacteria penetrates the blood-brain barrier (BBB), but the bacterial factors that enable this process are not known. Here, we determined that expression of pneumococcal pilus-1, which includes the pilus adhesin RrgA, promotes bacterial penetration through the BBB in a mouse model. S. pneumoniae that colonized the respiratory epithelium and grew in the bloodstream were chains of variable lengths; however, the pneumococci that entered the brain were division-competent, spherical, single cocci that expressed adhesive RrgA-containing pili. The cell division protein DivIVA, which is required for an ovoid shape, was localized at the poles and septum of pneumococcal chains of ovoid, nonseparated bacteria, but was absent in spherical, single cocci. In the bloodstream, a small percentage of pneumococci appeared as piliated, RrgA-expressing, DivIVA-negative single cocci, suggesting that only a minority of S. pneumoniae are poised to cross the BBB. Together, our data indicate that small bacterial cell size, which is signified by the absence of DivIVA, and the presence of an adhesive RrgA-containing pilus-1 mediate pneumococcal passage from the bloodstream through the BBB into the brain to cause lethal meningitis.
Collapse
|
19
|
Tsui HCT, Zheng JJ, Magallon AN, Ryan JD, Yunck R, Rued BE, Bernhardt TG, Winkler ME. Suppression of a deletion mutation in the gene encoding essential PBP2b reveals a new lytic transglycosylase involved in peripheral peptidoglycan synthesis in Streptococcus pneumoniae D39. Mol Microbiol 2016; 100:1039-65. [PMID: 26933838 DOI: 10.1111/mmi.13366] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
In ellipsoid-shaped ovococcus bacteria, such as the pathogen Streptococcus pneumoniae (pneumococcus), side-wall (peripheral) peptidoglycan (PG) synthesis emanates from midcells and is catalyzed by the essential class B penicillin-binding protein PBP2b transpeptidase (TP). We report that mutations that inactivate the pneumococcal YceG-domain protein, Spd_1346 (renamed MltG), remove the requirement for PBP2b. ΔmltG mutants in unencapsulated strains accumulate inactivation mutations of class A PBP1a, which possesses TP and transglycosylase (TG) activities. The 'synthetic viable' genetic relationship between Δpbp1a and ΔmltG mutations extends to essential ΔmreCD and ΔrodZ mutations that misregulate peripheral PG synthesis. Remarkably, the single MltG(Y488D) change suppresses the requirement for PBP2b, MreCD, RodZ and RodA. Structural modeling and comparisons, catalytic-site changes and an interspecies chimera indicate that pneumococcal MltG is the functional homologue of the recently reported MltG endo-lytic transglycosylase of Escherichia coli. Depletion of pneumococcal MltG or mltG(Y488D) increases sphericity of cells, and MltG localizes with peripheral PG synthesis proteins during division. Finally, growth of Δpbp1a ΔmltG or mltG(Y488D) mutants depends on induction of expression of the WalRK TCS regulon of PG hydrolases. These results fit a model in which MltG releases anchored PG glycan strands synthesized by PBP1a for crosslinking by a PBP2b:RodA complex in peripheral PG synthesis.
Collapse
Affiliation(s)
| | - Jiaqi J Zheng
- Department of Biology, Indiana University Bloomington, Bloomington, IN, 47405, USA
| | - Ariel N Magallon
- Department of Biology, Indiana University Bloomington, Bloomington, IN, 47405, USA
| | - John D Ryan
- Department of Biology, Indiana University Bloomington, Bloomington, IN, 47405, USA
| | - Rachel Yunck
- Department of Microbiology and Immunology, Harvard Medical School, Boston, MA, 02115, USA
| | - Britta E Rued
- Department of Biology, Indiana University Bloomington, Bloomington, IN, 47405, USA
| | - Thomas G Bernhardt
- Department of Microbiology and Immunology, Harvard Medical School, Boston, MA, 02115, USA
| | - Malcolm E Winkler
- Department of Biology, Indiana University Bloomington, Bloomington, IN, 47405, USA
| |
Collapse
|
20
|
Staying in Shape: the Impact of Cell Shape on Bacterial Survival in Diverse Environments. Microbiol Mol Biol Rev 2016; 80:187-203. [PMID: 26864431 DOI: 10.1128/mmbr.00031-15] [Citation(s) in RCA: 161] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Bacteria display an abundance of cellular forms and can change shape during their life cycle. Many plausible models regarding the functional significance of cell morphology have emerged. A greater understanding of the genetic programs underpinning morphological variation in diverse bacterial groups, combined with assays of bacteria under conditions that mimic their varied natural environments, from flowing freshwater streams to diverse human body sites, provides new opportunities to probe the functional significance of cell shape. Here we explore shape diversity among bacteria, at the levels of cell geometry, size, and surface appendages (both placement and number), as it relates to survival in diverse environments. Cell shape in most bacteria is determined by the cell wall. A major challenge in this field has been deconvoluting the effects of differences in the chemical properties of the cell wall and the resulting cell shape perturbations on observed fitness changes. Still, such studies have begun to reveal the selective pressures that drive the diverse forms (or cell wall compositions) observed in mammalian pathogens and bacteria more generally, including efficient adherence to biotic and abiotic surfaces, survival under low-nutrient or stressful conditions, evasion of mammalian complement deposition, efficient dispersal through mucous barriers and tissues, and efficient nutrient acquisition.
Collapse
|
21
|
Minimal Peptidoglycan (PG) Turnover in Wild-Type and PG Hydrolase and Cell Division Mutants of Streptococcus pneumoniae D39 Growing Planktonically and in Host-Relevant Biofilms. J Bacteriol 2015; 197:3472-85. [PMID: 26303829 DOI: 10.1128/jb.00541-15] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 08/15/2015] [Indexed: 12/20/2022] Open
Abstract
UNLABELLED We determined whether there is turnover of the peptidoglycan (PG) cell wall of the ovococcus bacterial pathogen Streptococcus pneumoniae (pneumococcus). Pulse-chase experiments on serotype 2 strain D39 radiolabeled with N-acetylglucosamine revealed little turnover and release of PG breakdown products during growth compared to published reports of PG turnover in Bacillus subtilis. PG dynamics were visualized directly by long-pulse-chase-new-labeling experiments using two colors of fluorescent d-amino acid (FDAA) probes to microscopically detect regions of new PG synthesis. Consistent with minimal PG turnover, hemispherical regions of stable "old" PG persisted in D39 and TIGR4 (serotype 4) cells grown in rich brain heart infusion broth, in D39 cells grown in chemically defined medium containing glucose or galactose as the carbon source, and in D39 cells grown as biofilms on a layer of fixed human epithelial cells. In contrast, B. subtilis exhibited rapid sidewall PG turnover in similar FDAA-labeling experiments. High-performance liquid chromatography (HPLC) analysis of biochemically released peptides from S. pneumoniae PG validated that FDAAs incorporated at low levels into pentamer PG peptides and did not change the overall composition of PG peptides. PG dynamics were also visualized in mutants lacking PG hydrolases that mediate PG remodeling, cell separation, or autolysis and in cells lacking the MapZ and DivIVA division regulators. In all cases, hemispheres of stable old PG were maintained. In PG hydrolase mutants exhibiting aberrant division plane placement, FDAA labeling revealed patches of inert PG at turns and bulge points. We conclude that growing S. pneumoniae cells exhibit minimal PG turnover compared to the PG turnover in rod-shaped cells. IMPORTANCE PG cell walls are unique to eubacteria, and many bacterial species turn over and recycle their PG during growth, stress, colonization, and virulence. Consequently, PG breakdown products serve as signals for bacteria to induce antibiotic resistance and as activators of innate immune responses. S. pneumoniae is a commensal bacterium that colonizes the human nasopharynx and opportunistically causes serious respiratory and invasive diseases. The results presented here demonstrate a distinct demarcation between regions of old PG and regions of new PG synthesis and minimal turnover of PG in S. pneumoniae cells growing in culture or in host-relevant biofilms. These findings suggest that S. pneumoniae minimizes the release of PG breakdown products by turnover, which may contribute to evasion of the innate immune system.
Collapse
|
22
|
Evaluation of the Role of the opgGH Operon in Yersinia pseudotuberculosis and Its Deletion during the Emergence of Yersinia pestis. Infect Immun 2015; 83:3638-47. [PMID: 26150539 DOI: 10.1128/iai.00482-15] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 06/26/2015] [Indexed: 02/02/2023] Open
Abstract
The opgGH operon encodes glucosyltransferases that synthesize osmoregulated periplasmic glucans (OPGs) from UDP-glucose, using acyl carrier protein (ACP) as a cofactor. OPGs are required for motility, biofilm formation, and virulence in various bacteria. OpgH also sequesters FtsZ in order to regulate cell size according to nutrient availability. Yersinia pestis (the agent of flea-borne plague) lost the opgGH operon during its emergence from the enteropathogen Yersinia pseudotuberculosis. When expressed in OPG-negative strains of Escherichia coli and Dickeya dadantii, opgGH from Y. pseudotuberculosis restored OPGs synthesis, motility, and virulence. However, Y. pseudotuberculosis did not produce OPGs (i) under various growth conditions or (ii) when overexpressing its opgGH operon, its galUF operon (governing UDP-glucose), or the opgGH operon or Acp from E. coli. A ΔopgGH Y. pseudotuberculosis strain showed normal motility, biofilm formation, resistance to polymyxin and macrophages, and virulence but was smaller. Consistently, Y. pestis was smaller than Y. pseudotuberculosis when cultured at ≥ 37°C, except when the plague bacillus expressed opgGH. Y. pestis expressing opgGH grew normally in serum and within macrophages and was fully virulent in mice, suggesting that small cell size was not advantageous in the mammalian host. Lastly, Y. pestis expressing opgGH was able to infect Xenopsylla cheopis fleas normally. Our results suggest an evolutionary scenario whereby an ancestral Yersinia strain lost a factor required for OPG biosynthesis but kept opgGH (to regulate cell size). The opgGH operon was presumably then lost because OpgH-dependent cell size control became unnecessary.
Collapse
|
23
|
Jin L, Guo W, Xue P, Gao H, Zhao M, Zheng C, Zhang Y, Han D. Quantitative assay for the colonization ability of heterogeneous bacteria on controlled nanopillar structures. NANOTECHNOLOGY 2015; 26:055702. [PMID: 25581320 DOI: 10.1088/0957-4484/26/5/055702] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The colonization ability of bacteria on biomaterial surfaces is influenced by the morphology of the bacteria and the nanotopography of the biomaterial. However, interactions between the bacterial morphology and nanotopography of biomaterials have not yet been completely elucidated. In this article, we quantitatively characterized the bacterial morphology to illuminate the integrated effects of polyethylene terephthalate (PET) nanopillar arrays on the colonization of bacteria cells with different shapes. Our results demonstrated that the interaction between interpillar spacing and the diameter of the bacterial cells impacted the number of bacterial cells that adhered to different PET substrates. The interpillar spacing of nanopillar arrays promotes bacterial adhesion in a definite range (<50 nm). However, further increasing the interpillar spacing inhibited the adhesion of bacteria to the nanopillar arrays. Moreover, the interpillar spacing also influenced the morphologies of adherent bacterial cells on the PET nanopillar arrays, which consequently facilitated bacterial adhesion to the nanopillar arrays. Our findings enhance the understanding of interactions between controlled nanotopography and bacterial colonization and provide an appropriate parameter for the design of antibacterial materials with nanotopography.
Collapse
Affiliation(s)
- Lin Jin
- Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, People's Republic of China. National Center for Nanoscience and Technology, Beijing, People's Republic of China
| | | | | | | | | | | | | | | |
Collapse
|
24
|
Klein K, Palarasah Y, Kolmos HJ, Møller-Jensen J, Andersen TE. Quantification of filamentation by uropathogenic Escherichia coli during experimental bladder cell infection by using semi-automated image analysis. J Microbiol Methods 2014; 109:110-6. [PMID: 25546841 DOI: 10.1016/j.mimet.2014.12.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2014] [Revised: 12/08/2014] [Accepted: 12/23/2014] [Indexed: 01/03/2023]
Abstract
Several rod-shaped pathogens including Escherichia coli, Salmonella spp. and Klebsiella pneumonia are capable of adopting highly filamentous cell shapes under certain circumstances. This phenomenon occurs as a result of continued cell elongation during growth without the usual septation into single rod-shaped cells. Evidence has emerged over the past decade suggesting that this morphological transformation is controlled and reversible and provides selective advantages under certain growth conditions, such as during infection in humans. In order to identify the factors which induce filamentation of bacterial pathogens and study the advantages of bacterial morphological plasticity, methods are needed to accurately quantify changes in bacterial cell shape. In this study, we present a method for quantification of bacterial filamentation based on automatic detection and measurement of bacterial units in focus-stacked microscopy images. Used in combination with a flow-chamber based in vitro cystitis model, we study the factors involved in filament formation by uropathogenic E. coli (UPEC) during infection. The influence of substratum surface, intracellular proliferation and flow media on UPEC filamentation is evaluated. We show that reversible UPEC filamentation during cystitis is not dependent on intracellular infection, which previous studies have suggested. Instead, we find that filamentation can be induced by contact with surfaces, both biological and artificial. Lastly our data indicate that UPEC filamentation is induced by trace-amounts of specific components in urine, rather than being a generic stress-response to high urine salt concentrations. The study shows that the combined methodology is generally useful for investigation of bacterial morphological transitions during cell infection.
Collapse
Affiliation(s)
- Kasper Klein
- Research Unit of Clinical Microbiology, University of Southern Denmark, 5000 Odense C, Denmark
| | - Yaseelan Palarasah
- Research Unit of Immunology and Microbiology, University of Southern Denmark, 5000 Odense C, Denmark
| | - Hans Jørn Kolmos
- Research Unit of Clinical Microbiology, University of Southern Denmark, 5000 Odense C, Denmark
| | - Jakob Møller-Jensen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark
| | - Thomas Emil Andersen
- Research Unit of Clinical Microbiology, University of Southern Denmark, 5000 Odense C, Denmark
| |
Collapse
|
25
|
Mycobacterium abscessus cording prevents phagocytosis and promotes abscess formation. Proc Natl Acad Sci U S A 2014; 111:E943-52. [PMID: 24567393 DOI: 10.1073/pnas.1321390111] [Citation(s) in RCA: 235] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mycobacterium abscessus is a rapidly growing Mycobacterium causing a wide spectrum of clinical syndromes. It now is recognized as a pulmonary pathogen to which cystic fibrosis patients have a particular susceptibility. The M. abscessus rough (R) variant, devoid of cell-surface glycopeptidolipids (GPLs), causes more severe clinical disease than the smooth (S) variant, but the underlying mechanisms of R-variant virulence remain obscure. Exploiting the optical transparency of zebrafish embryos, we observed that the increased virulence of the M. abscessus R variant compared with the S variant correlated with the loss of GPL production. The virulence of the R variant involved the massive production of serpentine cords, absent during S-variant infection, and the cords initiated abscess formation leading to rapid larval death. Cording occurred within the vasculature and was highly pronounced in the central nervous system (CNS). It appears that M. abscessus is transported to the CNS within macrophages. The release of M. abscessus from apoptotic macrophages initiated the formation of cords that grew too large to be phagocytized by macrophages or neutrophils. This study is a description of the crucial role of cording in the in vivo physiopathology of M. abscessus infection and emphasizes cording as a mechanism of immune evasion.
Collapse
|