The Influence of Mucus Microstructure and Rheology in Helicobacter pylori Infection

Bansil, Rama; Celli, Jonathan P.; Hardcastle, Joseph; Turner, Bradley S.

doi:10.3389/fimmu.2013.00310

Cited by 115 publications

(113 citation statements)

References 110 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…To reach its niche, this bacterium must escape the highly acidic gastric lumen and traverse the gastric mucus layer. Gastric mucins display pH-and concentration-dependent viscoelastic properties, behaving as a viscoelastic gel at low pH or high mucin concentrations (Ͼ25 mg/ml) and as a viscoelastic solution at neutral pH and lower mucin concentrations (61)(62)(63)(64). It has been proposed that H. pylori utilizes the corkscrew model to penetrate and traverse the mucus gel to escape the acidic lumen, which is consistent with the motility defects observed for straight and curved mutants in soft agar.…”

Section: Corkscrews and Wavessupporting

confidence: 57%

Staying in Shape: the Impact of Cell Shape on Bacterial Survival in Diverse Environments

Yang

Blair

Salama

2016

Microbiol Mol Biol Rev

231

192

View full text Add to dashboard Cite

SUMMARYBacteria 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.

show abstract

Section: Corkscrews and Wavessupporting

confidence: 57%

Staying in Shape: the Impact of Cell Shape on Bacterial Survival in Diverse Environments

Yang

Blair

Salama

2016

Microbiol Mol Biol Rev

231

192

View full text Add to dashboard Cite

show abstract

“…It is known that the formation of gels in gastric mucin at low pH develops also unique rheological features (Bansil et al, 2013;Celli et al, 2007;2005). Gels are characterized by a viscoelastic response originated by the combined effect of both solid-like and liquid-like behavior.…”

Section: Introductionmentioning

confidence: 99%

“…Gelation of gastric mucus has been studied by several experimental techniques (Bansil et al, 2013;Hong et al, 2005). It has been concluded that conformational changes in mucin are developed as the pH is reduced to pH < 2.…”

Section: Introductionmentioning

confidence: 99%

Effect of pH on the rheological response of reconstituted gastric mucin

Caicedo¹,

Perilla²

2015

ing.inv.

View full text Add to dashboard Cite

The rheological response of reconstituted gastric mucin was studied by time dependent rheological experiments as function of pH. Mucin concentrations of 5 % and 10 % were prepared in buffer dispersions at pH of 1.15, 2.00, 2.55, 4.00 and 7.67. The isoelectric point was identified by z-potential between pH 2.00 to 2.55. Dynamic light scattering showed that as pH reduced, a second population of larger mucin aggregates was formed indicating the presence of new structures. Steady shear rheological measurements reflected the pseudoplastic behavior of mucin dispersions and the effect of concentration on viscosity. Creep-recovery measurements were performed on the regenerated mucus at different levels of pH. By creep, it was possible to determine the values of zero-shear-viscosity of mucin suspensions, with higher precision and in a lower experimental time than steady shear measurements. Additionally, it was found that at pH ∼1.15, the viscosity of the mucus increased to high values, which is an indicative of a gel-like structure. By recovery experiments, it was possible to find that even the very low viscosities the mucin suspensions at pH ∼1.15 possessed a defined elastic character. By the use of a four-element mechanistic viscoelastic model, it was concluded that this elasticity underwent retardation due to the combined effect of viscous and elastic responses.Keywords: Mucin, rheology, z-potential, creep, elasticity. RESUMENSe estudió la respuesta reológica de mucina gástrica reconstituida como función del pH mediante experimentos reológicos dependientes del tiempo. Se usaron concentraciones de mucina del 5 % y 10 % en soluciones buffer a valores de pH de 1.15, 2.00, 2.55, 4.00 y 7.67. Mediante potencial zeta se identifico que el punto isoeléctrico se ubicaba entre pH de 2.00 a 2.55. Los estudios de dispersión de luz dinámica mostraron que a mediada que el pH se reduce, una segunda población de agregados de mucina se forma, indicando el estructuramiento dentro del fluido. Las mediciones reológicas en estado estable, mostraron el comportamiento seudoplástico y el efecto de la concentración en las soluciones de mucina. Se llevaron a cabo determinaciones de fluencia lenta-recuperación sobre las suspensiones de mucina a diferentes valores de pH. Mediante fluencia lenta, se determinaron los valores de viscosidad a cero corte con mayor precisión y menor tiempo experimental que las mediciones de estado estable. Adicionalmente, se encontró que para pH ∼1.15 la viscosidad del mucus incrementó a valores altos, lo cual es una característica de las estructuras tipo gel. Los experimentos de recuperación mostraron que aun a bajas viscosidades las suspensiones de mucina a pH ∼1.15 poseían un carácter elástico definido. Mediante el uso de un modelo viscoelástico de cuatro elementos, se concluyó que esta elasticidad presentaba respuesta retardada debido al efecto combinado de los efectos viscoso y elástico.

show abstract

“…Defects in mucin production can lead to diseases such as ulcerative colitis when mucins are underproduced or cystic fibrosis and asthma when mucins are overproduced (4)(5)(6). In addition, studies have shown that mucins can interact with microbes, such as Helicobacter pylori, Haemophilus parainfluenzae, and human immunodeficiency virus (7)(8)(9)(10). These diseases and microbial interactions highlight the necessity of mucins as one of the body's key natural defenses; however, few studies have focused specifically on the connection between MUC5B salivary mucins and oral diseases.…”

mentioning

confidence: 99%

Salivary Mucins Protect Surfaces from Colonization by Cariogenic Bacteria

Frenkel

Ribbeck

2015

Appl Environ Microbiol

107

View full text Add to dashboard Cite

bUnderstanding how the body's natural defenses function to protect the oral cavity from the myriad of bacteria that colonize its surfaces is an ongoing topic of research that can lead to breakthroughs in treatment and prevention. One key defense mechanism on all moist epithelial linings, such as the mouth, gastrointestinal tract, and lungs, is a layer of thick, well-hydrated mucus. The main gel-forming components of mucus are mucins, large glycoproteins that play a key role in host defense. This study focuses on elucidating the connection between MUC5B salivary mucins and dental caries, one of the most common oral diseases. Dental caries is predominantly caused by Streptococcus mutans attachment and biofilm formation on the tooth surface. Once S. mutans attaches to the tooth, it produces organic acids as metabolic by-products that dissolve tooth enamel, leading to cavity formation. We utilize CFU counts and fluorescence microscopy to quantitatively show that S. mutans attachment and biofilm formation are most robust in the presence of sucrose and that aqueous solutions of purified human MUC5B protect surfaces by acting as an antibiofouling agent in the presence of sucrose. In addition, we find that MUC5B does not alter S. mutans growth and decreases surface attachment and biofilm formation by maintaining S. mutans in the planktonic form. These insights point to the importance of salivary mucins in oral health and lead to a better understanding of how MUC5B could play a role in cavity prevention or diagnosis. One of the body's key defense mechanisms on wet epithelial linings, such as the mouth, gastrointestinal tract, and lungs, is a layer of thick, well-hydrated mucus. The viscoelastic properties of mucus are attributed to mucins, large glycoproteins that play a key role in host defense and maintaining a healthy microbial environment (1-3). Defects in mucin production can lead to diseases such as ulcerative colitis when mucins are underproduced or cystic fibrosis and asthma when mucins are overproduced (4-6). In addition, studies have shown that mucins can interact with microbes, such as Helicobacter pylori, Haemophilus parainfluenzae, and human immunodeficiency virus (7-10). These diseases and microbial interactions highlight the necessity of mucins as one of the body's key natural defenses; however, few studies have focused specifically on the connection between MUC5B salivary mucins and oral diseases. This study fills this gap in understanding by exploring the connection between purified human MUC5B and the virulence of Streptococcus mutans, one of the main cavitycausing bacteria naturally found in the oral cavity (11). MUC7 is another salivary mucin, but MUC5B is the primary mucin component of the dental pellicle coating the soft and hard tissues in the oral cavity (12, 13). Importantly, the effects of MUC5B are characterized in a clinically relevant three-dimensional model that mimics the natural environment in the oral cavity; mucins are secreted into an aqueous phase as opposed to a two-dimensional surfac...

show abstract

The Influence of Mucus Microstructure and Rheology in Helicobacter pylori Infection

Cited by 115 publications

References 110 publications

Staying in Shape: the Impact of Cell Shape on Bacterial Survival in Diverse Environments

Staying in Shape: the Impact of Cell Shape on Bacterial Survival in Diverse Environments

Effect of pH on the rheological response of reconstituted gastric mucin

Salivary Mucins Protect Surfaces from Colonization by Cariogenic Bacteria

Contact Info

Product

Resources

About