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Oral bacteria signal transduction

Pratick Khara, Saswat Sourav Mohapatra, Indranil Biswas
Streptococcus mutans, the primary aetiological agent of dental caries, is one of the major bacteria of the human oral cavity. The pathogenicity of this bacterium is attributed not only to the expression of virulence factors, but also to its ability to respond and adapt rapidly to the ever-changing conditions of the oral cavity. The two-component signal transduction system (TCS) CovR/S plays a crucial role in virulence and stress response in many streptococci. Surprisingly, in S. mutans the response regulator CovR appears to be an orphan, as the cognate sensor kinase, CovS, is absent in all the strains...
April 2018: Microbiology
Renata O Mattos-Graner, Margaret J Duncan
We present an overview of how members of the oral microbiota respond to their environment by regulating gene expression through two-component signal transduction systems (TCSs) to support conditions compatible with homeostasis in oral biofilms or drive the equilibrium toward dysbiosis in response to environmental changes. Using studies on the sub-gingival Gram-negative anaerobe Porphyromonas gingivalis and Gram-positive streptococci as examples, we focus on the molecular mechanisms involved in activation of TCS and species specificities of TCS regulons...
2017: Journal of Oral Microbiology
Abbas Asoudeh-Fard, Abolfazl Barzegari, Alireza Dehnad, Sepideh Bastani, Asal Golchin, Yadollah Omidi
Introduction: The oral tumor is the sixth most prevalent type of cancer worldwide and the second leading cause of cancer-related mortality. Although chemotherapy and immunotherapy are the main strategies for the treatment of oral cancer, an emergence of inevitable resistance to these treatment modalities is the major drawback that causes recurrence of the disease. Nowadays, probiotics have been suggested as adjunctive and complementary treatment modalities for improving the impacts of chemotherapy and immunotherapy agents...
2017: BioImpacts: BI
Raavi, Swechha Mishra, Sangeeta Singh
In P.aeruginosa biofilms, the issue of antibiotic resistance is of particular importance due to increasing number of infections being reported in medical implants. The current study is focused on CzcR and CopR proteins which are part of two-component signal transduction systems (TCSs) - CzcR-CzcS and CopR-CopS respectively in P.aeruginosa. They both negatively regulate OprD porin expression which affects the intake of antibiotics like carbapenems. These two proteins can be treated as targets to combat antibiotic resistance in P...
August 19, 2017: Microbial Pathogenesis
Miki Kawada-Matsuo, Hitoshi Komatsuzawa
Approximately 100 trillion microorganisms exist in the oral cavity. For the commensal bacteria of the oral cavity, it is important to adapt to environmental stimuli, including human- or bacteria-derived antimicrobial agents. Recently, bacterial-specific signal transduction regulatory systems, called two-component systems (TCSs), which appear to be focused on sensing and adapting to the environment, were discovered. Streptococcus mutans is an oral commensal bacteria and is also known as a cariogenic bacteria...
August 2017: Japanese Dental Science Review
Kristin Jacob, Anna Rasmussen, Paul Tyler, Mariah M Servos, Mariame Sylla, Cecilia Prado, Elizabeth Daniele, Josh S Sharp, Alexandra E Purdy
The CrbS/R two-component signal transduction system is a conserved regulatory mechanism through which specific Gram-negative bacteria control acetate flux into primary metabolic pathways. CrbS/R governs expression of acetyl-CoA synthase (acsA), an enzyme that converts acetate to acetyl-CoA, a metabolite at the nexus of the cell's most important energy-harvesting and biosynthetic reactions. During infection, bacteria can utilize this system to hijack host acetate metabolism and alter the course of colonization and pathogenesis...
2017: PloS One
R Doug Wagner, Shemedia J Johnson
BACKGROUND: Salmonella enterica infections often exhibit a form of immune evasion. We previously observed that probiotic bacteria could prevent inhibition of lymphoproliferation and apoptosis responses of T cells associated with S. enterica infections in orally challenged mice. RESULTS: In this study, changes in expression of genes related to lymphocyte activation in mucosa-associated lymphoid tissues (MALT) of mice orally infected with S. enterica with and without treatment with probiotic bacteria were evaluated...
March 29, 2017: BMC Microbiology
Ji-Woong Choi, Tae-Yub Kwon, Su-Hyung Hong, Heon-Jin Lee
MicroRNAs in eukaryotic cells are thought to control highly complex signal transduction and other biological processes by regulating coding transcripts, accounting for their important role in cellular events in eukaryotes. Recently, a novel class of bacterial RNAs similar in size [18-22 nucleotides (nt)] to microRNAs has been reported. Herein, we describe microRNAs, small RNAs from the oral pathogen Streptococcus sanguinis. The bacteria are normally present in the oral cavities and cause endocarditis by contaminating bloodstreams...
June 2018: Cell Biochemistry and Biophysics
B A Herbert, C M Novince, K L Kirkwood
Aggregatibacter actinomycetemcomitans is a perio-pathogenic bacteria that has long been associated with localized aggressive periodontitis. The mechanisms of its pathogenicity have been studied in humans and preclinical experimental models. Although different serotypes of A. actinomycetemcomitans have differential virulence factor expression, A. actinomycetemcomitans cytolethal distending toxin (CDT), leukotoxin, and lipopolysaccharide (LPS) have been most extensively studied in the context of modulating the host immune response...
June 2016: Molecular Oral Microbiology
Elaine M Haase, Xianghui Feng, Jiachuan Pan, Jeffrey C Miecznikowski, Frank A Scannapieco
Streptococcus gordonii, a primary colonizer of the tooth surface, interacts with salivary α-amylase via amylase-binding protein A (AbpA). This enzyme hydrolyzes starch to glucose, maltose, and maltodextrins that can be utilized by various oral bacteria for nutrition. Microarray studies demonstrated that AbpA modulates gene expression in response to amylase, suggesting that the amylase-streptococcal interaction may function in ways other than nutrition. The goal of this study was to explore the role of AbpA in gene regulation through comparative transcriptional profiling of wild-type KS1 and AbpA(-) mutant KS1ΩabpA under various environmental conditions...
August 15, 2015: Applied and Environmental Microbiology
Silvia Stockinger, Claudia U Duerr, Marcus Fulde, Tamas Dolowschiak, Johanna Pott, Ines Yang, Daniel Eibach, Fredrik Bäckhed, Shizuo Akira, Sebastian Suerbaum, Martijn Brugman, Mathias W Hornef
Recent results indicate a significant contribution of innate immune signaling to maintain mucosal homeostasis, but the precise underlying signal transduction pathways are ill-defined. By comparative analysis of intestinal epithelial cells isolated from conventionally raised and germ-free mice, as well as animals deficient in the adaptor molecules MyD88 and TRIF, the TLR3 and TLR4, as well as the type I and III IFN receptors, we demonstrate significant TLR-mediated signaling under homeostatic conditions. Surprisingly, homeostatic expression of Reg3γ and Paneth cell enteric antimicrobial peptides critically relied on TRIF and, in part, TLR3 but was independent of IFN receptor signaling...
October 15, 2014: Journal of Immunology: Official Journal of the American Association of Immunologists
Dipanwita Sengupta, Dae-Joong Kang, Cecilia Anaya-Bergman, Tiana Wyant, Arnab K Ghosh, Hiroshi Miyazaki, Janina P Lewis
Prevotella intermedia is an oral bacterium implicated in a variety of oral diseases. Although internalization of this bacterium by nonphagocytic host cells is well established, the molecular players mediating the process are not well known. Here, the properties of a leucine-rich repeat (LRR) domain protein, designated AdpF, are described. This protein contains a leucine-rich region composed of 663 amino acid residues, and molecular modeling shows that it folds into a classical curved solenoid structure. The cell surface localization of recombinant AdpF (rAdpF) was confirmed by electron and confocal microscopy analyses...
June 2014: Infection and Immunity
Matthew L Williams, Paula J Crowley, Adnan Hasona, L Jeannine Brady
Streptococcus mutans is a cariogenic oral pathogen whose virulence is determined largely by its membrane composition. The signal recognition particle (SRP) protein-targeting pathway plays a pivotal role in membrane biogenesis. S. mutans SRP pathway mutants demonstrate growth defects, cannot contend with environmental stress, and exhibit multiple changes in membrane composition. This study sought to define a role for ylxM, which in S. mutans and numerous other bacteria resides directly upstream of the ffh gene, encoding a major functional element of the bacterial SRP...
June 2014: Journal of Bacteriology
Nicholas S Jakubovics, Sufian A Yassin, Alexander H Rickard
It is now clear that the most common oral diseases, dental caries and periodontitis, are caused by mixed-species communities rather than by individual pathogens working in isolation. Oral streptococci are central to these disease processes since they are frequently the first microorganisms to colonize oral surfaces and they are numerically the dominant microorganisms in the human mouth. Numerous interactions between oral streptococci and other bacteria have been documented. These are thought to be critical for the development of mixed-species oral microbial communities and for the transition from oral health to disease...
2014: Advances in Applied Microbiology
Teresa Schaumann, Dominik Kraus, Jochen Winter, Michael Wolf, James Deschner, Andreas Jäger
Gingival epithelial cells (GECs) represent a physical barrier against bacteria and are involved in the processes of innate immunity. Recently, an anti-inflammatory and immune-modulatory effect of the amino acid glycine has been demonstrated. However, there is only little information about the immune-modulatory effects of glycine in oral tissues. This study aimed to investigate the existence and role of the glycine receptor in gingival tissue analyzing tissues/cells from extracted human molars via immunohistochemical analysis...
2013: Clinical & Developmental Immunology
Sun Woong Hong, Jung Eun Baik, Seok-Seong Kang, Cheol-Heui Yun, Deog-Gyu Seo, Seung Hyun Han
Streptococcus mutans is a pathogenic Gram-positive bacterium that is closely associated with dental caries and subsequent pulpal inflammation. Although lipoteichoic acid (LTA) is considered a major virulence factor of Gram-positive bacteria, little is known about the innate immunity to S. mutans LTA. In this study, we purified LTA from S. mutans (Sm.LTA) through n-butanol extraction, hydrophobic interaction column chromatography, and ion-exchange column chromatography to investigate its immunological properties using murine macrophages...
February 2014: Molecular Immunology
Qian Li, Chunling Pan, Di Teng, Li Lin, Yurong Kou, Elaine M Haase, Frank A Scannapieco, Yaping Pan
Pseudomonas aeruginosa is an important opportunistic bacterial pathogen, causing infections of respiratory and other organ systems in immunocompromised hosts that may invade and proliferate in mucosal epithelial cells to induce apoptosis. Previous studies suggest that oral bacteria, especially gram-negative periodontal pathogens, may enhance P. aeruginosa invasion into respiratory epithelial cells to augment tissue destruction. In this study, we investigated the effect of the periodontopathogen Porphyromonas gingivalis on P...
January 2014: Microbes and Infection
Srinivas R Myneni, Rajendra P Settem, Ashu Sharma
Bone undergoes a continuous cycle of remodeling for maintenance and healing. For almost a decade it has been appreciated that the immune system is intricately linked to bone homeostasis. Both acute and chronic inflammatory responses have been shown to impact bone health. A common form of inflammatory disease that causes bone destruction is the chronic infectious disease known as periodontitis (PD). PD is a bacteria-driven inflammation of the tooth-supporting apparatus that leads to resorption of the alveolar (jaw) bone, often leading to tooth loss...
2013: Immunological Investigations
Dominique S Michaud
Established risk factors for pancreatic cancer, including tobacco smoking, chronic pancreatitis, obesity and type 2 diabetes, collectively account for less than half of all pancreatic cancer cases. Inflammation plays a key role in pancreatic carcinogenesis, but it is unclear what causes local inflammation, other than pancreatitis. Epidemiological data suggest that Helicobacter pylori may be a risk factor for pancreatic cancer, and more recently, data suggest that periodontal disease, and Porphyromonas gingivalis, a pathogen for periodontal disease, may also play a role in pancreatic carcinogenesis...
October 2013: Carcinogenesis
Yizu Jiao, Youssef Darzi, Kazuki Tawaratsumida, Julie T Marchesan, Mizuho Hasegawa, Henry Moon, Grace Y Chen, Gabriel Núñez, William V Giannobile, Jeroen Raes, Naohiro Inohara
Periodontitis is a common disease that is characterized by resorption of the alveolar bone and mediated by commensal bacteria that trigger host immune responses and bone destruction through unidentified mechanisms. We report that Nod1, an innate intracellular host receptor for bacterial peptidoglycan-related molecules, is critical for commensal-induced periodontitis in a mouse model. Mice lacking Nod1 exhibit reduced bone resorption as well as impaired recruitment of neutrophils to gingival tissues and osteoclasts to the alveolar bone, which mediate tissue and bone destruction...
May 15, 2013: Cell Host & Microbe
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