My PPT_Quorum Sensing Controlling Biofil

Quorum talk In Biofilms : 

Quorum talk In Biofilms Understanding the Microbial Language for Colonization By: B.Samuel Raj M. Sc. Applied Microbiology, SBCBE, VIT.

What is Quorum Sensing? : 

What is Quorum Sensing? An intercellular signaling process by which bacteria produce and respond to chemical cues in many cases to monitor population density (Danhorn, T. and C. Fuqua. 2007) Quorum sensing is a process of chemical communication that bacteria use to assess cell population density and synchronize behavior on a community-wide scale. Communication is mediated by signal molecules called autoinducers. (Xavier K. B 2007)

The Components in QS: : 

The Components in QS: The Genes I gene: R gene: The gene products LuxI - Autoinducer1: Acyl-Homoserine Lactone LuxS - Autoinducer2: Furanosyl Borate Diester Cyclic Di-Peptides (M.T. Holden et al 1999)

QS Mechanisms : 

QS Mechanisms K. Winzer, K.H. Hardie and P. Williams P. Williams, et al.(2007) Look Who's Talking: Communication And Quorum Sensing In The Bacterial World Phil. Tran. Biol. Sc., 362.

What is Biofilm? : 

What is Biofilm? J.W. Costerton, Montana State University,USA (Scientific American, 1978) A biofilm is a complex aggregation of microorganisms marked by the excretion of a protective and adhesive matrix (EPS).

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channels exist for the circulation of nutrients and water (Costerton et al., 1999; Watnick and Kolter, 2000)

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Confocal laser scanning microscopy of hollow P. aeruginosa biofilm cell clusters. Biofilms were grown in glass capillary tubes under continuous flow. The bacteria contained green fluorescent protein and appeared green. The specimen was counterstained with rhodamine B (red), the primary utility of which was in locating the glass wall. Shown are two different locations of the same specimen. Hunt, S. M., E. M. Werner, B. Huang, M. A. Hamilton, and P. S. Stewart. 2004. Hypothesis for the role of nutrient starvation in biofilm detachment. Appl. Environ. Microbiol. 70:7418-7425. doi: 10.1128/AEM.70.12.7418-7425.2004.

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In the cartoon above, various species of bacteria are represented by different colors. Bacteria can produce chemical signals ("talk") and other bacteria can respond to them ("listen") in a process commonly known as cell-cell communication or cell-cell signaling. This communication can result in coordinated behavior of microbial populations. Courtesy, Montana State University-Center for Biofilm Engineering.

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Source: http://ares.jsc.nasa.gov/astrobiology/biomarkers/_images/biofilm.jpg

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Time zero After 2 days of water flow over the glass slide Characteristic morphology of microbial cells found on the surface of glass slides after 2 days using scanning electron  microscopy (5000x) Source: http://www.ul.ie/elements/Issue7/Biofilm%20Information.htm

How do Biofilms form? : 

How do Biofilms form? Three step process Reversible attachment Where the cell adher to the surface Irreversible Attachment Where the cells bind to the surface with pili Development Qs, reproduction, EPS and community regulation Maturation And Dispersion

Reversible Attachment : 

Reversible Attachment The Cell settlement Converting from Flagella form into Pili form i.e. gene switiching involving QS (

Irreversible Attachment : 

Irreversible Attachment Adhering to the surface with pili The Initiation of Signaling Production of ExoPolySaccharide or Extracellular polymeric substance

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Source: Freshwater

Development : 

Development Crossing the Signaling thershold The reproduction High production of EPS Community regulation

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Source: Stoodley et. al. 2002. Biofilms as Complex Differentiated Communities. Annu. Rev. Microbiol. 56:187–209

Maturation and Dispersion : 

Maturation and Dispersion

QS importance in biofilm : 

QS importance in biofilm Rice, S. A., et. al. J. Bacteriol. 2005

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Source: David C. Sigee (ed.), Freshwater Microbiology: Biodiversity and Dynamic Interactions of Microorganisms in the Aquatic Environment, John Wiley & Sons, Ltd., 2005

Pathogenic Biofilm : 

Pathogenic Biofilm A new model of the infectious cycle of V. cholerae makes sense of unexpected findings about their quorum-sensing behavior. Quorum-sensing works at two stages, propose Jun Zhu and John Mekalanos, first to limit the protective biofilm so they can survive the stomach but break away in the gut, and then to break away from the gut and back into the environment. Source: http://focus.hms.harvard.edu/2003/Nov21_2003/microbiology.html

Biofilm Ecology : 

Biofilm Ecology Source: David C. Sigee (ed.), Freshwater Microbiology: Biodiversity and Dynamic Interactions of Microorganisms in the Aquatic Environment, John Wiley & Sons, Ltd., 2005

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Source: David C. Sigee (ed.), Freshwater Microbiology: Biodiversity and Dynamic Interactions of Microorganisms in the Aquatic Environment, John Wiley & Sons, Ltd., 2005

Their Properties: : 

Their Properties: 15% bacterial cells and 85% EPS This matrix is strong enough that under certain conditions, biofilms can become fossilized. They Protect the community from the harsh environment, ex toxins, clorination or antibiotics They act as separate ecosystem Varies with species

Biofilm Habitat : 

Biofilm Habitat Biofilms are ubiquitous Soil, Nodules, termite, rumen etc. Fresh and Marine waters Rocks and pebbles at the bottom of most streams Hot Acidic Yellow Stone National Park Industrial Pipelines Sewage Treatment plants Teeth, Endocarditis, Otitis media, Urinary catheter etc

Biofilm: A Bad agent : 

Biofilm: A Bad agent Protective capability for Bacteria – Resistance High viscosity (low washout rate) –Hard to remove present on the teeth clogging and corrosion Slippery (Costerton 1978) Pitting corrosion on 316S stainless steel, an example of microbially influenced corrosion. Image, courtesy of Z. Lewandowski and W. Dickinson, MSU-CBE   Pasted from <http://www.cs.montana.edu/ross/personal/intro-biofilms-s4.htm> (Borenstein et. al. 1994)

Biofilm: A good Agent : 

Biofilm: A good Agent Food for Organisms like Fishes Survival Strategy for the Microbes Eliminating petroleum oil from contaminated oceans or marine systems Sewage treatment plants – Trickling Filter Soil Aggregation – Soil formation Slippery (Costerton 1978) – Leading its Identification

Techniques to study biofilm : 

Techniques to study biofilm Metagenomic analysis Microscopy Culture based techniques And other Non Culture Based Techniques

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C. Schmeisser, Metagenome Survey of Biofilms in Drinking-Water Networks. App. Environ. Microb., (2003)

To remove: : 

To remove: No stagnant water Proper washing and chlorination Quorum Quenchers Anti-Bacterial-Biofilm Lactoferrin Xylitol Biocides Antibiotics

Conclusion : 

Conclusion They are Ubiquitous Water is a main cause of spread Quorum is necessary for biofilm formation Can be both Beneficial and harmful Resent studies show that they can be controlled but still it cant be removed completely Internal metabolism is not properly understood

ReferenceS : 

ReferenceS Borenstein S (1994) Microbiologically influenced corrosion handbook. Industrial Press, New York Chen X, Schauder S, Potier N, Van Dorsselaer A, Pelczer I, Bassler BL, Hughson FM. (2002)Structural identification of a bacterial quorum-sensing signal containing boron. Nature 415: 545–549. Costerton J W. (1978) How bacteria stick. Sci. Amer. 238:86-95. Costerton, J.W., Stewart, P.S., and Greenberg, E.P. (1999) Bacterial biofilms: a common cause of persistent infections. Science 284: 1318–1322 Danhorn, T. and C. Fuqua. (2007) Biofilm formation by plant-associated bacteria. Annu. Rev. Microbiol. 61:401-422. David C. Sigee (ed.), Freshwater Microbiology: Biodiversity and Dynamic Interactions of Microorganisms in the Aquatic Environment, John Wiley & Sons, Ltd., Chichester, United Kingdom, 2005, 524 p Fuqua, W. C., Winans, S. C. & Greenberg, E. P. (1994) Quorum sensing in bacteria: The LuxR-LuxI family of cell density-responsive transcriptional Regulators J. Bacteriol. 176, 269-275 Holden, M. T. G. et al. (1999) Quorum-sensing cross talk: isolation and chemical characterization of cyclic dipeptides from Pseudomonas aeruginosa and other Gram negative bacteria. Mol. Microbiol. 33, 1254–1266. Hunt, S. M., E. M. Werner, B. Huang, M. A. Hamilton, and P. S. Stewart. (2004). Hypothesis for the role of nutrient starvation in biofilm detachment. Appl. Environ. Microbiol. 70:7418-7425. K. Winzer et al., (2002) LuxS: its role in central metabolism and the in vitro synthesis of 4-hydroxy-5-methyl-3(2H)-furanone, Microbiology 148, pp. 909–922. K. Winzer, K.H. Hardie and P. Williams. (2002) Bacterial cell-to-cell communication: sorry, can’t talk now go to lunch! Curr. Opin. Microbiol.5: 216-222 Kaneko Y, Thoendel M, Olakanmi O et al. (2007) The transition metal galllium disrupts pseudomonas aeruginosa iron metabolism and has antimicrobial and antibiofilm activity. J. Clin Invst. Klausen, M., Heydorn, A., Ragas, P., Lambertsen, L., Aaes-Jorgensen, A., Molin, S. & Tolker-Nielsen, T. (2003) Biofilm formation by Pseudomonas aeruginosa wild type, flagella and type IV pili mutants. Mol. Microbiol. 48, 1511–1524. P. Williams, K. Winzer, W. C. Chan, M. Cámara,(2007) Look Who's Talking: Communication And Quorum Sensing In The Bacterial World Phil. Tran. Biol. Sc., 362, 1119–1134. Pauline P. Ward, Sonia Uribe-Luna, and Orla M. Conneely (2002) Lactoferrin and host defense Biochem. Cell Biol. 80: 95–102 . Rice, S. A., K. S. Koh, S. Y. Queck, M. Labbate, K. W. Lam, and S. Kjelleberg. (2005) Biofilm formation and sloughing in Serratia marcescens are controlled by quorum sensing and nutrient cues. J. Bacteriol. 187:3477-3485. S. Schauder et al., (2001), The LuxS family of bacterial autoinducers: biosynthesis of a novel quorum-sensing signal molecule, Mol. Microbiol. 41 463–476. Watnick, P and Kolter, R. (2000) Biofilm, city of microbes. J Bacteriol 182: 2675–2679. Xavier, K. B., S. T. Miller, W. Lu, J. H. Kim, J. Rabinowitz, I. Pelczer, M. F. Semmelhack, and B. L. Bassler. (2007) Phosphorylation and processing of the quorum sensing molecule autoinducer-2 in enteric bacteria. ACS Chem. Biol. 2:128-136.

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