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Liu X, Lertsethtakarn P, Mariscal VT, Yildiz F, Ottemann KM. Counterclockwise rotation of the flagellum promotes biofilm initiation in Helicobacter pylori. mBio 2024:e0044024. [PMID: 38700325 DOI: 10.1128/mbio.00440-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Accepted: 03/26/2024] [Indexed: 05/05/2024] Open
Abstract
Motility promotes biofilm initiation during the early steps of this process: microbial surface association and attachment. Motility is controlled in part by chemotaxis signaling, so it seems reasonable that chemotaxis may also affect biofilm formation. There is a gap, however, in our understanding of the interactions between chemotaxis and biofilm formation, partly because most studies analyzed the phenotype of only a single chemotaxis signaling mutant, e.g., cheA. Here, we addressed the role of chemotaxis in biofilm formation using a full set of chemotaxis signaling mutants in Helicobacter pylori, a class I carcinogen that infects more than half the world's population and forms biofilms. Using mutants that lack each chemotaxis signaling protein, we found that chemotaxis signaling affected the biofilm initiation stage, but not mature biofilm formation. Surprisingly, some chemotaxis mutants elevated biofilm initiation, while others inhibited it in a manner that was not tied to chemotaxis ability or ligand input. Instead, the biofilm phenotype correlated with flagellar rotational bias. Specifically, mutants with a counterclockwise bias promoted biofilm initiation, e.g., ∆cheA, ∆cheW, or ∆cheV1; in contrast, those with a clockwise bias inhibited it, e.g., ∆cheZ, ∆chePep, or ∆cheV3. We tested this correlation using a counterclockwise bias-locked flagellum, which induced biofilm formation independent of the chemotaxis system. These CCW flagella, however, were not sufficient to induce biofilm formation, suggesting there are downstream players. Overall, our work highlights the new finding that flagellar rotational direction promotes biofilm initiation, with the chemotaxis signaling system operating as one mechanism to control flagellar rotation. IMPORTANCE Chemotaxis signaling systems have been reported to contribute to biofilm formation in many bacteria; however, how they regulate biofilm formation remains largely unknown. Chemotaxis systems are composed of many distinct kinds of proteins, but most previous work analyzed the biofilm effect of loss of only a few. Here, we explored chemotaxis' role during biofilm formation in the human-associated pathogenic bacterium Helicobacter pylori. We found that chemotaxis proteins are involved in biofilm initiation in a manner that correlated with how they affected flagellar rotation. Biofilm initiation was high in mutants with counterclockwise (CCW) flagellar bias and low in those with clockwise bias. We supported the idea that a major driver of biofilm formation is flagellar rotational direction using a CCW-locked flagellar mutant, which stays CCW independent of chemotaxis input and showed elevated biofilm initiation. Our data suggest that CCW-rotating flagella, independent of chemotaxis inputs, are a biofilm-promoting signal.
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Affiliation(s)
- Xiaolin Liu
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, California, USA
| | - Paphavee Lertsethtakarn
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, California, USA
| | - Vanessa T Mariscal
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, California, USA
| | - Fitnat Yildiz
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, California, USA
| | - Karen M Ottemann
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, California, USA
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2
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Loewe B, Kozhukhov T, Shendruk TN. Anisotropic run-and-tumble-turn dynamics. SOFT MATTER 2024; 20:1133-1150. [PMID: 38226730 PMCID: PMC10828927 DOI: 10.1039/d3sm00589e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 12/12/2023] [Indexed: 01/17/2024]
Abstract
Run-and-tumble processes successfully model several living systems. While studies have typically focused on particles with isotropic tumbles, recent examples exhibit "tumble-turns", in which particles undergo 90° tumbles and so possess explicitly anisotropic dynamics. We study the consequences of such tumble-turn anisotropicity at both short and long-time scales. We model run-and-tumble-turn particles as self-propelled particles subjected to an angular potential that favors directions of movement parallel to Cartesian axes. Using agent-based simulations, we study the effects of the interplay between rotational diffusion and an aligning potential on the particles' trajectories, which leads to the right-angled turns. We demonstrate that the long-time effect is to alter the tumble-turn time, which governs the long-time dynamics. In particular, when normalized by this timescale, trajectories become independent of the underlying details of the potential. As such, we develop a simplified continuum theory, which quantitatively agrees with agent-based simulations. We find that the purely diffusive hydrodynamic limit still exhibits anisotropic features at intermediate times and conclude that the transition to diffusive dynamics precedes the transition to isotropic dynamics. By considering short-range repulsive and alignment particle-particle interactions, we show how the anisotropic features of a single particle are inherited by the global order of the system. We hope this work will shed light on how active systems can extend local anisotropic properties to macroscopic scales, which might be important in biological processes occurring in anisotropic environments.
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Affiliation(s)
- Benjamin Loewe
- SUPA, School of Physics and Astronomy, University of Edinburgh, Peter Guthrie Tait Road, Edinburgh EH9 3FD, UK.
| | - Timofey Kozhukhov
- SUPA, School of Physics and Astronomy, University of Edinburgh, Peter Guthrie Tait Road, Edinburgh EH9 3FD, UK.
| | - Tyler N Shendruk
- SUPA, School of Physics and Astronomy, University of Edinburgh, Peter Guthrie Tait Road, Edinburgh EH9 3FD, UK.
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3
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Su-Arcaro C, Liao W, Bieniek K, Constantino MA, Decker SM, Turner BS, Bansil R. Unraveling the Intertwined Effect of pH on Helicobacter pylori Motility and the Microrheology of the Mucin-Based Medium It Swims in. Microorganisms 2023; 11:2745. [PMID: 38004756 PMCID: PMC10673263 DOI: 10.3390/microorganisms11112745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 10/16/2023] [Accepted: 11/03/2023] [Indexed: 11/26/2023] Open
Abstract
The gastric pathogen, Helicobacter pylori bacteria have to swim across a pH gradient from 2 to 7 in the mucus layer to colonize the gastric epithelium. Previous studies from our group have shown that porcine gastric mucin (PGM) gels at an acidic pH < 4, and H. pylori bacteria are unable to swim in the gel, although their flagella rotate. Changing pH impacts both the rheological properties of gastric mucin and also influences the proton (H+)-pumped flagellar motors of H. pylori as well as their anti-pH sensing receptors. To unravel these intertwined effects of acidic pH on both the viscoelastic properties of the mucin-based mucus as well as the flagellar motors and chemo-receptors of the bacterium, we compared the motility of H. pylori in PGM with that in Brucella broth (BB10) at different pH values using phase contrast microscopy to track the motion of the bacteria. The results show that the distribution of swimming speeds and other characteristics of the bacteria trajectories exhibit pH-dependent differences in both media. The swimming speed exhibits a peak at pH 4 in BB10, and a less pronounced peak at a higher pH of 5 in PGM. At all pH values, the bacteria swam faster and had a longer net displacement in BB10 compared to PGM. While the bacteria were stuck in PGM gels at pH < 4, they swam at these acidic pH values in BB10, although with reduced speed. Decreasing pH leads to a decreased fraction of motile bacteria, with a decreased contribution of the faster swimmers to the distributions of speeds and net displacement of trajectories. The body rotation rate is weakly dependent on pH in BB10, whereas in PGM bacteria that are immobilized in the low pH gel are capable of mechano-sensing and rotate faster. Bacteria can be stuck in the gel in various ways, including the flagella getting entangled in the fibers of the gel or the cell body being stuck to the gel. Our results show that in BB10, swimming is optimized at pH4, reflecting the combined effects of pH sensing by anti-pH tactic receptors and impact on H+ pumping of flagellar motors, while the increase in viscosity of PGM with decreasing pH and gelation below pH 4 lead to further reduction in swimming speed, with optimal swimming at pH 5 and immobilization of bacteria below pH 4.
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Affiliation(s)
- Clover Su-Arcaro
- Department of Physics, Boston University, Boston, MA 02215, USA; (C.S.-A.); (W.L.); (K.B.); (M.A.C.); (S.M.D.)
| | - Wentian Liao
- Department of Physics, Boston University, Boston, MA 02215, USA; (C.S.-A.); (W.L.); (K.B.); (M.A.C.); (S.M.D.)
| | - Katarzyna Bieniek
- Department of Physics, Boston University, Boston, MA 02215, USA; (C.S.-A.); (W.L.); (K.B.); (M.A.C.); (S.M.D.)
| | - Maira A. Constantino
- Department of Physics, Boston University, Boston, MA 02215, USA; (C.S.-A.); (W.L.); (K.B.); (M.A.C.); (S.M.D.)
| | - Savannah M. Decker
- Department of Physics, Boston University, Boston, MA 02215, USA; (C.S.-A.); (W.L.); (K.B.); (M.A.C.); (S.M.D.)
| | - Bradley S. Turner
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA;
| | - Rama Bansil
- Department of Physics, Boston University, Boston, MA 02215, USA; (C.S.-A.); (W.L.); (K.B.); (M.A.C.); (S.M.D.)
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4
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Sun Q, Yuan C, Zhou S, Lu J, Zeng M, Cai X, Song H. Helicobacter pylori infection: a dynamic process from diagnosis to treatment. Front Cell Infect Microbiol 2023; 13:1257817. [PMID: 37928189 PMCID: PMC10621068 DOI: 10.3389/fcimb.2023.1257817] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 10/05/2023] [Indexed: 11/07/2023] Open
Abstract
Helicobacter pylori, a gram-negative microaerophilic pathogen, causes several upper gastrointestinal diseases, such as chronic gastritis, peptic ulcer disease, and gastric cancer. For the diseases listed above, H. pylori has different pathogenic mechanisms, including colonization and virulence factor expression. It is essential to make accurate diagnoses and provide patients with effective treatment to achieve positive clinical outcomes. Detection of H. pylori can be accomplished invasively and noninvasively, with both having advantages and limitations. To enhance therapeutic outcomes, novel therapeutic regimens, as well as adjunctive therapies with probiotics and traditional Chinese medicine, have been attempted along with traditional empiric treatments, such as triple and bismuth quadruple therapies. An H. pylori infection, however, is difficult to eradicate during treatment owing to bacterial resistance, and there is no commonly available preventive vaccine. The purpose of this review is to provide an overview of our understanding of H. pylori infections and to highlight current treatment and diagnostic options.
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Affiliation(s)
- Qifang Sun
- School of Traditional Chinese Medicine, Hunan University of Chinese Medicine, Changsha, Hunan, China
- Hunan Provincial Key Laboratory of Traditional Chinese Medicine (TCM) Diagnostics, Hunan University of Chinese Medicine, Changsha, Hunan, China
| | - Chengzhi Yuan
- Hunan Provincial Key Laboratory of Traditional Chinese Medicine (TCM) Diagnostics, Hunan University of Chinese Medicine, Changsha, Hunan, China
- School of Medicine, Hunan University of Chinese Medicine, Changsha, Hunan, China
| | - Sainan Zhou
- The First Hospital of Hunan University of Chinese Medicine, Changsha, Hunan, China
| | - Jing Lu
- School of Medicine, Hunan University of Chinese Medicine, Changsha, Hunan, China
| | - Meiyan Zeng
- School of Traditional Chinese Medicine, Hunan University of Chinese Medicine, Changsha, Hunan, China
| | - Xiong Cai
- School of International Education, Hunan University of Chinese Medicine, Changsha, Hunan, China
| | - Houpan Song
- School of Traditional Chinese Medicine, Hunan University of Chinese Medicine, Changsha, Hunan, China
- Hunan Provincial Key Laboratory of Traditional Chinese Medicine (TCM) Diagnostics, Hunan University of Chinese Medicine, Changsha, Hunan, China
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5
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Sagoo J, Abedrabbo S, Liu X, Ottemann KM. Discovery of Type IV filament membrane alignment complex homologs in H. pylori that promote soft-agar migration. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.27.537399. [PMID: 37163056 PMCID: PMC10168365 DOI: 10.1101/2023.04.27.537399] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The stomach pathogen Helicobacter pylori utilizes two scaffold proteins, CheW and CheV1, to build critical chemotaxis arrays. Chemotaxis helps bacteria establish and maintain infection. Mutants lacking either of these chemotaxis proteins have different soft agar phenotypes: deletion of cheW creates non-chemotactic strains, while deletion of cheV1 results in 50% loss of chemotaxis. In this work, we characterized the cheV1 deletion mutant phenotype in detail. cheV1 deletion mutants had poor soft-agar migration initially, but regained migration ability over time. This improved bacterial migration was stable, suggesting a genetic suppressor phenotype, termed Che+. Whole-genome sequencing analysis of four distinct cheV1 Che+ strains revealed single nucleotide polymorphisms (SNPs) in a common gene, HPG27_252 (HP0273). These SNPs were predicted to truncate the encoded protein. To confirm the role of HPG27_252 in the cheV1 phenotype, we created a targeted deletion of HPG27_252 and found that loss of HPG27_252 enhanced soft-agar migration. HPG27_252 and CheV1 appear to interact directly, based on bacterial two-hybrid analysis. HPG27_252 is predicted to encode a 179 amino acid, 21 kDa protein annotated as a hypothetical protein. Computational analysis revealed this protein to be a remote homolog of the PilO Type IV filament membrane alignment complex protein. Although H. pylori is not known to possess Type IV filaments, our analysis showed it retains an operon of genes for homologs of PilO, PilN, and PilM, but does not possess other Type IV pili genes. Our data suggest the PilO homolog plays a role in regulating H. pylori chemotaxis and motility, suggesting new ideas about evolutionary steps for controlling migration through semi-solid media.
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6
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Bansil R, Constantino MA, Su-Arcaro C, Liao W, Shen Z, Fox JG. Motility of Different Gastric Helicobacter spp. Microorganisms 2023; 11:634. [PMID: 36985208 PMCID: PMC10058440 DOI: 10.3390/microorganisms11030634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 02/24/2023] [Accepted: 02/28/2023] [Indexed: 03/06/2023] Open
Abstract
Helicobacter spp., including the well-known human gastric pathogen H. pylori, can cause gastric diseases in humans and other mammals. They are Gram-negative bacteria that colonize the gastric epithelium and use their multiple flagella to move across the protective gastric mucus layer. The flagella of different Helicobacter spp. vary in their location and number. This review focuses on the swimming characteristics of different species with different flagellar architectures and cell shapes. All Helicobacter spp. use a run-reverse-reorient mechanism to swim in aqueous solutions, as well as in gastric mucin. Comparisons of different strains and mutants of H. pylori varying in cell shape and the number of flagella show that their swimming speed increases with an increasing number of flagella and is somewhat enhanced with a helical cell body shape. The swimming mechanism of H. suis, which has bipolar flagella, is more complex than that of unipolar H. pylori. H. suis exhibits multiple modes of flagellar orientation while swimming. The pH-dependent viscosity and gelation of gastric mucin significantly impact the motility of Helicobacter spp. In the absence of urea, these bacteria do not swim in mucin gel at pH < 4, even though their flagellar bundle rotates.
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Affiliation(s)
- Rama Bansil
- Department of Physics, Boston University, Boston, MA 02215, USA
| | | | | | - Wentian Liao
- Department of Physics, Boston University, Boston, MA 02215, USA
| | - Zeli Shen
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02138, USA
| | - James G. Fox
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02138, USA
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7
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Gupta R, Yuan J, Lele PP. Bacterial Proprioception: Can a Bacterium Sense Its Movement? Front Microbiol 2022; 13:928408. [PMID: 35875555 PMCID: PMC9302961 DOI: 10.3389/fmicb.2022.928408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 06/16/2022] [Indexed: 11/13/2022] Open
Abstract
The evolution of the bacterial flagellum gave rise to motility and repurposing of a signaling network, now termed the chemotaxis network, enabled biasing of cell movements. This made it possible for the bacterium to seek out favorable chemical environments. To enable chemotaxis, the chemotaxis network sensitively detects extracellular chemical stimuli and appropriately modulates flagellar functions. Additionally, the flagellar motor itself is capable of detecting mechanical stimuli and adapts its structure and function in response, likely triggering a transition from planktonic to surface-associated lifestyles. Recent work has shown a link between the flagellar motor's response to mechanical stimuli and the chemotactic output. Here, we elaborate on this link and discuss how it likely helps the cell sense and adapt to changes in its swimming speeds in different environments. We discuss the mechanism whereby the motor precisely tunes its chemotaxis output under different mechanical loads, analogous to proprioception in higher order organisms. We speculate on the roles bacterial proprioception might play in a variety of phenomena including the transition to surface-associated lifestyles such as swarming and biofilms.
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Affiliation(s)
- Rachit Gupta
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX, United States
| | - Junhua Yuan
- Department of Physics, University of Science and Technology of China, Hefei, China
| | - Pushkar P Lele
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX, United States
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8
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Lynch JB, James N, McFall-Ngai M, Ruby EG, Shin S, Takagi D. Transitioning to confined spaces impacts bacterial swimming and escape response. Biophys J 2022; 121:2653-2662. [PMID: 35398019 PMCID: PMC9300662 DOI: 10.1016/j.bpj.2022.04.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 12/28/2021] [Accepted: 04/05/2022] [Indexed: 11/02/2022] Open
Abstract
Symbiotic bacteria often navigate complex environments before colonizing privileged sites in their host organism. Chemical gradients are known to facilitate directional taxis of these bacteria, guiding them toward their eventual destination. However, less is known about the role of physical features in shaping the path the bacteria take and defining how they traverse a given space. The flagellated marine bacterium Vibrio fischeri, which forms a binary symbiosis with the Hawaiian bobtail squid, Euprymna scolopes, must navigate tight physical confinement during colonization, squeezing through a tissue bottleneck constricting to ∼2 μm in width on the way to its eventual home. Using microfluidic in vitro experiments, we discovered that V. fischeri cells alter their behavior upon entry into confined space, straightening their swimming paths and promoting escape from confinement. Using a computational model, we attributed this escape response to two factors: reduced directional fluctuation and a refractory period between reversals. Additional experiments in asymmetric capillary tubes confirmed that V. fischeri quickly escape from confined ends, even when drawn into the ends by chemoattraction. This avoidance was apparent down to a limit of confinement approaching the diameter of the cell itself, resulting in a balance between chemoattraction and evasion of physical confinement. Our findings demonstrate that nontrivial distributions of swimming bacteria can emerge from simple physical gradients in the level of confinement. Tight spaces may serve as an additional, crucial cue for bacteria while they navigate complex environments to enter specific habitats.
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Affiliation(s)
- Jonathan B Lynch
- Pacific Biosciences Research Center, University of Hawai'i at Mānoa, Honolulu, Hawai'i.
| | - Nicholas James
- Department of Cell and Molecular Biology, University of Hawai'i at Mānoa, Honolulu, Hawai'i
| | - Margaret McFall-Ngai
- Pacific Biosciences Research Center, University of Hawai'i at Mānoa, Honolulu, Hawai'i
| | - Edward G Ruby
- Pacific Biosciences Research Center, University of Hawai'i at Mānoa, Honolulu, Hawai'i
| | - Sangwoo Shin
- Department of Mechanical Engineering, University of Hawai'i at Mānoa, Honolulu, Hawai'i; Department of Mechanical and Aerospace Engineering, University at Buffalo, Buffalo, New York
| | - Daisuke Takagi
- Pacific Biosciences Research Center, University of Hawai'i at Mānoa, Honolulu, Hawai'i; Department of Mechanical Engineering, University of Hawai'i at Mānoa, Honolulu, Hawai'i; Department of Mathematics, University of Hawai'i at Mānoa, Honolulu, Hawai'i
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9
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Abstract
A huge number of bacterial species are motile by flagella, which allow them to actively move toward favorable environments and away from hazardous areas and to conquer new habitats. The general perception of flagellum-mediated movement and chemotaxis is dominated by the Escherichia coli paradigm, with its peritrichous flagellation and its famous run-and-tumble navigation pattern, which has shaped the view on how bacteria swim and navigate in chemical gradients. However, a significant amount-more likely the majority-of bacterial species exhibit a (bi)polar flagellar localization pattern instead of lateral flagella. Accordingly, these species have evolved very different mechanisms for navigation and chemotaxis. Here, we review the earlier and recent findings on the various modes of motility mediated by polar flagella. Expected final online publication date for the Annual Review of Microbiology, Volume 76 is September 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Kai M Thormann
- Institute of Microbiology and Molecular Biology, Justus Liebig University Gießen, Gießen, Germany;
| | - Carsten Beta
- Institute of Physics and Astronomy, University of Potsdam, Potsdam, Germany;
| | - Marco J Kühn
- Institute of Bioengineering and Global Health Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland;
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10
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Schwanbeck J, Oehmig I, Groß U, Zautner AE, Bohne W. Clostridioides difficile Single Cell Swimming Strategy: A Novel Motility Pattern Regulated by Viscoelastic Properties of the Environment. Front Microbiol 2021; 12:715220. [PMID: 34367119 PMCID: PMC8333305 DOI: 10.3389/fmicb.2021.715220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 06/29/2021] [Indexed: 11/22/2022] Open
Abstract
Flagellar motility is important for the pathogenesis of many intestinal pathogens, allowing bacteria to move to their preferred ecological niche. Clostridioides difficile is currently the major cause for bacterial health care-associated intestinal infections in the western world. Most clinical strains produce peritrichous flagella and are motile in soft-agar. However, little knowledge exists on the C. difficile swimming behaviour and its regulation at the level of individual cells. We report here on the swimming strategy of C. difficile at the single cell level and its dependency on environmental parameters. A comprehensive analysis of motility parameters from several thousand bacteria was achieved with the aid of a recently developed bacterial tracking programme. C. difficile motility was found to be strongly dependent on the matrix elasticity of the medium. Long run phases of all four motile C. difficile clades were only observed in the presence of high molecular weight molecules such as polyvinylpyrrolidone (PVP) and mucin, which suggests an adaptation of the motility apparatus to the mucin-rich intestinal environment. Increasing mucin or PVP concentrations lead to longer and straighter runs with increased travelled distance per run and fewer turnarounds that result in a higher net displacement of the bacteria. The observed C. difficile swimming pattern under these conditions is characterised by bidirectional, alternating back and forth run phases, interrupted by a short stop without an apparent reorientation or tumbling phase. This motility type was not described before for peritrichous bacteria and is more similar to some previously described polar monotrichous bacteria.
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Affiliation(s)
- Julian Schwanbeck
- Institute for Medical Microbiology and Virology, University Medical Center Göttingen, Göttingen, Germany
| | - Ines Oehmig
- Institute for Medical Microbiology and Virology, University Medical Center Göttingen, Göttingen, Germany
| | - Uwe Groß
- Institute for Medical Microbiology and Virology, University Medical Center Göttingen, Göttingen, Germany
| | - Andreas E Zautner
- Institute for Medical Microbiology and Virology, University Medical Center Göttingen, Göttingen, Germany
| | - Wolfgang Bohne
- Institute for Medical Microbiology and Virology, University Medical Center Göttingen, Göttingen, Germany
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