BIOFILMS.pptx by Dr. Advaitha Anand MDS

this seminar explains about dental biofilms

1. BIOFILMS Dr.Advaitha Anand M.D.S 2 nd Year

2. INTRODUCTION Biofilm is defined as a community of microcolonies of microorganism in an aqueous solution that is surrounded by a matrix made of glycocalyx, which also attaches the bacterial cells to a solid substratum. – Grossman Biofilm is a mode of microbial growth where dynamic communities of interacting sessile cells are irreversibly attached to a solid substrate, as well as each other, and are embedded in a self made matrix of extracellular polymeric substance – Ingle

3. Basic Criteria for a Biofilm According to Caldwell et al. , a biofilm has the following attributes: Autopoiesis : Ability to self-organize Homeostasis : Ability to resist environmental disturbances. Synergy : Synergy is the property of an organism to give better results when working together i.e. it must be more effective in association with fellow microorganisms than in isolation Communality : Respond to environmental challenges as a combined unit rather than as single individuals. Pathways of the Pulp : Cohen : 11th Edition 2015

4. Biofilms are characterized by Surface attachment Extracellular matrix of polymeric substances Structural heterogenicity Genetic diversity Complex community interactions Pathways of the Pulp : Cohen : 11th Edition 2015

5. ULTRASTRUCTURE OF A BIOFILM INGLE’S ENDODONTICS 6 TH EDITION 2008

6. COMPOSITION INGLE’S ENDODONTICS 6 TH EDITION 2008

7. Viable, fully hydrated biofilm appears as ‘tower’ or ‘mushroom’ shaped structure adherent to the substrate . Water channels : regarded as circulatory system in a biofilm : establish connection between microcolonies. Facilitates efficient exchange of materials between bacterial cells and bulk fluid Coordinate functions in a biofilm community. INGLE’S ENDODONTICS 6 TH EDITION 2008

8. MATRIX A glycocalyx matrix made up of extracellular polymeric substance (EPS) surrounds the microcolonies and anchors the bacterial cell to the substrate. Functions: Maintains the integrity of biofilms Prevents dessication Resists antimicrobial agents Create a nutritionally rich environment Acts as a buffer and retains extracellular enzymes Pathways of the Pulp : Cohen : 11th Edition 2015

9. Pathways of the Pulp : Cohen : 11th Edition 2015

10. Pathways of the Pulp : Cohen : 11th Edition 2015

11. CHARACTERISTICS OF BIOFILM Donlan RM. Biofilms: microbial life on surfaces.  Emerg Infect Dis. 2002;8(9):881-890. doi:10.3201/eid0809.020063

12. DEVELOPMENT OF A BIOFILM

13. DEVELOPMENT OF A BIOFILM Bacteria can form biofilm on any surface that is bathed in a nutrition containing fluid. 3 major components involved in biofilm formation Bacterial cells A solid surface A fluid medium Influenced by the physicochemical properties of the components involved in the biofilm Donlan RM. Biofilms: microbial life on surfaces.  Emerg Infect Dis. 2002;8(9):881-890. doi:10.3201/eid0809.020063

14. STAGE 1 Adsorption of inorganic and organic molecules to the solid surface, forming a thin layer termed as conditioning layer. During dental plaque formation, the tooth surface is conditioned by the saliva pellicle. Pseudomonas Aeruginosa Biofilm: Role of Exopolysaccharides in the Function and Architecture of the Biofilm 0.14737/jimb.2307-5465/2.4.61.73 Journal of Infection and Molecular Biology 2014

15. STAGE 2  Adhesion of microbial cells to this layer. Phase 1 - Transport of microbes to surface. Phase 2 - Initial non specific microbial-substrate adherence phase. Phase 3 - Specific microbial-substrate adherence phase. Pioneer organisms : streptococci (major population) Pseudomonas Aeruginosa Biofilm: Role of Exopolysaccharides in the Function and Architecture of the Biofilm 0.14737/jimb.2307-5465/2.4.61.73 Journal of Infection and Molecular Biology 2014

16. Several factors that affect bacterial attachment to a solid substrate.

17. Bridges formed are a combination of Electrostatic attraction Covalent and hydrogen bonding Dipole interaction Hydrophobic interaction Bacteria with surface structures: P. gingivalis , S. mitis, Streptococcus salivarius , P. intermedia, P. nigrescens , S. mutans and A. naeslundii . Pseudomonas Aeruginosa Biofilm: Role of Exopolysaccharides in the Function and Architecture of the Biofilm 0.14737/jimb.2307-5465/2.4.61.73 Journal of Infection and Molecular Biology 2014

18.  STAGE 3

19. A mature biofilm will be a metabolically active community of microorganisms where individuals share duties and benefits. Some microorganisms help in adhering to the solid support, while some others create bridges between different species The bacterial cells in a matured biofilm will exhibit considerable variation in its genetic and biochemical constitutions compared to its planktonic counterparts.

20. Two types of microbial interactions occur at the cellular level Co-adhesion : The process of recognition between a suspended cell and a cell already attached to substratum. Co-Aggregation :Genetically distinct cells in suspension recognize each other and clump together

21. STAGE 4 : Detachment / Dispersion

22. Quorum sensing Miller MB, Bassler BL. Quorum sensing in bacteria. Annu Rev Microbiol . 2001;55:165-99. doi : 10.1146/annurev.micro.55.1.165. PMID: 11544353

23. Quorum sensing is involved in the regulation of Miller MB, Bassler BL. Quorum sensing in bacteria. Annu Rev Microbiol . 2001;55:165-99. doi : 10.1146/annurev.micro.55.1.165. PMID: 11544353 .

24. Resistance of Microbes in the Biofilm to Antimicrobials The nature of biofilm structure and physiological characteristics of resident microorganisms offer an inherent resistance to antimicrobial agents, such as antibiotics, disinfectants, or germicides. Mechanism responsible for resistance: Resistance associated with extracellular polymeric matrix. Resistance associated with growth rate and nutrient availability. Resistance associated with adoption of resistance phenotype.

25. Benefits Of Biofilm To Microbes Helps the bacteria to survive in unfavorable environmental and nutritional conditions. Resistance to antimicrobial agents. Increase in local concentration of nutrients. Opportunity of genetic material exchange. Ability to communicate between bacterial population of same and or different species. Produce growth factors across species boundaries.

26. ORAL BIOFILMS  Oral bacteria have the capacity to form biofilms on distinct surfaces ranging from hard to soft tissues. Oral biofilms are formed in three basic steps : Pellicle formation Bacterial colonization Biofilm maturation Berger, D., Rakhamimova , A., Pollack, A., & Loewy, Z. (2018). Oral Biofilms: Development, Control, and Analysis. High-throughput, 7(3), 24. https://doi.org/10.3390/ht7030024

27. Composition Water : 80% Inorganic and Organic : 20% Organic : Carbohydrates, proteins, and lipids. Inorganic : Calcium, phosphorus, magnesium and fluoride. Berger, D., Rakhamimova , A., Pollack, A., & Loewy, Z. (2018). Oral Biofilms: Development, Control, and Analysis. High-throughput, 7(3), 24. https://doi.org/10.3390/ht7030024

28. Carbohydrates : produced by bacteria : glucans, fructans , or levans . Contribute to the adherence of microorganisms to each other and are the stored form of energy in biofilm bacteria. Proteins (supragingival biofilm) : derived from saliva Proteins (subgingival biofilm) : derived from gingival sulcular fluid. Lipid : Endotoxins (LPS) from Gram-negative bacteria. Berger, D., Rakhamimova , A., Pollack, A., & Loewy, Z. (2018). Oral Biofilms: Development, Control, and Analysis. High-throughput, 7(3), 24. https://doi.org/10.3390/ht7030024

29. Berger, D., Rakhamimova , A., Pollack, A., & Loewy, Z. (2018). Oral Biofilms: Development, Control, and Analysis. High-throughput, 7(3), 24. https://doi.org/10.3390/ht7030024

30. Acquired Pellicle attracts Gram-positive cocci (S. mutans and S. sanguis : pioneer organisms) Filamentous bacterium (F. nucleatum and slender rods) adheres to primary colonizers. Gradually, the filamentous form grows into the cocci layer and replaces many of the cocci. Vibrios and spirochetes appear as the biofilm thickens. Berger, D., Rakhamimova , A., Pollack, A., & Loewy, Z. (2018). Oral Biofilms: Development, Control, and Analysis. High-throughput, 7(3), 24. https://doi.org/10.3390/ht7030024

31. Endodontic disease is a biofilm-mediated infection, and primary aim in the management of endodontic disease is the elimination of bacterial biofilm from the root canal system. The most common endodontic infection is caused by the surface-associated growth of microorganisms. Successful treatment of these diseases depends on biofilm removal as well as effective killing of biofilm bacteria. ENDODONTIC BIOFILM Jhajharia K, Parolia A, Shetty KV, Mehta LK. Biofilm in endodontics: A review. J Int Soc Prev Community Dent. 2015;5(1):1-12. doi:10.4103/2231-0762.151956

32. ENDODONTIC BIOFILM Less diverse compared to the oral microbiota Progression of infection alters the nutritional and environmental status within the root canal. Root canal environment has more anaerobic and depleted nutritional levels. Bacterial activities not confined to intracanal spaces, but also beyond the apical foramen. Jhajharia K, Parolia A, Shetty KV, Mehta LK. Biofilm in endodontics: A review. J Int Soc Prev Community Dent. 2015;5(1):1-12. doi:10.4103/2231-0762.151956

33. The development of  E. faecalis  biofilm on the root canal dentin involves three stages as follows: Jhajharia K, Parolia A, Shetty KV, Mehta LK. Biofilm in endodontics: A review. J Int Soc Prev Community Dent. 2015;5(1):1-12. doi:10.4103/2231-0762.151956

34. ENDODONTIC BIOFILM FORMATION MECHANISM there is penetration of the organism in the pulp where it attaches and spreads further along the root canal. it is after biofilm formation that the infectious process gains sufficient power to cause subsequent destruction of the pulpal tissue. a steady state is reached where the bacterial mass is held up by host defense mechanisms. The demarcation zone may be inside the root canal near the root canal exit at the foramen Jhajharia K, Parolia A, Shetty KV, Mehta LK. Biofilm in endodontics: A review. J Int Soc Prev Community Dent. 2015;5(1):1-12. doi:10.4103/2231-0762.151956

35. Classification of endodontic biofilms Intracanal microbial biofilms Extra radicular microbial biofilms Periapical microbial biofilms Biomaterial centered infections

36. Intracanal microbial biofilms Jhajharia K, Parolia A, Shetty KV, Mehta LK. Biofilm in endodontics: A review. J Int Soc Prev Community Dent. 2015;5(1):1-12. doi:10.4103/2231-0762.151956

37. Nutrient-rich condition after 4 week Nutrient-deprived condition after 1 week Nutrient-rich condition after 1 week Nutrient-deprived condition after 4 week

38. EXTRA-RADICULAR BIOFILM Biofilms formed on the root (cementum) surface adjacent to the root apex of endodontically infected teeth. Reported in Asymptomatic periapical periodontitis Chronic apical abscesses associated with sinus tracts. Cocci and short rods, with cocci attached to the tooth substrate. Filamentous and fibrillar forms were also observed in the biofilm. Calcified biofilms was also reported by Riccuci et al. Jhajharia K, Parolia A, Shetty KV, Mehta LK. Biofilm in endodontics: A review. J Int Soc Prev Community Dent. 2015;5(1):1-12. doi:10.4103/2231-0762.151956

39. PERIAPICAL MICROBIAL BIOFILMS Isolated biofilms found in the periapical region of an endodontically infected teeth. May or may not be dependent on the root canal. Actinomyces and P. propionicum : Asymptomatic periapical lesions Ability to overcome host defense mechanisms, thrive in the inflamed periapical tissue, and subsequently induce a periapical infection. Jhajharia K, Parolia A, Shetty KV, Mehta LK. Biofilm in endodontics: A review. J Int Soc Prev Community Dent. 2015;5(1):1-12. doi:10.4103/2231-0762.151956

40. BIOMATERIAL-CENTERED INFECTION (BCI) Jhajharia K, Parolia A, Shetty KV, Mehta LK. Biofilm in endodontics: A review. J Int Soc Prev Community Dent. 2015;5(1):1-12. doi:10.4103/2231-0762.151956

41. Bacterial adherence to a biomaterial surface is also described in three phases: Phase 1: Transport of bacteria to biomaterial surface, Phase 2: Initial non-specific adhesion phase, and Phase 3: Specific adhesion phase. Concise review of mechanisms of bacterial adhesion to biomaterial surfaces.An YH, Friedman RJ J Biomed Mater Res. 1998 Fall; 43(3):338-48.

42. ROLE OF  E. FEACALIS  IN BIOFILM E. faecalis  is a gram-positive, facultative anaerobic coccus that is strongly associated with endodontic infections. Being an opportunistic pathogen, it causes nosocomial infections and is frequently isolated from the failed root canals undergoing retreatment. E. faecalis  has the ability to form biofilm that can resist calcium hydroxide dressing by maintaining pH homeostasis, but at a pH of 11.5 or greater,  E. faecalis  is unable to survive. Jhajharia K, Parolia A, Shetty KV, Mehta LK. Biofilm in endodontics: A review. J Int Soc Prev Community Dent. 2015;5(1):1-12. doi:10.4103/2231-0762.151956

43. CURRENT THREUPATIC OPTIONS FOR ENDODONTIC BIOFILM Jhajharia K, Parolia A, Shetty KV, Mehta LK. Biofilm in endodontics: A review. J Int Soc Prev Community Dent. 2015;5(1):1-12. doi:10.4103/2231-0762.151956

44. CONCLUSION The most common endodontic infection is caused by the surface-associated growth of microorganisms. It is important to apply the biofilm concept to endodontic microbiology to understand the pathogenic potential of the root canal microbiota as well as to form the basis for new approaches for disinfection. It is foremost to understand that how the biofilm formed by root canal bacteria resists endodontic treatment measures

45. REFERENCES Pathways of the Pulp : Cohen : 11th Edition 2015 INGLE’S ENDODONTICS 6 TH EDITION 2008 Donlan RM. Biofilms: microbial life on surfaces.  Emerg Infect Dis. 2002; Jhajharia K, Parolia A, Shetty KV, Mehta LK. Biofilm in endodontics: A review. J Int Soc Prev Community Dent. 2015;5(1):1-12. doi:10.4103/2231-0762.151956 Concise review of mechanisms of bacterial adhesion to biomaterial surfaces.An YH, Friedman RJ J Biomed Mater Res. 1998 Fall; 43(3):338-48. Berger, D., Rakhamimova , A., Pollack, A., & Loewy, Z. (2018). Oral Biofilms: Development, Control, and Analysis. High-throughput, 7(3), 24. https://doi.org/10.3390/ht7030024