scholarly journals Role of Sialic Acid inBrachyspira hyodysenteriaeAdhesion to Pig Colonic Mucins

2019 ◽  
Vol 87 (7) ◽  
Author(s):  
Macarena P. Quintana-Hayashi ◽  
Vignesh Venkatakrishnan ◽  
Freddy Haesebrouck ◽  
Sara Lindén
Keyword(s):  
Sialic Acid ◽  
Bacterial Growth ◽  
Mucus Layer ◽  
Mucin Secretion ◽  
Content Type ◽  
Brachyspira Hyodysenteriae ◽  
Intestinal Mucus ◽  
Bacterial Binding ◽  
Free Sialic Acid

ABSTRACTInfection withBrachyspira hyodysenteriaeresults in mucoid hemorrhagic diarrhea. This pathogen is associated with the colonic mucus layer, mainly composed of mucins. Infection regulates mucinO-glycosylation in the colon and increases mucin secretion as well asB. hyodysenteriaebinding sites on mucins. Here, we analyzed potential mucin epitopes forB. hyodysenteriaeadhesion in the colon, as well as the effect of colonic mucins on bacterial growth. Associations betweenB. hyodysenteriaebinding to pig colonic mucins and mucin glycan data showed thatB. hyodysenteriaebinding was associated with the presence ofN-glycolylneuraminic acid (NeuGc) on mucins. The role of sialic acid inB. hyodysenteriaeadhesion was analyzed after the removal of sialic acid residues on the mucins by enzymatic treatment with sialidase A, which decreased bacterial binding to the mucins. The effect of pig colonic mucins onB. hyodysenteriaegrowth was determined in carbohydrate-free medium.B. hyodysenteriaegrowth increased in the presence of mucins from two out of five infected pigs, suggesting utilization of mucins as a carbon source for growth. Additionally, bacterial growth was enhanced by free sialic acid andN-acetylglucosamine. The results highlight a role of sialic acid as an adhesion epitope forB. hyodysenteriaeinteraction with colonic mucins. Furthermore, the mucin response and glycosylation changes exerted in the colon duringB. hyodysenteriaeinfection result in a potentially favorable environment for pathogen growth in the intestinal mucus layer.

Brachyspira Species Avidity to Colonic Mucins from Pigs with and without Brachyspira hyodysenteriae Infection is Species-Specific and Varies between Strains

2021 ◽  
Author(s):  
Macarena P. Quintana-Hayashi ◽  
Mattias Erhardsson ◽  
Maxime Mahu ◽  
Vignesh Venkatakrishnan ◽  
Freddy Haesebrouck ◽  
...  
Keyword(s):  
Sialic Acid ◽  
Hierarchical Cluster ◽  
Swine Industry ◽  
Binding Ability ◽  
Orthogonal Projections ◽  
Brachyspira Hyodysenteriae ◽  
Projections To Latent Structures ◽  
Latent Structures ◽  
Species Specific

Brachyspira hyodysenteriae is commonly associated with swine dysentery (SD), a disease that has an economic impact in the swine industry. B. hyodysenteriae infection results in changes to the colonic mucus niche with a massive mucus induction, which substantially increases the amount of B. hyodysenteriae binding sites in the mucus. We have previously determined that a B. hyodysenteriae strain binds to colon mucins in a manner that differs between pigs and mucin types. Here, we investigated if adhesion to mucins is a trait observed across a broad set of B. hyodysenteriae strains and isolates and furthermore at a genus level ( B. innocens, B. pilosicoli, B. murdochii, B. hampsonii and B. intermedia strains). Our results show that binding to mucins appears to be specific to B. hyodysenteriae , and within this species, the binding ability to mucins varies between strains/isolates, increases to mucins from pigs with SD, and is associated to sialic acid epitopes on mucins. Infection with B. hyodysenteriae strain 8dII results in mucin glycosylation changes in the colon including a shift in sialic acid containing structures. Thus, we demonstrate through hierarchical cluster analysis and Orthogonal Projections to Latent Structures Discriminant Analysis (OPLS-DA) models of the relative abundances of sialic acid-containing glycans, that sialic acid containing structures in the mucin O -glycome are good predictors of B. hyodysenteriae strain 8dII infection in pigs. The results emphasize the role of sialic acids in governing B. hyodysenteriae interactions with its host, which may open perspectives for therapeutic strategies.

scholarly journals Role of Neuraminidase-Producing Bacteria in Exposing Cryptic Carbohydrate Receptors forStreptococcus gordoniiAdherence

2018 ◽  
Vol 86 (7) ◽  
pp. e00068-18 ◽  
Author(s):  
Alex Wong ◽  
Margaret A. Grau ◽  
Anirudh K. Singh ◽  
Shireen A. Woodiga ◽  
Samantha J. King
Keyword(s):  
Sialic Acid ◽  
Oral Cavity ◽  
Bacterial Species ◽  
Dependent Manner ◽  
Neuraminidase Treatment ◽  
Content Type ◽  
Oral Epithelial Cells ◽  
Oral Environment ◽  
Oral Epithelial

ABSTRACTStreptococcus gordoniiis an early colonizer of the oral cavity. Although a variety ofS. gordoniiadherence mechanisms have been described, current dogma is that the major receptor forS. gordoniiis sialic acid. However, as many bacterial species in the oral cavity produce neuraminidase that can cleave terminal sialic acid, it is unclear whetherS. gordoniirelies on sialic acid for adherence to oral surfaces or if this species has developed alternative binding strategies. Previous studies have examined adherence to immobilized glycoconjugates and identified binding to additional glycans, but no prior studies have defined the contribution of these different glycan structures in adherence to oral epithelial cells. We determined that the majority ofS. gordoniistrains tested did not rely on sialic acid for efficient adherence. In fact, adherence of some strains was significantly increased following neuraminidase treatment. Further investigation of representative strains that do not rely on sialic acid for adherence revealed binding not only to sialic acid via the serine-rich repeat protein GspB but also to β-1,4-linked galactose. Adherence to this carbohydrate occurs via an unknown adhesin distinct from those utilized byStreptococcus oralisandStreptococcus pneumoniae. Demonstrating the potential biological relevance of binding to this cryptic receptor, we established thatS. oralisincreasesS. gordoniiadherence in a neuraminidase-dependent manner. These data suggest thatS. gordoniihas evolved to simultaneously utilize both terminal and cryptic receptors in response to the production of neuraminidase by other species in the oral environment.

scholarly journals Bifidobacterium dentiumFortifies the Intestinal Mucus Layer via Autophagy and Calcium Signaling Pathways

mBio ◽  
2019 ◽  
Vol 10 (3) ◽  
Author(s):  
Melinda A. Engevik ◽  
Berkley Luk ◽  
Alexandra L. Chang-Graham ◽  
Anne Hall ◽  
Beatrice Herrmann ◽  
...  
Keyword(s):  
Calcium Signaling ◽  
Signaling Pathways ◽  
Goblet Cell ◽  
Cell Function ◽  
Goblet Cells ◽  
Mucus Layer ◽  
Content Type ◽  
Intestinal Mucus ◽  
Intestinal Mucus Layer

ABSTRACTMuch remains unknown about how the intestinal microbiome interfaces with the protective intestinal mucus layer.Bifidobacteriumspecies colonize the intestinal mucus layer and can modulate mucus production by goblet cells. However, selectBifidobacteriumstrains can also degrade protective glycans on mucin proteins. We hypothesized that the human-derived speciesBifidobacterium dentiumwould increase intestinal mucus synthesis and expulsion, without extensive degradation of mucin glycans.In silicodata revealed thatB. dentiumlacked the enzymes necessary to extensively degrade mucin glycans. This finding was confirmed by demonstrating thatB. dentiumcould not use naive mucin glycans as primary carbon sourcesin vitro. To examineB. dentiummucus modulationin vivo, Swiss Webster germfree mice were monoassociated with live or heat-killedB. dentium. LiveB. dentium-monoassociated mice exhibited increased colonic expression of goblet cell markersKrüppel-like factor 4(Klf4),Trefoil factor 3(Tff3),Relm-β,Muc2, and several glycosyltransferases compared to both heat-killedB. dentiumand germfree counterparts. Likewise, liveB. dentium-monoassociated colon had increased acidic mucin-filled goblet cells, as denoted by Periodic Acid-Schiff-Alcian Blue (PAS-AB) staining and MUC2 immunostaining.In vitro,B. dentium-secreted products, including acetate, were able to increase MUC2 levels in T84 cells. We also identified thatB. dentium-secreted products, such as γ-aminobutyric acid (GABA), stimulated autophagy-mediated calcium signaling and MUC2 release. This work illustrates thatB. dentiumis capable of enhancing the intestinal mucus layer and goblet cell function via upregulation of gene expression and autophagy signaling pathways, with a net increase in mucin production.IMPORTANCEMicrobe-host interactions in the intestine occur along the mucus-covered epithelium. In the gastrointestinal tract, mucus is composed of glycan-covered proteins, or mucins, which are secreted by goblet cells to form a protective gel-like structure above the epithelium. Low levels of mucin or alterations in mucin glycans are associated with inflammation and colitis in mice and humans. Although current literature links microbes to the modulation of goblet cells and mucins, the molecular pathways involved are not yet fully understood. Using a combination of gnotobiotic mice and mucus-secreting cell lines, we have identified a human-derived microbe,Bifidobacterium dentium, which adheres to intestinal mucus and secretes metabolites that upregulate the major mucin MUC2 and modulate goblet cell function. Unlike otherBifidobacteriumspecies,B. dentiumdoes not extensively degrade mucin glycans and cannot grow on mucin alone. This work points to the potential of usingB. dentiumand similar mucin-friendly microbes as therapeutic agents for intestinal disorders with disruptions in the mucus barrier.

scholarly journals A SimpleIn VitroGut Model for Studying the Interaction betweenEscherichia coliand the Intestinal Commensal Microbiota in Cecal Mucus

2018 ◽  
Vol 84 (24) ◽  
Author(s):  
Matthew E. Mokszycki ◽  
Mary Leatham-Jensen ◽  
Jon L. Steffensen ◽  
Ying Zhang ◽  
Karen A. Krogfelt ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Gene Profiling ◽  
Rrna Gene ◽  
Mucus Layer ◽  
Content Type ◽  
E Coli ◽  
Commensal Microbiota ◽  
Intestinal Mucus

ABSTRACTA novelin vitrogut model was developed to better understand the interactions betweenEscherichia coliand the mouse cecal mucus commensal microbiota. The gut model is simple and inexpensive while providing an environment that largely replicates the nonadherent mucus layer of the mouse cecum. 16S rRNA gene profiling of the cecal microbial communities of streptomycin-treated mice colonized withE. coliMG1655 orE. coliNissle 1917 and the gut model confirmed that the gut model properly reflected the community structure of the mouse intestine. Furthermore, the results from thein vitrogut model mimic the results of publishedin vivocompetitive colonization experiments. The gut model is initiated by the colonization of streptomycin-treated mice, and then the community is serially transferred in microcentrifuge tubes in an anaerobic environment generated in anaerobe jars. The nutritional makeup of the cecum is simulated in the gut model by using a medium consisting of porcine mucin, mouse cecal mucus, HEPES-Hanks buffer (pH 7.2), Cleland’s reagent, and agarose. Agarose was found to be essential for maintaining the stability of the microbial community in the gut model. The outcome of competitions betweenE. colistrains in thein vitrogut model is readily explained by the “restaurant hypothesis” of intestinal colonization. This simple model system potentially can be used to more fully understand how different members of the microbiota interact physically and metabolically during the colonization of the intestinal mucus layer.IMPORTANCEBoth commensal and pathogenic strains ofEscherichia coliappear to colonize the mammalian intestine by interacting physically and metabolically with other members of the microbiota in the mucus layer that overlays the cecal and colonic epithelium. However, the use of animal models and the complexity of the mammalian gut make it difficult to isolate experimental variables that might dictate the interactions betweenE. coliand other members of the microbiota, such as those that are critical for successful colonization. Here, we describe a simple and relatively inexpensivein vitrogut model that largely mimicsin vivoconditions and therefore can facilitate the manipulation of experimental variables for studying the interactions ofE. coliwith the intestinal microbiota.

scholarly journals Crucial Role of ppGpp in the Resilience of Escherichia coli to Growth Disruption

mSphere ◽  
2020 ◽  
Vol 5 (6) ◽  
pp. e01132-20
Author(s):  
Clément Patacq ◽  
Nicolas Chaudet ◽  
Fabien Létisse
Keyword(s):  
Escherichia Coli ◽  
Bacterial Growth ◽  
Crucial Role ◽  
Stringent Response ◽  
Content Type ◽  
E Coli ◽  
Changing Environments ◽  
Growth Recovery ◽  
Growth Disruption

ABSTRACTBacteria grow in constantly changing environments that can suddenly become completely depleted of essential nutrients. The stringent response, a rewiring of the cellular metabolism mediated by the alarmone (p)ppGpp, plays a crucial role in adjusting bacterial growth to the severity of the nutritional stress. The ability of (p)ppGpp to trigger a slowdown of cell growth or induce bacterial dormancy has been widely investigated. However, little is known about the role of (p)ppGpp in promoting growth recovery after severe growth inhibition. In this study, we performed a time-resolved analysis of (p)ppGpp metabolism in Escherichia coli as it recovered from a sudden slowdown in growth. The results show that E. coli recovers by itself from the growth disruption provoked by the addition of serine hydroxamate, the serine analogue that we used to induce the stringent response. Growth inhibition was accompanied by a severe disturbance of metabolic activity and, more surprisingly, a transient overflow of valine and alanine. Our data also show that ppGpp is crucial for growth recovery since in the absence of ppGpp, E. coli’s growth recovery was slower. In contrast, an increased concentration of pppGpp was found to have no significant effect on growth recovery. Interestingly, the observed decrease in intracellular ppGpp levels in the recovery phase correlated with bacterial growth, and the main effect involved in the return to the basal level was identified by flux calculation as growth dilution. This report thus significantly expands our knowledge of (p)ppGpp metabolism in E. coli physiology.IMPORTANCE The capacity of microbes to resist and overcome environmental insults, known as resilience, allows them to survive in changing environments but also to resist antibiotic and biocide treatments and immune system responses. Although the role of the stringent response in bacterial resilience to nutritional stresses has been well studied, little is known about its importance in the ability of the bacteria to not just resist but also recover from these disturbances. To address this important question, we investigated growth disruption resilience in the model bacterium Escherichia coli and its dependence on the stringent response alarmone (p)ppGpp by quantifying ppGpp and pppGpp levels as growth was disrupted and then recovered. Our findings may thus contribute to understanding how ppGpp improves E. coli’s resilience to nutritional stress and other environmental insults.

scholarly journals A7 THE ROLE OF PROTEASE-ACTIVATED RECEPTOR-2 IN GIARDIA INDUCED DISRUPTIONS OF THE INTESTINAL MUCUS LAYER

2018 ◽  
Vol 1 (suppl_2) ◽  
pp. 11-11
Author(s):  
E Fekete ◽  
C B Amat ◽  
T Allain ◽  
M Saiffeddine ◽  
M Hollenberg ◽  
...  
Keyword(s):  
Mucus Layer ◽  
Intestinal Mucus ◽  
Protease Activated Receptor 2 ◽  
Intestinal Mucus Layer

scholarly journals Virulence Traits of a Serogroup C Meningococcus and IsogeniccssAMutant, Defective in Surface-Exposed Sialic Acid, in a Murine Model of Meningitis

2019 ◽  
Vol 87 (4) ◽  
Author(s):  
Roberta Colicchio ◽  
Chiara Pagliuca ◽  
Susanna Ricci ◽  
Elena Scaglione ◽  
Denis Grandgirard ◽  
...  
Keyword(s):  
Sialic Acid ◽  
Corpus Callosum ◽  
Type Strain ◽  
Wild Type Strain ◽  
Lethal Dose ◽  
Sialic Acids ◽  
Wild Type ◽  
Knockout Mutant ◽  
Content Type

ABSTRACTIn serogroup CNeisseria meningitidis, thecssA(siaA) gene codes for an UDP-N-acetylglucosamine 2-epimerase that catalyzes the conversion of UDP-N-acetyl-α-d-glucosamine intoN-acetyl-d-mannosamine and UDP in the first step in sialic acid biosynthesis. This enzyme is required for the biosynthesis of the (α2→9)-linked polysialic acid capsule and for lipooligosaccharide (LOS) sialylation. In this study, we have used a reference serogroup C meningococcal strain and an isogeniccssAknockout mutant to investigate the pathogenetic role of surface-exposed sialic acids in a model of meningitis based on intracisternal inoculation of BALB/c mice. Results confirmed the key role of surface-exposed sialic acids in meningococcal pathogenesis. The 50% lethal dose (LD50) of the wild-type strain 93/4286 was about four orders of magnitude lower than that of thecssAmutant. Compared to the wild-type strain, the ability of this mutant to replicate in brain and spread systemically was severely impaired. Evaluation of brain damage evidenced a significant reduction in cerebral hemorrhages in mice infected with the mutant in comparison with the levels in those challenged with the wild-type strain. Histological analysis showed the typical features of bacterial meningitis, including inflammatory cells in the subarachnoid, perivascular, and ventricular spaces especially in animals infected with the wild type. Noticeably, 80% of mice infected with the wild-type strain presented with massive bacterial localization and accompanying inflammatory infiltrate in thecorpus callosum, indicating high tropism of meningococci exposing sialic acids toward this brain structure and a specific involvement of thecorpus callosumin the mouse model of meningococcal meningitis.

scholarly journals The Difference in the Mucus Organization Between the Small and Large Intestine and Its Protection of Selected Natural Substances. A Review

2018 ◽  
Vol 62 (4) ◽  
pp. 48-55
Author(s):  
R. Szabóová ◽  
Z. Faixová ◽  
Z. Maková ◽  
E. Piešová
Keyword(s):  
Goblet Cells ◽  
Mucus Layer ◽  
Mucus Production ◽  
Natural Substances ◽  
Intestinal Mucus ◽  
The Difference ◽  
Mucus Barrier ◽  
Microbial Toxins ◽  
Natural Additives

Abstract The mucus layer of the intestinal tract plays an important role of forming the front line of innate host defense. Recent studies have suggested that the involvement of feeding natural additives on protection/prevention/promotion of mucus production in the intestinal environment is beneficial. The goblet cells continually produce mucins for the retention of the mucus barrier under physiological conditions, but different factors (e. g. microorganisms, microbial toxins, viruses, cytokines, and enzymes) can have profound effects on the integrity of the intestinal epithelium covered by a protective mucus. The intestinal mucus forms enterocytes covered by transmembrane mucins and goblet cells produce by the secreted gel-forming mucins (MUC2). The mucus is organized in a single unattached mucus layer in the small intestine and in two mucus layers (inner, outer) in the colon. The main part of the review evaluates the effects of natural additives/substances supplementation to stimulate increased expression of MUC2 mucin in the intestine of animals.

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