This document reviews how probiotic bacterial surface molecules interact with host receptors, drawing comparisons to commensal and pathogenic bacteria. Probiotic cell wall molecules like polysaccharides and lipoteichoic acids interact with host pattern recognition receptors. This interaction can induce signaling pathways that result in probiotic effects on the host like exclusion of pathogens, enhancement of the intestinal barrier, and modulation of immune responses. The review discusses the known interactions between these probiotic surface molecules and host receptors, distinguishing probiotics from commensals and pathogens based on the specific molecules present and interactions mediated.
This document discusses antibiotics and their mechanisms of action. It begins by defining antibiotics and describing their targets in bacteria, such as cell wall synthesis, nucleic acid synthesis, and protein biosynthesis. It then discusses various classes of antibiotics like beta-lactams, quinolones, aminoglycosides, and macrolides. The document also covers antibiotic mechanisms like inhibition of cell wall, nucleic acid, and protein synthesis. It provides examples of antibiotics that target these different processes.
beta lactamases : structure , classification and investigationsDr Taoufik Djerboua
this is a simple introduction to the world of beta lactamase enzymes that i had the chance to present during my observership in turkey. it bears some introductive notions necessary to the unverstading of the function fo these enzymes and some tests usually used to invistigate bacteria producing these enzymes. the pictures were taken from Microbe-edu.com Bush et al classification of Beta lactamase, the EUCAST and CLSI recommandation for susceptibility testing documents.
This document discusses antimicrobial agents and antibiotics. It defines antimicrobial agents as chemicals that treat infectious diseases by inhibiting or killing pathogens. Ideal qualities of antimicrobial agents are listed. Antibiotics are defined as substances derived from microorganisms or produced synthetically that destroy or limit microbial growth. Various classifications of antibiotics are described based on their source, spectrum of activity, route of administration, and mechanism of action. The major mechanisms of action discussed are inhibition of cell wall synthesis, cell membrane function, protein synthesis, and nucleic acid synthesis. Bacterial resistance both intrinsic and acquired is also summarized.
Mechanisms of Antibacterial Drugs _ Microbiology.pdfLurthuPushparaj
This document discusses various classes of antibacterial drugs and their mechanisms of action. It describes drugs that inhibit bacterial cell wall biosynthesis like beta-lactams (penicillins, cephalosporins, carbapenems), glycopeptides, and bacitracin. It also covers drugs that inhibit bacterial protein synthesis, including aminoglycosides and tetracyclines which bind the 30S ribosomal subunit, and macrolides, lincosamides, and chloramphenicol which bind the 50S subunit. The document provides details on the structures, spectra of activity, and modes of action of representative drugs in each class.
Mechanism of action of major antibiotic classes including betal lactam agents, aminoglycosides, macrolides, tetracyclines, quinolons, vancomycin, oxazolidionons. Detailed review and illustrations
The document provides an overview of medical microbiology and bacteriology. It discusses various gram-positive and gram-negative cocci and their associated diseases. It then reviews the sites of antibiotic action in bacteria, including inhibition of cell wall synthesis by beta-lactams, cell membrane disruption by polymyxins, DNA inhibition by quinolones and metronidazole, inhibition of transcription by actinomycin D and rifampin, and inhibition of translation in the bacterial ribosome by various antibiotics classes that bind to the 30S or 50S subunits. It also discusses competitive antagonistic antibiotics that inhibit metabolic pathways like isoniazid, sulfonamides, and trimethoprim.
This document summarizes a lecture on the characteristics and classification of antibiotics. It discusses how antibiotics can be classified as either bactericidal or bacteriostatic based on their ability to kill bacteria versus prevent growth. Additional classifications include the target organism, spectrum of activity, and mechanism of action. Beta-lactam antibiotics like penicillins that inhibit cell wall synthesis are described in detail, focusing on their targets of penicillin binding proteins.
This document discusses antibiotics and their mechanisms of action. It begins by defining antibiotics and describing their targets in bacteria, such as cell wall synthesis, nucleic acid synthesis, and protein biosynthesis. It then discusses various classes of antibiotics like beta-lactams, quinolones, aminoglycosides, and macrolides. The document also covers antibiotic mechanisms like inhibition of cell wall, nucleic acid, and protein synthesis. It provides examples of antibiotics that target these different processes.
beta lactamases : structure , classification and investigationsDr Taoufik Djerboua
this is a simple introduction to the world of beta lactamase enzymes that i had the chance to present during my observership in turkey. it bears some introductive notions necessary to the unverstading of the function fo these enzymes and some tests usually used to invistigate bacteria producing these enzymes. the pictures were taken from Microbe-edu.com Bush et al classification of Beta lactamase, the EUCAST and CLSI recommandation for susceptibility testing documents.
This document discusses antimicrobial agents and antibiotics. It defines antimicrobial agents as chemicals that treat infectious diseases by inhibiting or killing pathogens. Ideal qualities of antimicrobial agents are listed. Antibiotics are defined as substances derived from microorganisms or produced synthetically that destroy or limit microbial growth. Various classifications of antibiotics are described based on their source, spectrum of activity, route of administration, and mechanism of action. The major mechanisms of action discussed are inhibition of cell wall synthesis, cell membrane function, protein synthesis, and nucleic acid synthesis. Bacterial resistance both intrinsic and acquired is also summarized.
Mechanisms of Antibacterial Drugs _ Microbiology.pdfLurthuPushparaj
This document discusses various classes of antibacterial drugs and their mechanisms of action. It describes drugs that inhibit bacterial cell wall biosynthesis like beta-lactams (penicillins, cephalosporins, carbapenems), glycopeptides, and bacitracin. It also covers drugs that inhibit bacterial protein synthesis, including aminoglycosides and tetracyclines which bind the 30S ribosomal subunit, and macrolides, lincosamides, and chloramphenicol which bind the 50S subunit. The document provides details on the structures, spectra of activity, and modes of action of representative drugs in each class.
Mechanism of action of major antibiotic classes including betal lactam agents, aminoglycosides, macrolides, tetracyclines, quinolons, vancomycin, oxazolidionons. Detailed review and illustrations
The document provides an overview of medical microbiology and bacteriology. It discusses various gram-positive and gram-negative cocci and their associated diseases. It then reviews the sites of antibiotic action in bacteria, including inhibition of cell wall synthesis by beta-lactams, cell membrane disruption by polymyxins, DNA inhibition by quinolones and metronidazole, inhibition of transcription by actinomycin D and rifampin, and inhibition of translation in the bacterial ribosome by various antibiotics classes that bind to the 30S or 50S subunits. It also discusses competitive antagonistic antibiotics that inhibit metabolic pathways like isoniazid, sulfonamides, and trimethoprim.
This document summarizes a lecture on the characteristics and classification of antibiotics. It discusses how antibiotics can be classified as either bactericidal or bacteriostatic based on their ability to kill bacteria versus prevent growth. Additional classifications include the target organism, spectrum of activity, and mechanism of action. Beta-lactam antibiotics like penicillins that inhibit cell wall synthesis are described in detail, focusing on their targets of penicillin binding proteins.
This document discusses antimicrobial resistance mechanisms. It covers natural resistance, acquired resistance, and various resistance mechanisms including biochemical mechanisms like reduced drug entry, efflux pumps, and drug inactivation. It also discusses mutation, gene transfer through transduction, transformation and conjugation, cross resistance, and strategies for preventing drug resistance like prudent antimicrobial use and combination therapy.
Antimicrobial agents and mechanisms of action 2Bruno Mmassy
The document discusses antibiotic resistance mechanisms in bacteria. It describes several key mechanisms:
1. Production of enzymes that inactivate antibiotics through destruction or modification. This includes beta-lactamases that break down beta-lactam antibiotics.
2. Decreased permeability of the cell membrane, preventing antibiotic penetration.
3. Active efflux of antibiotics from the bacterial cell via efflux pumps.
4. Modification of antibiotic target sites, such as altered penicillin-binding proteins or modifications to ribosomes.
Resistance can arise through mutation or acquisition of resistance genes via horizontal gene transfer. Multiple resistance mechanisms can provide high-level or multidrug resistance.
Antimicrobial agents and mechanisms of action 2Bruno Mmassy
This document discusses antimicrobial resistance and its mechanisms. It defines antimicrobial resistance and describes how it can arise through mutation or acquisition of genes. It covers various mechanisms of resistance such as production of inactivating enzymes, decreased permeability, efflux pumps, and modification of drug targets. It also discusses specific examples of resistance to beta-lactams, glycopeptides, and antibiotics that inhibit protein synthesis. Key terms related to drug-resistant organisms are defined.
Antibiotics are chemical substances that kill or inhibit the growth of microorganisms. They can be classified based on their source (natural, semisynthetic, synthetic), spectrum of activity (broad or narrow), or mechanism of action. Common mechanisms include inhibition of cell wall synthesis, protein synthesis, nucleic acid synthesis, and cell membrane function. Examples provided include penicillins, cephalosporins, carbapenems, glycopeptides, aminoglycosides, macrolides, quinolones, sulfonamides, and metronidazole.
This document discusses different classifications and mechanisms of antimicrobial agents. It describes how antibiotics can be classified based on their chemical structure, source, mechanism of action, spectrum of activity, and mode of action. The main mechanisms of antibiotic resistance are discussed, including production of enzymes to destroy antibiotics and alterations to cell membranes or metabolic pathways. Approaches to addressing resistance include proper antibiotic usage and selection based on accurate diagnosis and susceptibility testing.
The document discusses antimicrobial drug resistance (AMDR) and the mechanisms by which microbes develop resistance to antimicrobial medications. It describes classes of AMDR including resistance to antifungal, antiviral, antiprotozoal, and antibacterial drugs. Mechanisms of resistance include altering drug receptors or targets, reducing drug accumulation in cells, inactivating drugs, and developing resistant metabolic pathways. The document also summarizes the cellular and molecular mechanisms of antimicrobial action, including interfering with cell wall synthesis, plasma membrane integrity, nucleic acid synthesis, ribosomal function, and folate synthesis.
Chemotherapy uses chemicals to inhibit the growth of microorganisms and is used with other treatments like biological therapies, hormonal therapy, radiation therapy, and surgery. Antibiotics are produced by microorganisms and kill or inhibit the growth of other organisms. Chemotherapeutic agents target parasitic cells while being innocuous to host cells by exploiting biochemical differences between the parasite and host. There are three classes of biochemical reactions in bacteria that can be targeted: class I involves energy production, class II small molecule synthesis, and class III macromolecule assembly. Differences between bacterial and human cells allow some class III reactions like peptidoglycan cell wall synthesis to be targeted.
1. Antimicrobial resistance arises through genetic mutations and the acquisition of resistance genes from other bacteria.
2. Resistance genes can be acquired horizontally via mobile genetic elements such as plasmids, leading to rapid spread.
3. Common resistance mechanisms include enzymatic inactivation of antibiotics, modification or protection of antibiotic targets, and efflux pumps that pump out antibiotics.
This document discusses antimicrobial agents and chemotherapy. It begins by defining antibiotics as natural substances produced by microorganisms that suppress or kill other microorganisms. It then discusses antimicrobial agents, which include both naturally obtained and synthetic drugs that can attenuate microorganisms. Finally, it defines chemotherapeutic agents as drugs designed to inhibit or kill an infecting organism with minimal effect on the recipient. The document goes on to provide details on the classification, mechanisms, principles, development and prevention of antimicrobial resistance.
Antibacterial agents interfere with bacterial growth and reproduction by attacking bacteria. They include chemicals like chlorine, heat, and antibiotic drugs. Antibacterials are commonly used to disinfect surfaces and eliminate harmful bacteria. They are classified based on how they inhibit cell wall synthesis, protein synthesis, or bacterial nucleic acid synthesis. Antibacterials can directly dissolve bacterial cells or penetrate their walls and inactivate membrane transport systems to prevent nutrient uptake and survival. Bactericidal agents directly kill bacteria by disrupting cell walls or inhibiting formation of new cells. Bacteriostatic agents inhibit bacterial growth and multiplication by obstructing metabolic mechanisms like protein synthesis without outright cell death.
The document discusses several challenges with antimicrobial drug therapy, including problems with oral and intravenous drug delivery, poor tissue uptake, administering the wrong drug or at the wrong site, drug retention issues, and side effects. It also covers antimicrobial modes of action, sources of antibiotics, distinguishing characteristics of different antibiotics, and antibiotic resistance development and prevention strategies.
This document discusses mechanisms of antibiotic resistance in bacteria and biofilms. It describes how bacteria can develop intrinsic or acquired resistance. Major mechanisms of acquired resistance include decreased drug uptake through efflux pumps, drug inactivation by enzymes, changes in drug receptors, and use of alternative metabolic pathways. Biofilms make bacteria highly tolerant to antibiotics through extracellular polymeric substances that limit drug diffusion and concentration. New strategies to overcome resistance include quorum sensing inhibitors, biofilm-disrupting enzymes, low-frequency ultrasound, and flavonoids.
This document discusses the mechanisms of action of antimicrobial agents. It begins with a brief history of antimicrobial use from ancient times to the modern era. It then covers classifications of antimicrobials and their main mechanisms, which include inhibiting cell wall synthesis, cytoplasmic membrane function, nucleic acid synthesis, and ribosome function. Specific drug classes are discussed for each mechanism, such as penicillins, cephalosporins, and glycopeptides for cell wall inhibitors. The document concludes that understanding antimicrobial mechanisms of action is important for optimal patient care and preventing resistance.
This document discusses various types of antimicrobial drugs, including penicillin antibiotics. It explains that penicillin works by inhibiting the final stage of bacterial cell wall construction. It then describes different forms of penicillin like penicillin G, procaine penicillin, and benzathine penicillin. The document also discusses semisynthetic penicillins that were developed to have broader spectra and be resistant to penicillinases. Finally, it briefly mentions antiprotozoal drugs used to treat malaria and intestinal infections.
This document summarizes various structures and mechanisms in prokaryotic cells. It discusses biofilms, cell walls, membrane transport systems, secretion systems, flagella, pili, DNA transfer through transformation, transduction, and conjugation, as well as endospore formation. Bacterial adaptation is enabled by horizontal gene transfer including plasmids, transposons, and pathogenicity islands which facilitate the acquisition of virulence factors and antibiotic resistance.
This document discusses antibiotic resistance mechanisms. It defines antimicrobial resistance (AMR) as when microbes become insensitive to medicines, making infections harder to treat. AMR occurs through two main mechanisms: acquired resistance, where bacteria gain resistance genes, usually through overuse of antibiotics creating selective pressure; and intrinsic resistance, where bacteria innately resist certain drug classes. Bacteria develop resistance via decreased permeability, efflux pumps, enzymatic inactivation of drugs like beta-lactamases, and modifying drug targets. Resistance can be transmitted between bacteria through mutation or mobile genetic elements like plasmids.
1) Lantibiotics are a class of antimicrobial peptides that contain thioether amino acids and dehydrated amino acids. They are ribosomally synthesized as precursor peptides and undergo post-translational modifications to become biologically active.
2) Lantibiotics act by binding to lipid II, which is involved in bacterial cell wall biosynthesis, inhibiting its function. This disrupts cell wall synthesis and can lead to pore formation.
3) Salivaricins are lantibiotics produced by Streptococcus salivarius that inhibit pathogenic oral bacteria and have potential as probiotics. They demonstrate activity against bacteria involved in dental caries, gingivitis, and oral malodor.
This document discusses the potential health benefits and mechanisms of action of probiotics. It describes how probiotics can promote gastrointestinal health through competitive exclusion of pathogens, production of antimicrobial compounds, immunomodulation, and reinforcement of the intestinal barrier. The document also discusses how probiotics may help alleviate lactose intolerance by digesting lactose and increasing lactose tolerance. It explores the potential for probiotics to inhibit harmful bacteria like Helicobacter pylori through organic acid production, bacteriocin secretion, and inhibition of adhesion to gastric cells.
This document discusses antimicrobial resistance mechanisms. It covers natural resistance, acquired resistance, and various resistance mechanisms including biochemical mechanisms like reduced drug entry, efflux pumps, and drug inactivation. It also discusses mutation, gene transfer through transduction, transformation and conjugation, cross resistance, and strategies for preventing drug resistance like prudent antimicrobial use and combination therapy.
Antimicrobial agents and mechanisms of action 2Bruno Mmassy
The document discusses antibiotic resistance mechanisms in bacteria. It describes several key mechanisms:
1. Production of enzymes that inactivate antibiotics through destruction or modification. This includes beta-lactamases that break down beta-lactam antibiotics.
2. Decreased permeability of the cell membrane, preventing antibiotic penetration.
3. Active efflux of antibiotics from the bacterial cell via efflux pumps.
4. Modification of antibiotic target sites, such as altered penicillin-binding proteins or modifications to ribosomes.
Resistance can arise through mutation or acquisition of resistance genes via horizontal gene transfer. Multiple resistance mechanisms can provide high-level or multidrug resistance.
Antimicrobial agents and mechanisms of action 2Bruno Mmassy
This document discusses antimicrobial resistance and its mechanisms. It defines antimicrobial resistance and describes how it can arise through mutation or acquisition of genes. It covers various mechanisms of resistance such as production of inactivating enzymes, decreased permeability, efflux pumps, and modification of drug targets. It also discusses specific examples of resistance to beta-lactams, glycopeptides, and antibiotics that inhibit protein synthesis. Key terms related to drug-resistant organisms are defined.
Antibiotics are chemical substances that kill or inhibit the growth of microorganisms. They can be classified based on their source (natural, semisynthetic, synthetic), spectrum of activity (broad or narrow), or mechanism of action. Common mechanisms include inhibition of cell wall synthesis, protein synthesis, nucleic acid synthesis, and cell membrane function. Examples provided include penicillins, cephalosporins, carbapenems, glycopeptides, aminoglycosides, macrolides, quinolones, sulfonamides, and metronidazole.
This document discusses different classifications and mechanisms of antimicrobial agents. It describes how antibiotics can be classified based on their chemical structure, source, mechanism of action, spectrum of activity, and mode of action. The main mechanisms of antibiotic resistance are discussed, including production of enzymes to destroy antibiotics and alterations to cell membranes or metabolic pathways. Approaches to addressing resistance include proper antibiotic usage and selection based on accurate diagnosis and susceptibility testing.
The document discusses antimicrobial drug resistance (AMDR) and the mechanisms by which microbes develop resistance to antimicrobial medications. It describes classes of AMDR including resistance to antifungal, antiviral, antiprotozoal, and antibacterial drugs. Mechanisms of resistance include altering drug receptors or targets, reducing drug accumulation in cells, inactivating drugs, and developing resistant metabolic pathways. The document also summarizes the cellular and molecular mechanisms of antimicrobial action, including interfering with cell wall synthesis, plasma membrane integrity, nucleic acid synthesis, ribosomal function, and folate synthesis.
Chemotherapy uses chemicals to inhibit the growth of microorganisms and is used with other treatments like biological therapies, hormonal therapy, radiation therapy, and surgery. Antibiotics are produced by microorganisms and kill or inhibit the growth of other organisms. Chemotherapeutic agents target parasitic cells while being innocuous to host cells by exploiting biochemical differences between the parasite and host. There are three classes of biochemical reactions in bacteria that can be targeted: class I involves energy production, class II small molecule synthesis, and class III macromolecule assembly. Differences between bacterial and human cells allow some class III reactions like peptidoglycan cell wall synthesis to be targeted.
1. Antimicrobial resistance arises through genetic mutations and the acquisition of resistance genes from other bacteria.
2. Resistance genes can be acquired horizontally via mobile genetic elements such as plasmids, leading to rapid spread.
3. Common resistance mechanisms include enzymatic inactivation of antibiotics, modification or protection of antibiotic targets, and efflux pumps that pump out antibiotics.
This document discusses antimicrobial agents and chemotherapy. It begins by defining antibiotics as natural substances produced by microorganisms that suppress or kill other microorganisms. It then discusses antimicrobial agents, which include both naturally obtained and synthetic drugs that can attenuate microorganisms. Finally, it defines chemotherapeutic agents as drugs designed to inhibit or kill an infecting organism with minimal effect on the recipient. The document goes on to provide details on the classification, mechanisms, principles, development and prevention of antimicrobial resistance.
Antibacterial agents interfere with bacterial growth and reproduction by attacking bacteria. They include chemicals like chlorine, heat, and antibiotic drugs. Antibacterials are commonly used to disinfect surfaces and eliminate harmful bacteria. They are classified based on how they inhibit cell wall synthesis, protein synthesis, or bacterial nucleic acid synthesis. Antibacterials can directly dissolve bacterial cells or penetrate their walls and inactivate membrane transport systems to prevent nutrient uptake and survival. Bactericidal agents directly kill bacteria by disrupting cell walls or inhibiting formation of new cells. Bacteriostatic agents inhibit bacterial growth and multiplication by obstructing metabolic mechanisms like protein synthesis without outright cell death.
The document discusses several challenges with antimicrobial drug therapy, including problems with oral and intravenous drug delivery, poor tissue uptake, administering the wrong drug or at the wrong site, drug retention issues, and side effects. It also covers antimicrobial modes of action, sources of antibiotics, distinguishing characteristics of different antibiotics, and antibiotic resistance development and prevention strategies.
This document discusses mechanisms of antibiotic resistance in bacteria and biofilms. It describes how bacteria can develop intrinsic or acquired resistance. Major mechanisms of acquired resistance include decreased drug uptake through efflux pumps, drug inactivation by enzymes, changes in drug receptors, and use of alternative metabolic pathways. Biofilms make bacteria highly tolerant to antibiotics through extracellular polymeric substances that limit drug diffusion and concentration. New strategies to overcome resistance include quorum sensing inhibitors, biofilm-disrupting enzymes, low-frequency ultrasound, and flavonoids.
This document discusses the mechanisms of action of antimicrobial agents. It begins with a brief history of antimicrobial use from ancient times to the modern era. It then covers classifications of antimicrobials and their main mechanisms, which include inhibiting cell wall synthesis, cytoplasmic membrane function, nucleic acid synthesis, and ribosome function. Specific drug classes are discussed for each mechanism, such as penicillins, cephalosporins, and glycopeptides for cell wall inhibitors. The document concludes that understanding antimicrobial mechanisms of action is important for optimal patient care and preventing resistance.
This document discusses various types of antimicrobial drugs, including penicillin antibiotics. It explains that penicillin works by inhibiting the final stage of bacterial cell wall construction. It then describes different forms of penicillin like penicillin G, procaine penicillin, and benzathine penicillin. The document also discusses semisynthetic penicillins that were developed to have broader spectra and be resistant to penicillinases. Finally, it briefly mentions antiprotozoal drugs used to treat malaria and intestinal infections.
This document summarizes various structures and mechanisms in prokaryotic cells. It discusses biofilms, cell walls, membrane transport systems, secretion systems, flagella, pili, DNA transfer through transformation, transduction, and conjugation, as well as endospore formation. Bacterial adaptation is enabled by horizontal gene transfer including plasmids, transposons, and pathogenicity islands which facilitate the acquisition of virulence factors and antibiotic resistance.
This document discusses antibiotic resistance mechanisms. It defines antimicrobial resistance (AMR) as when microbes become insensitive to medicines, making infections harder to treat. AMR occurs through two main mechanisms: acquired resistance, where bacteria gain resistance genes, usually through overuse of antibiotics creating selective pressure; and intrinsic resistance, where bacteria innately resist certain drug classes. Bacteria develop resistance via decreased permeability, efflux pumps, enzymatic inactivation of drugs like beta-lactamases, and modifying drug targets. Resistance can be transmitted between bacteria through mutation or mobile genetic elements like plasmids.
1) Lantibiotics are a class of antimicrobial peptides that contain thioether amino acids and dehydrated amino acids. They are ribosomally synthesized as precursor peptides and undergo post-translational modifications to become biologically active.
2) Lantibiotics act by binding to lipid II, which is involved in bacterial cell wall biosynthesis, inhibiting its function. This disrupts cell wall synthesis and can lead to pore formation.
3) Salivaricins are lantibiotics produced by Streptococcus salivarius that inhibit pathogenic oral bacteria and have potential as probiotics. They demonstrate activity against bacteria involved in dental caries, gingivitis, and oral malodor.
This document discusses the potential health benefits and mechanisms of action of probiotics. It describes how probiotics can promote gastrointestinal health through competitive exclusion of pathogens, production of antimicrobial compounds, immunomodulation, and reinforcement of the intestinal barrier. The document also discusses how probiotics may help alleviate lactose intolerance by digesting lactose and increasing lactose tolerance. It explores the potential for probiotics to inhibit harmful bacteria like Helicobacter pylori through organic acid production, bacteriocin secretion, and inhibition of adhesion to gastric cells.
This study investigated the effects of the probiotic Bifidobacterium breve CNCM I-4035 and its cell-free culture supernatant (CFS) on human dendritic cells (DCs) and how the DCs respond to the pathogenic bacteria Salmonella typhi. The CFS decreased pro-inflammatory cytokines in DCs challenged with S. typhi, while live B. breve induced both pro- and anti-inflammatory cytokines. Both live B. breve and CFS activated Toll-like receptor signaling pathways in DCs. CFS increased expression of TLR9 and related genes more than live B. breve in the presence of S. typhi. The results suggest B. breve affects the
The document discusses the role of gut microbiota in nutrition and health. It makes three key points:
1) The gut microbiota contributes nutrients and energy to the host through fermenting nondigestible dietary components, and maintains a balance with the host's metabolism and immune system in a healthy state.
2) Diet has a major influence on microbial community composition in both the short and long term, opening possibilities for manipulating health through diet.
3) There is significant interindividual variation in gut microbiota composition within populations that influences responses to drugs and diet. Achieving a better understanding of microbiota profiles that support health is important.
HOST MICROBIAL INTERACTIONS
CONTENTS
MICROBIAL ASPECTS OF HOST MICROBIAL INTERACTIONS
1. Bacterial Colonization and Survival in the Periodontal Region
2. Microbial Mechanisms of Host Tissue Damage
MOLECULAR ASPECTS OF HOST MICROBIAL INTERACTIONS
1. Microbe-Associated Molecular Patterns (MAMPs)
2. Pattern Recognition Receptors (PRRs)
Toll-Like Receptors (TLRs)
NOD-Like Receptors (NLRs)
3. Complement System
Antimicrobial peptides
MICROBIAL ASPECTS OF HOST MICROBIAL INTERACTIONS
Gingivitis and periodontitis are chronic infectious diseases.
The interaction of the microorganism with the host determines the course and extent of the resulting disease.
Microorganisms may exert pathogenic effects directly by causing tissue destruction or indirectly by stimulating and modulating host responses.
The host response is mediated by the microbial interaction and inherent characteristics of the host, including genetic factors that vary among individuals.
In general, the host response functions in a protective capacity by preventing the local infection from progressing to a systemic, life-threatening infection. However, local alteration and destruction of host tissues as a result of the microbial-host interactions may manifest as periodontal disease.
The varying balance between locally harmful and beneficial effects of the pathogenic microorganisms and the host accounts for the wide variety of patterns of tissue changes observed among patients.
In periodontitis, the initial step in the disease process is the colonization of the periodontal tissues by pathogenic species.
Entry of the bacterium itself (invasion) or of bacterial products into the periodontal tissues may be important in the disease process.
Furthermore, inherent in successful colonization of host tissues is the ability of the bacterium to evade host defense mechanisms aimed at eliminating the bacterium from the periodontal environment.
BACTERIAL COLONIZATION AND SURVIVAL IN THE PERIODONTAL REGION
Bacterial Adherence in the Periodontal Environment
The gingival sulcus and periodontal pocket are bathed in gingival crevicular fluid, which flows outward from the base of the pocket.
Bacterial species that colonize this region must attach to available surfaces to avoid displacement by the fluid flow. Therefore, adherence represents a virulence factor for periodontal pathogens.
Bacteria may enter host tissues through ulcerations in the epithelium of the gingival sulcus or pocket and/ or direct penetration of bacteria into host epithelial or connective tissue cells.
Laboratory investigations have demonstrated the ability of A. actinomycetemcomitans, P. gingivalis, F. nucleatum, and Treponema denticola to invade host tissue cells directly.
COMPLEMENT SYSTEM
The periodontal host immune response is dependent on a functional complement system, which notably coordinates the recruitment and activation of immune cells, bacterial opsonization, phagocytosis, and lysis.
Microbiata
A main player in immunityThe microbiome is an environmental factor in intricate symbiotic relationship with its hosts' immune system, potentially shaping:
anticancer immunity,
autoimmunity, and
transplant responses
MBB611 Microbiome signature and applicationBARAKA NGINGO
The document discusses the human microbiome and microbiome signatures. It defines key terms like microbiota, microbiome, and microbiome signatures. The gut microbiome contains trillions of microbes belonging to over 1000 unique species. The microbiome plays important roles in metabolism, immune function, and preventing pathogenic infection. Changes in the gut microbiome have been linked to various diseases. Studying the microbiome involves both culture-dependent and culture-independent methods like metagenomics, which uses high-throughput DNA sequencing without culturing to characterize microbial communities.
This document proposes creating an in vitro gut biofilm model capable of sustaining multiple bacterial species. The researchers will 3D print Lactobacillus and Bifidobacterium bacteria onto a porous mucin membrane within a device consisting of two layers separated by the membrane. Nutrients, food, and waste can diffuse through the membrane, allowing the bacteria to communicate via quorum sensing while being physically separated. Experiments will manipulate environmental factors like pH, temperature, and nutrients to determine optimal conditions for the long-term coexistence of both bacterial species, overcoming the "winner takes all" phenomenon seen in previous single-species models. If successful, this model could be used to study probiotics and gut bacteria responses without human testing.
This document reviews the relationship between commensal bacteria in the mammalian gut and the host immune system. It discusses how a polysaccharide molecule called ZPS, produced by the commensal bacteria Bacteroides fragilis, activates CD4+ T cells and influences immune system development. Studies found that ZPS elicits a unique immune response for a bacterial polysaccharide by inducing T cell responses rather than acting as a classic T cell-independent antigen. The immunodominant polysaccharide from B. fragilis, called PSA, was found to have this zwitterionic property and to protect against abscess formation in a T cell-dependent manner.
BIOLOGICAL CONTROL OF SOIL BORNE and AERIAL PATHOGENS OF CROP PLANTSHARISH J
This document discusses biological control of plant pathogens through antagonistic microorganisms. It begins by defining biological control and listing some common biocontrol agents like Trichoderma, Penicillium, and Bacillus. It then explains the various mechanisms biocontrol agents use, including antibiosis, siderophore production, induced systemic resistance, competition, and parasitism. The document provides examples of soilborne and aerial plant pathogens and their corresponding diseases. It concludes by stating that while commercial use of biocontrol agents is currently limited, their use is expected to increase as farming communities become more comfortable with their efficiency and safety compared to chemicals.
This document discusses objectives and research questions related to determining the minimum inhibitory concentration (MIC) values for various bacteria using antibiotic susceptibility testing. It aims to identify how disc susceptibility tests can be used in the antibiotic drug discovery process. It also provides background on bacterial cell anatomy, classifications of antibiotics by their mechanisms of action including targeting cell walls, protein biosynthesis, DNA replication, and folic acid metabolism. Mechanisms of antibiotic resistance for bacteria include reduced outer membrane permeability, efflux pumps, target molecule modification, and enzymatic inactivation or modification of antibiotics.
Role of membrane architecture in development of sensitivity to cephalosporin ...Alexander Decker
This document discusses the role of membrane architecture in the development of sensitivity to cephalosporin antibiotics. It notes that gram-positive and gram-negative bacteria differ in their cell wall structure, with gram-negative bacteria having a more complex structure including an outer membrane. Experiments studied the effects of the cephalosporins ceftriaxone and cefazolin on Bacillus subtilis (gram-positive) and Escherichia coli (gram-negative), finding that cefazolin led to higher protein release from intact cells and membrane vesicles. The extent of protein release was also affected by temperature and EDTA concentration treatments. The orientation of the outer membrane was found to determine the therapeutic value of these
The term probiotics is a relatievly new word meaning “for life” and is currently used to name bacteria associated with beneficial effects for humans and animals. The development of resistance to range of antibiotics by some important pathogen has raised a possibility of return to pre antibiotic dark ages. So there was need of new treatment paradigm to be introduced to treat periodontal diseases. This need was fulfilled by the introduction of probiotics. Probiotics are counterparts of antibiotics thus are free from concerns for developing resistance, further they are body’s own resident flora hence are most easily adapted to host. The buzz about probiotics has become a roar but despite great promises, probiotics work is limited to gut. Periodontal works are sparse and need validation by large randomized trials. It can be said probiotics are still in “infancy” in terms of periodontal health benefits, but surely have opened door for a new paradigm of treating disease on a nano molecular mode. Novel species are likely to be added in the future as research data
accumulate. In-depth understanding of the intrinsic microbial ecological control of commensal microbiota may introduce new putative species to this discussion.
This document discusses microbial cell factories and metabolic engineering. It defines microbial cell factories as microbial cells engineered as production facilities through metabolic engineering, which alters metabolic pathways for chemical production. Metabolic engineering draws from various disciplines to engineer metabolic pathways to increase productivity of antibiotics, polymers, and more. The document also discusses primary and secondary metabolites, with primary metabolites essential for growth and secondary metabolites having various industrial uses like antibiotics. Strategies for overproducing both types of metabolites include genetic engineering of pathways and eliciting microbial responses through stress factors or quorum sensing.
1. The document discusses gut microflora and its role in susceptibility of lepidopteran pests to Bacillus thuringiensis (Bt). It covers types of insect-microbe interactions like pathogenic, symbiotic, and their characteristics.
2. Methods for analyzing gut microflora diversity are described, including gene targeting, molecular fingerprinting, fluorescent in situ hybridization, and metagenomics. Studies on the diversity of gut microflora in various lepidopterans are presented.
3. The role of gut microflora in influencing Bt susceptibility is explored through case studies on enzymes, siderophores, competition with pathogens, and synergistic activity with Bt. The document concludes
1. Periodontal diseases are caused by complex biofilms containing multiple bacterial species that interact with host tissues. A key group is the "red complex" comprising Porphyromonas gingivalis, Treponema denticola, and Tanerella forsythia.
2. These bacteria employ various virulence factors to adhere to surfaces, acquire nutrients, and evade the host immune response in order to colonize and cause disease. Important factors include fimbriae, proteases, and capsules that aid adhesion and facilitate tissue destruction.
3. P. gingivalis possesses specific fimbriae, proteases, and a capsule that help it adhere, acquire iron through hemol
Engineering of Phage-Derived Lytic Enzymes: Improving Their Potential as Antimicrobials
Carlos São-José
ID
Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa,
Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal; csaojose@ff.ul.pt; Tel.: +351-217-946-420
The document discusses developments in microbiome-based therapeutics. It outlines how advances in omics approaches have improved understanding of the gut microbiome's role in health and disease. Several approaches for microbiome-based therapeutics are discussed, including probiotics, prebiotics, postbiotics, and fecal microbiota transplantation. Challenges including determining causative relationships and altering microbial communities are also summarized. The document concludes that more research is still needed but that microbiome therapeutics have significant potential to treat gastrointestinal and other diseases.
In recent years, the increase in the number of multi-drug resistant pathogens and food safety have become serious global problems, and it is increasingly important to find or develop a new generation of antibacterial drugs or preservatives. Scientists have discovered that bacteria-produced bacteriocins can control clinically relevant susceptible and resistant bacteria, and purified bacteriocins can be added to foods as natural preservatives. Bacteriocins can be added to animal feeds as anti-pathogen additives to protect livestock from pathogen damage. In medicine, bacteriocin has the potential to replace antibiotics as antibacterial drugs and is a new type of anticancer drug.
Similar to Host Interactions Of Probiotic Bacterial Surface Molecules Comparison With Commensals And Pathogens (20)
La Unión Europea ha acordado un paquete de sanciones contra Rusia por su invasión de Ucrania. Las sanciones incluyen restricciones a las importaciones de productos rusos clave como el acero y la madera, así como medidas contra bancos y funcionarios rusos. Los líderes de la UE esperan que las sanciones aumenten la presión económica sobre Rusia y la disuadan de continuar su agresión contra Ucrania.
El documento presenta el cronograma de actividades para un programa de verano científico que incluye tres etapas: aislamiento y purificación de péptidos naturales, bioensayos in vitro de los péptidos, y taxonomía molecular y genética. La primera etapa involucra técnicas de aislamiento como extracción con nitrógeno líquido y centrifugación, así como purificación mediante cromatografía líquida de baja presión y espectrometría de masas. La segunda etapa implica bioensayos de los pépt
Zhao Liping is a Chinese microbiologist who studied his own microbiome to understand obesity. After gaining significant weight, he adopted a regimen of fermented foods like Chinese yam and bitter melon believed to change gut bacteria. This led to weight loss of 20 kg in 2 years along with improved health markers. His personal experience inspired him to research the role of the microbiome in conditions like diabetes and obesity. While the field is still young, Zhao hopes to establish a molecular pathway between gut microbes and obesity through human and animal studies.
A study found that consuming milk fat promotes growth of normally rare sulphate-reducing bacteria in mice, which stimulates harmful immune responses and causes more severe colitis in mice genetically prone to inflammatory bowel disease (IBD). Milk fat increases taurine-conjugated bile acids that feed these bacteria, namely Bilophilia wadsworthia, leading them to produce metabolites like hydrogen sulfide that damage the gut. These findings help explain how certain diets may influence IBD by altering the gut microbiome in genetically susceptible individuals.
1) The gut microbiota is now a major focus of research across many disciplines due to its contributions to health and disease.
2) Changes in the composition of the gut microbiota are linked to changes in human behavior and the rising prevalence of immune and metabolic disorders.
3) Discoveries about the gut microbiota promise to realize personalized medicine and nutrition and change conventional dietary management approaches.
1) The gut microbiota plays a key role in host development, physiology, and health by modulating the immune system and influencing organ development and metabolism.
2) The gut microbiota is dominated by anaerobic bacteria and contains over 500-1000 bacterial species from a few bacterial phyla. It outnumbers human cells 10:1 and contains many metabolic functions.
3) The gut microbiota influences the properties of the intestinal mucus layer, induces the development of lymphoid structures, and tailors immune development through effects on both the innate and adaptive immune systems.
The Human Microbiome Project Consortium established a population-scale framework to study the human microbiome through standardized protocols. They obtained samples from 15-18 body sites from 242 healthy adults over multiple time points. They generated over 5,000 microbial profiles from 16S rRNA genes and over 3.5 terabases of metagenomic sequence data. They also sequenced approximately 800 reference strains isolated from the human body. Collectively, these data and resources represent the largest collection of human microbiome data and provide a framework for current and future microbiome studies.
This document summarizes recent findings that challenge the traditional definitions of innate and adaptive immunity. It provides three examples of studies that found evidence of immune specificity and memory in invertebrates like water fleas and copepods. It also notes that while mammals use immunoglobulins for antigen recognition, other phyla use different receptor systems, and that innate immune systems may be more complex than originally believed. The growing evidence from diverse species suggests a blurring of the lines between innate and adaptive immunity.
1) The gut microbiota plays a key role in host development, physiology, and health by modulating the immune system and influencing organ development and metabolism.
2) The gut microbiota is dominated by anaerobic bacteria and contains over 500-1000 bacterial species from a few bacterial phyla. It outnumbers human cells 10:1 and contains many metabolic functions.
3) The gut microbiota influences the properties of the intestinal mucus layer, induces the development of lymphoid structures, and tailors immune development through effects on both the innate and adaptive immune systems.
This document summarizes a scientific paper that analyzed the genome of the sea urchin to gain insights into its immune system. The analysis of the sea urchin genome revealed a diverse set of immune genes similar to those found in jawed vertebrates. This suggests the sea urchin has a complex immune system reliant on specialized immune cells. The findings provide a more in-depth understanding of the evolution of the immune system in invertebrate animals.
This document summarizes a study that investigated the antibacterial activity in different tissues of four marine crustacean species: northern shrimp (Pandalus borealis), hermit crab (Pagurus bernhardus), spider crab (Hyas araneus), and king crab (Paralithodes camtschatica). Extracts were prepared from tissues including haemolymph, haemocytes, exoskeleton, gills, and internal organs. The extracts were tested for antibacterial activity against four bacterial strains. Antibacterial activity was detected in extracts from several tissues in all species, mainly in haemolymph and haemocyte extracts. Differences in activity between extracts and sensitivity to heat and enzymes suggested multiple antibacterial compounds are
This study examines the antimicrobial and antibiofilm activity of a 5-kDa peptide fraction isolated from the coelomocytes (immune cells) of the sea urchin Paracentrotus lividus. The peptide fraction, called 5-CC, showed inhibitory activity against both Gram-positive and Gram-negative bacteria, as well as fungi, with minimum inhibitory concentrations ranging from 253.7 to 15.8 mg ml-1. 5-CC also inhibited the formation of Staphylococcus aureus and Staphylococcus epidermidis biofilms. At sub-MIC concentrations, 5-CC inhibited the formation of young (6-hour) and mature (24-hour) biofilms of
El documento trata sobre la investigación científica. Presenta nuevos hallazgos sobre un tema específico de la ciencia. Los resultados contribuyen al conocimiento actual sobre el tema y sugieren más investigaciones futuras.
Este documento presenta los resultados de un estudio sobre el uso de un extracto de piel de rana catesbeiana como tratamiento alternativo para la mastitis clínica en bovinos. El extracto redujo el número de bacterias causantes de mastitis y mejoró el tejido glandular dañado. Además, el extracto redujo el grado de mastitis en vacas tratadas, especialmente mastitis moderada. Finalmente, el documento propone la creación de un laboratorio para aislar y purificar péptidos antimicrobianos de la rana con fines biotecnoló
La propuesta propone crear un laboratorio para aislar y purificar sustancias naturales con aplicaciones biotecnológicas. El laboratorio se enfocaría en secuenciar y sintetizar péptidos antimicrobianos de la rana catesbeiana para desarrollar tratamientos para infecciones. La propuesta describe la infraestructura requerida como consultoras y centros de investigación que brindarían apoyo.
Este documento presenta un cuestionario de 31 preguntas sobre conceptos básicos de microbiología. Las preguntas abarcan temas como los descubridores clave en el campo de la microbiología, la morfología y estructura de las bacterias, sus mecanismos de movilidad y reproducción, así como las funciones de sus principales estructuras celulares como la membrana, pared celular, flagelos y ribosomas. El cuestionario parece ser parte de un examen o evaluación para estudiantes de microbiología.
The document describes the discovery of a new basal clade within the fungal kingdom called cryptomycota.
- Cryptomycota includes organisms like Rozella that branch with fungi genetically but appear to grow and develop without synthesizing a chitin-rich cell wall, which is a defining characteristic of fungi.
- Phylogenetic trees constructed from genetic data place cryptomycota as a sister group to Rozella and identify it as a very large, uncultured group of microbes that fundamentally challenges current understanding of fungal evolution and diversity.
This document summarizes the current understanding of fungal hyphal branching. It discusses the two main types of branching (apical and lateral) and some of the internal and external factors that induce branching. Potential mechanisms underlying branch site selection are outlined, including multiple signaling pathways and subcellular structures. Finally, branching in other kingdoms is briefly compared to fungal hyphal branching. However, the molecular basis of hyphal branching remains poorly understood.
The document discusses fungal infections and the immune response to fungi. It notes that fungi can have symbiotic, commensal, latent, or pathogenic relationships with humans. The immune system aims to limit fungal burden through resistance, and limit host damage through tolerance. Both resistance and tolerance strategies are evolutionarily conserved in plants and vertebrates. Understanding the interplay between these strategies may help define how fungi have adapted to the mammalian immune system.
Level 3 NCEA - NZ: A Nation In the Making 1872 - 1900 SML.pptHenry Hollis
The History of NZ 1870-1900.
Making of a Nation.
From the NZ Wars to Liberals,
Richard Seddon, George Grey,
Social Laboratory, New Zealand,
Confiscations, Kotahitanga, Kingitanga, Parliament, Suffrage, Repudiation, Economic Change, Agriculture, Gold Mining, Timber, Flax, Sheep, Dairying,
This presentation was provided by Racquel Jemison, Ph.D., Christina MacLaughlin, Ph.D., and Paulomi Majumder. Ph.D., all of the American Chemical Society, for the second session of NISO's 2024 Training Series "DEIA in the Scholarly Landscape." Session Two: 'Expanding Pathways to Publishing Careers,' was held June 13, 2024.
How Barcodes Can Be Leveraged Within Odoo 17Celine George
In this presentation, we will explore how barcodes can be leveraged within Odoo 17 to streamline our manufacturing processes. We will cover the configuration steps, how to utilize barcodes in different manufacturing scenarios, and the overall benefits of implementing this technology.
THE SACRIFICE HOW PRO-PALESTINE PROTESTS STUDENTS ARE SACRIFICING TO CHANGE T...indexPub
The recent surge in pro-Palestine student activism has prompted significant responses from universities, ranging from negotiations and divestment commitments to increased transparency about investments in companies supporting the war on Gaza. This activism has led to the cessation of student encampments but also highlighted the substantial sacrifices made by students, including academic disruptions and personal risks. The primary drivers of these protests are poor university administration, lack of transparency, and inadequate communication between officials and students. This study examines the profound emotional, psychological, and professional impacts on students engaged in pro-Palestine protests, focusing on Generation Z's (Gen-Z) activism dynamics. This paper explores the significant sacrifices made by these students and even the professors supporting the pro-Palestine movement, with a focus on recent global movements. Through an in-depth analysis of printed and electronic media, the study examines the impacts of these sacrifices on the academic and personal lives of those involved. The paper highlights examples from various universities, demonstrating student activism's long-term and short-term effects, including disciplinary actions, social backlash, and career implications. The researchers also explore the broader implications of student sacrifices. The findings reveal that these sacrifices are driven by a profound commitment to justice and human rights, and are influenced by the increasing availability of information, peer interactions, and personal convictions. The study also discusses the broader implications of this activism, comparing it to historical precedents and assessing its potential to influence policy and public opinion. The emotional and psychological toll on student activists is significant, but their sense of purpose and community support mitigates some of these challenges. However, the researchers call for acknowledging the broader Impact of these sacrifices on the future global movement of FreePalestine.
Gender and Mental Health - Counselling and Family Therapy Applications and In...PsychoTech Services
A proprietary approach developed by bringing together the best of learning theories from Psychology, design principles from the world of visualization, and pedagogical methods from over a decade of training experience, that enables you to: Learn better, faster!
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إضغ بين إيديكم من أقوى الملازم التي صممتها
ملزمة تشريح الجهاز الهيكلي (نظري 3)
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تتميز هذهِ الملزمة بعِدة مُميزات :
1- مُترجمة ترجمة تُناسب جميع المستويات
2- تحتوي على 78 رسم توضيحي لكل كلمة موجودة بالملزمة (لكل كلمة !!!!)
#فهم_ماكو_درخ
3- دقة الكتابة والصور عالية جداً جداً جداً
4- هُنالك بعض المعلومات تم توضيحها بشكل تفصيلي جداً (تُعتبر لدى الطالب أو الطالبة بإنها معلومات مُبهمة ومع ذلك تم توضيح هذهِ المعلومات المُبهمة بشكل تفصيلي جداً
5- الملزمة تشرح نفسها ب نفسها بس تكلك تعال اقراني
6- تحتوي الملزمة في اول سلايد على خارطة تتضمن جميع تفرُعات معلومات الجهاز الهيكلي المذكورة في هذهِ الملزمة
واخيراً هذهِ الملزمة حلالٌ عليكم وإتمنى منكم إن تدعولي بالخير والصحة والعافية فقط
كل التوفيق زملائي وزميلاتي ، زميلكم محمد الذهبي 💊💊
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Philippine Edukasyong Pantahanan at Pangkabuhayan (EPP) CurriculumMJDuyan
(𝐓𝐋𝐄 𝟏𝟎𝟎) (𝐋𝐞𝐬𝐬𝐨𝐧 𝟏)-𝐏𝐫𝐞𝐥𝐢𝐦𝐬
𝐃𝐢𝐬𝐜𝐮𝐬𝐬 𝐭𝐡𝐞 𝐄𝐏𝐏 𝐂𝐮𝐫𝐫𝐢𝐜𝐮𝐥𝐮𝐦 𝐢𝐧 𝐭𝐡𝐞 𝐏𝐡𝐢𝐥𝐢𝐩𝐩𝐢𝐧𝐞𝐬:
- Understand the goals and objectives of the Edukasyong Pantahanan at Pangkabuhayan (EPP) curriculum, recognizing its importance in fostering practical life skills and values among students. Students will also be able to identify the key components and subjects covered, such as agriculture, home economics, industrial arts, and information and communication technology.
𝐄𝐱𝐩𝐥𝐚𝐢𝐧 𝐭𝐡𝐞 𝐍𝐚𝐭𝐮𝐫𝐞 𝐚𝐧𝐝 𝐒𝐜𝐨𝐩𝐞 𝐨𝐟 𝐚𝐧 𝐄𝐧𝐭𝐫𝐞𝐩𝐫𝐞𝐧𝐞𝐮𝐫:
-Define entrepreneurship, distinguishing it from general business activities by emphasizing its focus on innovation, risk-taking, and value creation. Students will describe the characteristics and traits of successful entrepreneurs, including their roles and responsibilities, and discuss the broader economic and social impacts of entrepreneurial activities on both local and global scales.