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Probiotics and biofilms


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Probiotics and biofilms

  1. 1. Probiotics and Biofilms By : Tewdros Tesfa (BSc., MSc.) Haramaya University Wondmagegn Demsiss (BSc., MSc.) Wollo University Probiotics and biofilms TW 1
  2. 2. Outline 2  Probiotics  Mechanism of action of probiotics  Introduction About biofilm  Formation, development and dispersal of biofilms  Properties of biofilms and Quorum sensing  Uses and problems of biofilms  Biofilms and infectious diseases  Control and removal of biofilms Probiotics and biofilms TW
  3. 3. Objectives 3 At the end of this presentation you will be able to:  Define biofilms and Probiotics  Understand the mechanism of action of Probiotics  Describe how biofilms are formed.  State the role of biofilms in infectious disease.  Understand the antimicrobial drug resistance mechanisms of biofilms.  Know the prevention and control mechanism of biofilms. Probiotics and biofilms TW
  4. 4. Definition 4  Live microorganisms which when administered in adequate amounts confer a health benefit on the host” (FAO/WHO, 2002)  Are live microorganisms; could be fungi or bacteria  Food ingredients  Have beneficial health effects e.g. Lactobacillus, Bifidobacterium, Saccharomyces boulardii (yeast) Probiotics and biofilms TW
  5. 5. Definition 5  Prebiotics- dietary substances (non digestible by human enzymes, non starch carbohydrates) e.g. inulin, lactulose, oligofructose  Stimulate favorable growth or activity of probiotic bacteria  Synbiotics (eubiotics)- Products that contain both probiotics and Prebiotics Probiotics and biofilms TW
  6. 6. Mechanism of action 6 Anti cancer effects Are shown to reduce concentration of carcinogenic chemicals (Scavenge superoxide radicals) Modify epithelial cell kinetics Probiotics and biofilms TW
  7. 7. Mechanism of action 7 Anti diarrheal effect Lowering GI pH Secreting bacteriocins Reconstruction of normal flora (especially antibiotics associated and radiation induced diarrhea) Competing for adhesion sites Probiotics and biofilms TW
  8. 8. Mechanism of action 8 Immunomodulation  Enhanced barrier  Increased mucus secretion  Epithelial membrane integrity  Activation Bacterial surface antigens  Suppression  Inducing T-reg cells  Inducing regulatory cytokines; TGF-β, IL-10 Counteract pro-inflammatory cytokines Probiotics and biofilms TW
  9. 9. Mechanism of action 9 Anti-allergy effects  Reducing antigenic challenge; by enhanced membrane integrity ( as most allergic reactions are thought as a result of large antigenic insult after barrier disintegrates)  Modification of allergen receptor Probiotics and biofilms TW
  10. 10. Mechanism of action 10  Stomach and Urogenital health  Inhibitory  An effect of lactic acid for H.pylori estimated reason for Urogenital health is maintenance of acidic environment (lactic acid) and production of other antibacterial chemicals (e.g. H2O2) Probiotics and biofilms TW
  11. 11. Other roles of Probiotics 11 Reduction of hypertension- by fermentation end products which have inhibitory effect on angiotensin I conversion Lowering blood cholesterol level Improvement in Ca absorption Production of some vitamins and digestive enzymes Probiotics and biofilms TW
  12. 12. Questions to be answered 12  Dose of the probiotic bacteria  For how long should it be taken  Correlation of specific probiotic species with its specific action and target Probiotics and biofilms TW
  13. 13. Summary 13 Probiotics and biofilms TW
  14. 14. Introduction 14  What are biofilms?  Why should we care about biofilms?  What makes them special?  What happens as a result of biofilms?  How they are formed?  How they are removed? Probiotics and biofilms TW
  15. 15. Introduction about biofilms 15  The concept of bacterial biofilm was proposed in 1936.  In natural aquatic environments bacteria are predominantly not free floating but grow as multi-species communities attached to submerged surfaces.  Over 90% of all bacteria live in biofilms.  In clinical medicine, many environments provide optimal conditions for the formation of bacterial biofilm, such as contact lenses, urinary catheters, and so on. Probiotics and biofilms TW
  16. 16. Introduction 16 What is Biofilm??  A biofilm is a community of microorganisms, attached to a wet or moist surface. Microorganisms include bacteria, yeasts, algae, fungi.  These microbes make a sticky, slimy, gel-like substance and surround themselves with it. Probiotics and biofilms TW
  17. 17. Bio film constitutes 17  A biofilm is an aggregate of microorganisms in which cells are stuck to each other and/or to a surface.  These adherent cells are frequently embedded within a self- produced matrix known as extracellular polymeric substance (EPS).  Biofilm EPS, which is also referred to as "slime," is a polymeric jumble of DNA, proteins and polysaccharides. Probiotics and biofilms TW
  18. 18. Bio film constitutes 18  Biofilms may form on living or non-living surfaces and can be prevalent in natural, industrial and hospital settings.  For example, a pebble in a pond is covered in slimy green stuff. That slime is a biofilm.  The slippery layer that builds up inside a waste pipe is a biofilm.  The plaque that builds up between the gum and the tooth is a biofilm. Probiotics and biofilms TW
  19. 19. Why Do Bacteria Make Biofilms? 19 Biofilms protect the pathogenic bacteria, making them hard to kill. Hiding in biofilms, bacteria can spread throughout the body. Large, sticky biofilms resist the attack of the immune system and antibiotics. Probiotics and biofilms TW
  20. 20. Formation and Development of Biofilms 20 • Biofilm formation is not a random process  Biofilms start as just a few bugs forming a thin layer.  They can develop into complex, three dimensional structures housing millions of individual bacterium.  Like miniature cities, they have towers, columns, bridges and channels for the flow of nutrients. Probiotics and biofilms TW
  21. 21. Formation and Development of Biofilms 21  What is the use of understanding the….? formation, composition, and characteristics of the biofilm assists in its control and for developing treatment strategies of biofilm diseases.  The greater our understanding of the processes involved in biofilm formation, the greater the chance of developing remedies. Probiotics and biofilms TW
  22. 22. Formation and Development of Biofilms 22  The pattern of biofilm formation can be divided into three phases: I. Attachment of bacteria to a solid surface; II. Formation of micro colonies on the surface; and III. Formation of the mature biofilms Probiotics and biofilms TW
  23. 23. Formation and Development of Biofilms 23  Neighbors in the biofilm work together to build their niche environment.  Some bugs use their bodies to build support structures, arches, columns.  Others form the foundation and are good at sticking onto the host surface.  Some make the sticky goo or slime that protects them. Probiotics and biofilms TW
  24. 24. Formation and Development of Biofilms 24  Formation of a biofilm begins with the attachment of free-floating microorganisms to a solid surface.  These first colonists adhere to the surface initially through weak, reversible adhesion via van der Waals forces.  If the colonists are not immediately separated from the surface, they can anchor themselves more permanently using cell adhesion structures such as pili. Probiotics and biofilms TW
  25. 25. Formation and Development of Biofilms 25  Once a bacterium attaches to a surface, it activates a whole different set of genes that gives the bacterium different characteristics from those that it had as a free-floating organism.  The first colonists facilitate the arrival of other cells by providing more diverse adhesion sites and beginning to build the matrix that holds the biofilm together.  Some species are not able to attach to a surface on their own but are often able to anchor themselves to the matrix or directly to earlier colonists.  It is during this colonization that the cells are able to communicate via quorum sensing. Probiotics and biofilms TW
  26. 26. Formation and Development of Biofilms 26  Once colonization has begun, the biofilm grows through a combination of cell division and recruitment of new bacteria.  Biofilm doubling times are rapid in early development and slower in more mature biofilms.  A second wave of bacterial colonizers adheres to bacteria that are already attached to the surface. Probiotics and biofilms TW
  27. 27. Formation and Development of Biofilms 27  The bacteria cluster together to form sessile, mushroom-shaped micro colonies that are attached to the surface at a narrow base.  Co aggregation is the ability of new bacterial colonizers to adhere to the attached cells.  The result of co aggregation is the formation of a complex array of different bacteria linked to one another. This is what we call it mature biofilm  Their Own Little World!!!! Probiotics and biofilms TW
  28. 28. Formation and Development of Biofilms 28 Microbes form a biofilm in response to many factors, which may include  cellular recognition of specific or nonspecific attachment sites on a surface,  nutritional cues, or  in some cases, by exposure of planktonic cells to sub-inhibitory concentrations of antibiotics. Probiotics and biofilms TW
  29. 29. Dispersal of biofilms 29  Dispersal of cells (bacteria) from the biofilm colony is an essential stage of the biofilm life cycle.  Dispersal enables biofilms to spread and colonize new surfaces.  Enzymes that degrade the biofilm extracellular matrix, such as dispersin B and deoxyribonuclease, may play a role in biofilm dispersal. Probiotics and biofilms TW
  30. 30. Probiotics and biofilms TW 30
  31. 31. Quorum sensing 31  To work together efficiently, the bugs need to talk to one another. They do so by chemical signals. Bacteria produce diffusible extracellular signalling molecules ( AHLs and oligopeptides)  Bacteria are often considered as simple unicellular organisms, but research has recently shown that many bacteria possess ability to communicate with one another and to organize to communal groups.  to monitor their own population density and to coordinate expression of specific sets of genes in response to the cell density.  This type of cell-density-dependent gene regulation is termed Quorum sensing. Probiotics and biofilms TW
  32. 32. Properties and structure of biofilms 32  Biofilms are surface-attached microbial communities with characteristic architecture and phenotypic and biochemical properties distinct from their planktonic counterparts.  One of the best-known of these biofilm specific properties is the development of antibiotic resistance  Biofilms are characterized by • structural heterogeneity, genetic diversity, complex community interactions, and an extracellular matrix of polymeric substances. Probiotics and biofilms TW
  33. 33. properties cont… 33 The structure of a biofilm community comprises bacterial A. Micro colonies, B. An extracellular slime layer, C. Fluid channels, and D. A primitive communication system. Probiotics and biofilms TW
  34. 34. properties cont… 34 A. Each micro colony is a tiny, independent community containing thousands of compatible bacteria.  Bacteria in the center --strict anaerobic environment, while other bacteria at the edges -aerobic environment.  Thus, the biofilm structure provides a range of customized living environments (with differing PHs, nutrient availability, and oxygen concentrations) within which bacteria with different physiological needs can survive. B. The extracellular slime layer is a protective barrier that surrounds the mushroom shaped bacterial microcolonies. Probiotics and biofilms TW
  35. 35. properties cont… 35  The slime layer protects the bacterial micro colonies from antibiotics, antimicrobials, and host defense mechanisms. C. A series of fluid channels penetrates the extracellular slime layer.  These fluid channels provide nutrients and oxygen for the bacterial micro colonies and facilitate movement of bacterial metabolites, waste products, and enzymes within the biofilm structure. D. Each bacterial micro colony uses chemical signals to create a primitive communication system used to communicate with other bacterial micro colonies. Probiotics and biofilms TW
  36. 36. 36 Depiction of the dynamic nature of a biofilm community. Probiotics and biofilms TW
  37. 37. USE AND PROBLEMS OF BIOFILMS 37 Benefits  Help remove pathogens and reduce the amount of organic matter in the water, and  Eliminate petroleum oil from contaminated oceans or marine systems. Problems  They are associated with persistent infections and  They are notorious for their pipe-clogging and corroding properties, a costly irritation in industrial settings.  Undesirable taste and odor issues in the water industry;  Pipe corrosion within oil and gas industries and souring of oil in pipelines and storage facilities.  Can make sanitation difficult in food preparation areas. Probiotics and biofilms TW
  38. 38. Biofilms and infectious diseases 38 • Biofilms have been found to be involved in a wide variety of microbial infections in the body.  It has taken longer to make a clear connection of biofilms to persistent infections in native tissue.  According to the CDC, 65% of all infections in developed countries are caused by biofilms  Biofilms are produced by most if not all pathogens. Probiotics and biofilms TW
  39. 39. Biofilms and cont… 39  A well known example of a microbial biofilm in human disease is dental plaque, which is the most known and studied biofilm (secreting acids that destroy teeth and gums).  Pseudomonas aeruginosa, causing an incurable infection in cystic fibrosis patients (Singh et al. 2000),  and Staphylococcus aureus and Staphylococcus epidermidis, infecting indwelling devices (Mack et al. 2004), are probably the best-known biofilm-producing organisms. Probiotics and biofilms TW
  40. 40. Biofilms and cont… 40  Biofilms are responsible for a significant portion of acute infections.  A classic case is that of Legionnaire’s disease, an acute respiratory infection resulting from aspiration of clumps of Legionella biofilms detached from air and water heating/cooling systems.  Many food borne pathogens such as E. coli 0157:H7, Listeria monocytogenes, Yersinia enterocolitica, Salmonella spp. and Camphylobacter jejuni can form either single-species or multi-species biofilms on food surfaces and equipment Probiotics and biofilms TW
  41. 41. Biofilms and cont… 41 Teeth with Dental Caries The term dental caries refers to the destruction, or necrosis, of teeth usually by bacterial action resulting in a condition commonly known as tooth decay. . Probiotics and biofilms TW
  42. 42. Examples of diseases associated with biofilm 42  Otitis media (middle ear infections)  Periodontal disease  Gingivitis  Dental Caries  Chronic bacterial prostatitis  Endocarditis  Sinusitis  UTI  Infections in cystic fibrosis  Infections of all known indwelling devices such as catheters, orthopedic prostheses, and heart valves; Probiotics and biofilms TW
  43. 43. Anti-microbial resistance of Biofilm 43  Bacteria within biofilms are up to 1000 times more resistant to antimicrobials than the same bacteria in suspension.  Extracellular matrix of the biofilm is a passive barrier for antibiotics  To protect the cells against the antibiotics tobramycin and gentamicin P. aeruginosa produces only in biofilms a periplasmic cyclic glucan which complexes antibiotics turning them into harmless compounds. Probiotics and biofilms TW
  44. 44. Anti-microbial resistance cont… 44  In biofilms up to 20% of all genes are differently expressed.  Bacteria in biofilms grow slower and with the reduced metabolic activity they are less prone against most antibiotics.  Preliminary evidence suggests that different bacteria within a biofilm can trade genes -- possibly including Abx resistance genes  The infections associated with biofilms may appear to respond to systemic antibiotics because planktonic cells respond and symptoms are reduced, but the persistence of adherent cells leads to recurrent episodes of infection. Probiotics and biofilms TW
  45. 45. Three hypotheses for mechanisms of antibiotic resistance in biofilms 45 Probiotics and biofilms TW
  46. 46. Prevention and control of biofilm 46  An effective mechanical control mechanism is biofilm detachment.  Interfere with the bacterial cell to cell communication  A novel alternative to antibiotics are Probiotics.  A unique spray made from stabilized enzymes that can readily dissolve the biofilms. Probiotics and biofilms TW
  47. 47. Conclusion and recommendation 47  Biofilms, once considered odd curiosity, are now one of the hottest topics in microbiology. Biofilms occur everywhere: dental plaque is one the most common biofilms that decay teeth,  other biofilms can clog water pipes, others can contaminate  almost any medical device inserted into the body, ranging from contact lenses to catheters and artificial hearts.  Microbiologists have traditionally researched only freefloating, individual bacteria growing in laboratory cultures.“Microbiologists have been barking up the wrong tree since the time of Pasteur,” says Costerton. Probiotics and biofilms TW