Role of SCFAs for Fimbrillin-Dependent Biofilm Formation of Actinomyces oris

Actinomyces oris expresses type 1 and 2 fimbriae on the cell surface. Type 2 fimbriae mediate co-aggregation and biofilm formation and are composed of the shaft fimbrillin FimA and the tip fimbrillin FimB. Short-chain fatty acids (SCFAs) are metabolic products of oral bacteria, but the effects of exogenous SCFAs on FimA-dependent biofilm formation are poorly understood. We performed two types of biofilm formation assays using A. oris MG1 or MG1.ΔfimA to observe the effects of SCFAs on FimA-dependent biofilm formation in 96-well and six-well microtiter plates and a flow cell system. SCFAs did not induce six- and 16-hour biofilm formation of A. oris MG1 and MG1.ΔfimA in saliva-coated 96-well and six-well microtiter plates in which metabolites produced during growth were not excluded. However, 6.25 mM butyric acid and 3.125 mM propionic acid induced FimA-dependent biofilm formation and cell death in a flow cell system in which metabolites produced during growth were excluded. Metabolites produced during growth may lead to disturbing effects of SCFAs on the biofilm formation. The pure effects of SCFAs on biofilm formation were induction of FimA-dependent biofilm formation, but the stress responses from dead cells may regulate its effects. Therefore, SCFA may play a key role in A. oris biofilm formation.

Download Full-text

Biofilm formation by Pseudomonas fluorescens WCS365: a role for LapD

Microbiology ◽

10.1099/mic.0.28696-0 ◽

2006 ◽

Vol 152 (5) ◽

pp. 1375-1383 ◽

Cited By ~ 76

Author(s):

Shannon M. Hinsa ◽

George A. O'Toole

Keyword(s):

Cell Surface ◽

Pseudomonas Fluorescens ◽

Outer Membrane ◽

Gene Product ◽

Biofilm Formation ◽

Flow Cell ◽

Cell System ◽

Inner Membrane ◽

Apparent Change

A role for the outer-membrane-associated LapA protein in early biofilm formation by Pseudomonas fluorescens WCS365 has previously been shown. This paper reports that lapD, a gene located adjacent to the lapA gene, also plays a role in biofilm formation. A mutation in lapD results in a conditional biofilm defect in a static assay – this biofilm phenotype is exacerbated when biofilm formation is assayed in a flow-cell system. Furthermore, a lapD mutation shows a partial defect in the transition from reversible to irreversible attachment, consistent with an early role for the lapD gene product in biofilm formation. LapD is shown to be localized to the inner membrane of P. fluorescens. The data show decreased LapA associated with the cell surface, but no apparent change in cytoplasmic levels of this protein or lapA transcription, in a lapD mutant. A model is proposed wherein the role of LapD in biofilm formation is modulating the secretion of the LapA adhesin.

Download Full-text

A universal stress protein in Mycobacterium smegmatis sequesters the cAMP-regulated lysine acyltransferase and is essential for biofilm formation

Journal of Biological Chemistry ◽

10.1074/jbc.ra119.011373 ◽

2019 ◽

Vol 295 (6) ◽

pp. 1500-1516 ◽

Cited By ~ 2

Author(s):

Sintu Samanta ◽

Priyanka Biswas ◽

Arka Banerjee ◽

Avipsa Bose ◽

Nida Siddiqui ◽

...

Keyword(s):

Stress Responses ◽

Mycobacterium Smegmatis ◽

Biofilm Formation ◽

Stress Proteins ◽

Response Regulator ◽

Stress Protein ◽

Colony Morphology ◽

Regulator Gene ◽

Its Gene

Universal stress proteins (USPs) are present in many bacteria, and their expression is enhanced under various environmental stresses. We have previously identified a USP in Mycobacterium smegmatis that is a product of the msmeg_4207 gene and is a substrate for a cAMP-regulated protein lysine acyltransferase (KATms; MSMEG_5458). Here, we explored the role of this USP (USP4207) in M. smegmatis and found that its gene is present in an operon that also contains genes predicted to encode a putative tripartite tricarboxylate transporter (TTT). Transcription of the TTT-usp4207 operon was induced in the presence of citrate and tartrate, perhaps by the activity of a divergent histidine kinase-response regulator gene pair. A usp4207-deleted strain had rough colony morphology and reduced biofilm formation compared with the WT strain; however, both normal colony morphology and biofilm formation were restored in a Δusp4207Δkatms strain. We identified several proteins whose acetylation was lost in the Δkatms strain, and whose transcript levels increased in M. smegmatis biofilms along with that of USP4207, suggesting that USP4207 insulates KATms from its other substrates in the cell. We propose that USP4207 sequesters KATms from diverse substrates whose activities are down-regulated by acylation but are required for biofilm formation, thus providing a defined role for this USP in mycobacterial physiology and stress responses.

Download Full-text

The Potential Role of a Corticotropin-Releasing Factor Receptor-1 Antagonist in Psychiatric Disorders

CNS Spectrums ◽

10.1017/s1092852900016709 ◽

2008 ◽

Vol 13 (6) ◽

pp. 467-483 ◽

Cited By ~ 13

Author(s):

Stephen M. Stahl ◽

Dana D. Wise

Keyword(s):

Stress Response ◽

Psychiatric Disorders ◽

Stress Responses ◽

Potential Role ◽

Corticotropin Releasing Factor ◽

Recovering Alcoholic ◽

Mood And Cognition ◽

Pituitary Adrenal Axis

The hypothalamic-pituitary-adrenal axis is a key mediator of the stress response in humans. The corticotropin-releasing factor (CRF) type 1 receptor (CRFR-1) in the pituitary gland is a gatekeeper for that response, and the CRFR-1 receptor is also present in many other mood- and cognition-related neural structures. Behaviorally, a number of relationships between stress and psychiatric disorders can be observed: chronic or repeated stress is associated with onset of depression; stressors can cause a recovering alcoholic to relapse; overactive stress responses mark many anxiety disorders; and insomnia can arise from an overactive stress response. Thus, a CRFR-1 antagonist could be useful for treating or preventing the consequences of CRF-mediated stress in depression, anxiety, insomnia, and substance abuse.

Download Full-text

Role of type 1 and type 3 fimbriae in Klebsiella pneumoniae biofilm formation

BMC Microbiology ◽

10.1186/1471-2180-10-179 ◽

2010 ◽

Vol 10 (1) ◽

pp. 179 ◽

Cited By ~ 85

Author(s):

Casper Schroll ◽

Kim B Barken ◽

Karen A Krogfelt ◽

Carsten Struve

Keyword(s):

Klebsiella Pneumoniae ◽

Biofilm Formation ◽

Type 3

Download Full-text

Biofilm Growth By Listeria Monocytogenes On Stainless Steel and Expression of Biofilm-Related Genes Under Stressing Conditions

10.21203/rs.3.rs-408423/v1 ◽

2021 ◽

Author(s):

Danilo Augusto Lopes da Silva ◽

Rafaela de Melo Tavares ◽

Anderson Carlos Camargo ◽

Ricardo Seiti Yamatogi ◽

Elaine Cristina Pereira De Martinis ◽

...

Keyword(s):

Stainless Steel ◽

Stress Responses ◽

Biofilm Formation ◽

Gene Networks ◽

Stop Codon ◽

Regulatory Gene ◽

Premature Stop Codon ◽

Biofilm Growth ◽

Adverse Conditions

Abstract This research was carried out to assess the ability of L. monocytogenes for adhesion and growth in biofilm on stainless steel coupons under different stressing conditions (NaCl, curing salts and quaternary ammonium compounds - QAC), besides determining the expression of different genes involved in biofilm formation and stress response. Results from crystal violet assay revealed that one isolate carrying a premature stop codon (PMSC) in agrC gene formed high-density biofilms in the presence of QAC or cure salts (7.5% and 10%). Reverse Transcriptase-qPCR results revealed that isolates of L. monocytogenes lineages I and II presented differences in transcriptional profile of genes related to biofilm formation and adaptation to environmental conditions. In conclusion, our results demonstrated how L. monocytogenes can survive, multiply and form biofilm under adverse conditions related to food processing environments. Differences in transcriptional expression were observed, highlighting the role of regulatory gene networks for particular serotypes under different stress responses.

Download Full-text

Type 1 Does the Two-Step: Type 1 Secretion Substrates with a Functional Periplasmic Intermediate

Journal of Bacteriology ◽

10.1128/jb.00168-18 ◽

2018 ◽

Vol 200 (18) ◽

Cited By ~ 18

Author(s):

T. Jarrod Smith ◽

Holger Sondermann ◽

George A. O'Toole

Keyword(s):

Biofilm Formation ◽

Cysteine Proteinase ◽

Secretion System ◽

Content Type ◽

Distinct Subgroup ◽

One Step ◽

Step Type ◽

Extracellular Environment

ABSTRACTBacteria have evolved several secretion strategies for polling and responding to environmental flux and insult. Of these, the type 1 secretion system (T1SS) is known to secrete an array of biologically diverse proteins—from small, <10-kDa bacteriocins to gigantic adhesins with a mass >1 MDa. For the last several decades, T1SSs have been characterized as a one-step translocation strategy whereby the secreted substrate is transported directly into the extracellular environment from the cytoplasm with no periplasmic intermediate. Recent phylogenetic, biochemical, and genetic evidences point to a distinct subgroup of T1SS machinery linked with a bacterial transglutaminase-like cysteine proteinase (BTLCP), which uses a two-step secretion mechanism. BTLCP-linked T1SSs transport a class of repeats-in-toxin (RTX) adhesins that are critical for biofilm formation. The prototype of this RTX adhesin group, LapA ofPseudomonas fluorescensPf0-1, uses a novel N-terminal retention module to anchor the adhesin at the cell surface as a secretion intermediate threaded through the outer membrane-localized TolC-like protein LapE. This secretion intermediate is posttranslationally cleaved by the BTLCP family LapG protein to release LapA from its cognate T1SS pore. Thus, the secretion of LapA and related RTX adhesins into the extracellular environment appears to be a T1SS-mediated two-step process that involves a periplasmic intermediate. In this review, we contrast the T1SS machinery and substrates of the BLTCP-linked two-step secretion process with those of the classical one-step T1SS to better understand the newly recognized and expanded role of this secretion machinery.

Download Full-text

Role of gut metabolism of adrenal corticosteroids and hypertension: clues gut-cleansing antibiotics give us

Physiological Genomics ◽

10.1152/physiolgenomics.00115.2018 ◽

2019 ◽

Vol 51 (3) ◽

pp. 83-89 ◽

Cited By ~ 6

Author(s):

David J. Morris ◽

Andrew S. Brem

Keyword(s):

Vascular Tissue ◽

Biological Effects ◽

Intestinal Bacteria ◽

Short Chain Fatty Acids ◽

Intestinal Microbiome ◽

Systemic Hypertension ◽

Hypertensive Animal ◽

Metabolic Products

Intestinal bacteria can metabolize sterols, bile acids, steroid hormones, dietary proteins, fiber, foodstuffs, and short chain fatty acids. The metabolic products generated by some of these intestinal bacteria have been linked to a number of systemic diseases including obesity with Type 2 diabetes mellitus, some forms of inflammation, and more recently, systemic hypertension. In this review, we primarily focus on the potential role selected gut bacteria play in metabolizing the endogenous glucocorticoids corticosterone and cortisol. Those generated steroid metabolites, when reabsorbed in the intestine back into the circulation, produce biological effects most notably as inhibitors of 11β-hydroxysteroid dehydrogenase (11β-HSD) types 1 and 2. Inhibition of the dehydrogenase actions of 11β-HSD, particularly in kidney and vascular tissue, allows both corticosterone and cortisol the ability to bind to and activate mineralocorticoid receptors with attended changes in sodium handling and vascular resistance leading to increases in blood pressure. In several animal models of hypertension, administration of gut-cleansing antibiotics results in transient resolution of hypertension and transfer of intestinal contents from a hypertensive animal to a normotensive animal produces hypertension in the recipient. Moreover, fecal samples from hypertensive humans transplanted into germ-free mice resulted in hypertension in the recipient mice. Thus, it appears that the intestinal microbiome may not just be an innocent bystander but certain perturbations in the type and number of bacteria may directly or indirectly affect hypertension and other diseases.

Download Full-text

Short chain fatty acids induced the type 1 and type 2 fimbrillin-dependent and fimbrillin-independent initial attachment and colonization of Actinomyces oris monoculture but not coculture with streptococci

BMC Microbiology ◽

10.1186/s12866-020-01976-4 ◽

2020 ◽

Vol 20 (1) ◽

Author(s):

Itaru Suzuki ◽

Takehiko Shimizu ◽

Hidenobu Senpuku

Keyword(s):

Fatty Acids ◽

Short Chain Fatty Acids ◽

Human Saliva ◽

Oral Bacteria ◽

Short Chain ◽

Tooth Surface ◽

Initial Attachment ◽

Chain Fatty Acids

Abstract Background Actinomyces oris is an early colonizer and has two types of fimbriae on its cell surface, type 1 fimbriae (FimP and FimQ) and type 2 fimbriae (FimA and FimB), which contribute to the attachment and coaggregation with other bacteria and the formation of biofilm on the tooth surface, respectively. Short-chain fatty acids (SCFAs) are metabolic products of oral bacteria including A. oris and regulate pH in dental plaques. To clarify the relationship between SCFAs and fimbrillins, effects of SCFAs on the initial attachment and colonization (INAC) assay using A. oris wild type and fimbriae mutants was investigated. INAC assays using A. oris MG1 strain cells were performed with SCFAs (acetic, butyric, propionic, valeric and lactic acids) or a mixture of them on human saliva-coated 6-well plates incubated in TSB with 0.25% sucrose for 1 h. The INAC was assessed by staining live and dead cells that were visualized with a confocal microscope. Results Among the SCFAs, acetic, butyric and propionic acids and a mixture of acetic, butyric and propionic acids induced the type 1 and type 2 fimbriae-dependent and independent INAC by live A. oris, but these cells did not interact with streptococci. The main effects might be dependent on the levels of the non-ionized acid forms of the SCFAs in acidic stress conditions. GroEL was also found to be a contributor to the FimA-independent INAC by live A. oris cells stimulated with non-ionized acid. Conclusion SCFAs affect the INAC-associated activities of the A. oris fimbrillins and non-fimbrillins during ionized and non-ionized acid formations in the form of co-culturing with other bacteria in the dental plaque but not impact the interaction of A. oris with streptococci.

Download Full-text

Gut Microbiota: FFAR Reaching Effects on Islets

Endocrinology ◽

10.1210/en.2018-00296 ◽

2018 ◽

Vol 159 (6) ◽

pp. 2495-2505 ◽

Cited By ~ 8

Author(s):

Medha Priyadarshini ◽

Guadalupe Navarro ◽

Brian T Layden

Keyword(s):

Fatty Acid ◽

Free Fatty Acid ◽

Gut Microbiota ◽

Metabolic Regulation ◽

Short Chain Fatty Acids ◽

Β Cells ◽

Fermentative Activity ◽

G Protein Coupled

Abstract The G protein–coupled receptors, free fatty acid (FFA) receptors 2 and 3 (FFA2 and FFA3), belonging to the free fatty acid receptor (FFAR) class, sense a distinct class of nutrients, short chain fatty acids (SCFAs). These receptors participate in both immune and metabolic regulation. The latter includes a role in regulating secretion of metabolic hormones. It was only recently that their role in pancreatic β cells was recognized; these receptors are known now to affect not only insulin secretion but also β-cell survival and proliferation. These observations make them excellent potential therapeutic targets in type 2 diabetes. Moreover, expression on both immune and β cells makes these receptors possible targets in type 1 diabetes. Furthermore, SCFAs are generated by gut microbial fermentative activity; therefore, signaling by FFA2 and FFA3 represents an exciting novel link between the gut microbiota and the β cells. This review enumerates the role of these receptors in β cells revealed so far and discusses possible roles in clinical translation.

Download Full-text