Two rheologically different gastric mucus secretions with different putative functions

Taylor, C. R.

doi:10.1016/j.bbagen.2004.06.007

Cited by 30 publications

(35 citation statements)

References 24 publications

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“…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: 58%

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

Yang

Blair

Salama

2016

Microbiol Mol Biol Rev

231

192

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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.

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Section: Corkscrews and Wavessupporting

confidence: 58%

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

Yang

Blair

Salama

2016

Microbiol Mol Biol Rev

231

192

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“…Taylor et al (2004) have demonstrated two distinct mucus gel secretions in the stomach, an adherent and shear-resistant gel and a superficial shear-compliant gel; they speculate that the first one constitutes the mucus barrier and the other provides lubrication. The fact that the solMUC5B had a slightly higher density compared to the gelMUC5B fits nicely with the findings that the surface layer of stomach mucus displayed a lower density than the superficial layer.…”

Section: Discussionmentioning

confidence: 99%

“…the stomach and the respiratory tract) has been shown to be organized in layers, with one layer being more surfaceassociated and more 'insoluble', while a second layer is more porous (Taylor et al, 2004;Thornton & Sheehan, 2004;Sheehan et al, 2006;Hidaka et al, 2001). In the case of the stomach and the respiratory tract, different mucin gene products, MUC5AC and MUC6, MU5B and MUC5AC, respectively, may fulfil these two roles.…”

Section: Introductionmentioning

confidence: 99%

Differential metabolic activity by dental plaque bacteria in association with two preparations of MUC5B mucins in solution and in biofilms

2009

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Salivary mucin, MUC5B, is an oligomeric glycoprotein, heterogeneous in size and with a diverse repertoire of oligosaccharides, which differ in composition and charge. Since complex salivary glycoproteins are considered to be the major source of nutrients for the oral supragingival microbiota, the major aim of the current study was to determine whether different preparations of non-denatured MUC5B could be isolated exhibiting different biological properties in relation to the microflora associated with the surfaces of the oral cavity. Two preparations, solMUC5B and gelMUC5B, were isolated by density-gradient centrifugation and were shown to have different buoyant densities, carbohydrate content and surface-adsorbing characteristics. To ascertain differences in biological activity, the two mucin preparations, both in solution and adsorbed to a model surface, were incubated with freshly isolated dental plaque and assayed for metabolic (dehydrogenase) activity with the fluoresecent substrate CTC (5-cyano-2,3-ditolyl tetrazolium chloride). The plaque bacteria exhibited higher metabolism with the solMUC5B preparation in solution, with 79.4 % active plaque cells compared to the controls without mucin (9.6 %), while gelMUC5B showed 48.2 % active cells with the same plaque population. In contrast, the same mucins adhered to a surface elicited a significantly lower metabolic response, with surfaceassociated plaque cells showing only 12.1 % active cells with solMUC5B and 29.2 % with gelMUC5B. These results suggested that the metabolism by the plaque cells adsorbed to surface-associated mucins was downregulated compared to the same cells suspended in mucin solution. This was confirmed in an experiment where active dispersed plaque/solMUC5B suspensions were shown to lose significant metabolic activity (e.g. 74.9 to 19.3 %) when allowed to interact with gelMUC5B adsorbed to a surface. Clearly, the solMUC5B and gelMUC5B preparations exhibited different biological activity when assayed with freshly plaque bacteria in suspension and in a biofilm.

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“…Within the mouth, mucin is secreted alongside other salivary secretions and acts as a lubricant. In the stomach and intestine, mucus is secreted as a protective barrier [98].…”

Section: Fiber and Immune Functionmentioning

confidence: 99%

Dietary Fiber and Availability of Nutrients: A Case Study on Yoghurt as a Food Model

Staffolo¹,

Bevilacqua²,

Rodríguez³

et al. 2012

The Complex World of Polysaccharides

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Two rheologically different gastric mucus secretions with different putative functions

Cited by 30 publications

References 24 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

Differential metabolic activity by dental plaque bacteria in association with two preparations of MUC5B mucins in solution and in biofilms

Dietary Fiber and Availability of Nutrients: A Case Study on Yoghurt as a Food Model

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