Bacteriology week3-4

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  • 1.BACTERIOLOGI5/03/2012 Masdiana Padaga 1

2. Bacteria on Earth Bacteria are in every environment imaginable!5/03/2012 Masdiana Padaga2 3. Size 5/03/2012Fig. 2-5 Six Comparisons Among Various Living Things and Molecules 3 Masdiana Padaga 4. Rod-Shaped Bacteria 5. Spherical Bacteria 6. Spirochete:Borrelia burgdorferi Spiral-Shaped Bacteria 7. Bacterial Morphology5/03/2012 Masdiana Padaga 7 8. Bacterial Anatomy (Overview)5/03/2012Masdiana Padaga8 9. Prokaryotic Cells Means before a nucleus Domains Bacteria and Archaea Can live in environmental extremes Live off diverse energy sources5/03/2012 Masdiana Padaga9http://micro.magnet.fsu.edu/cells/bacteriacell.html http://www.daviddarling.info/encyclopedia/P/prokaryoticcell.h 10. ProkaryoticStructures Cytoplasm A liquid material thatparticles are suspended in Ribosomes Site of protein synthesis Located in cytoplasm Nucleoid Contains hereditarymaterial (DNA) of thecell Located in cytoplasm 5/03/2012Masdiana Padaga 10 11. ProkaryoticStructuresPlasma membrane Encloses the cell Regulates material intoand out of cell Cell Wall Supports cell anddetermines its shape Capsule Slime layer Protects Helps to not dry out Helps attach to othercells5/03/2012 Masdiana Padaga 11 12. ProkaryoticStructures Flagella Used to swim/move Spins like a propeller or whip like Pilli Hair or threadlike structures Help stick to other cells for mating or animal cells for food and protection 5/03/2012Masdiana Padaga 12 13. Cytoplasm Composed largely of water, together with proteins, nucleicacid, lipids and small amount of sugars and salts R ib os om e s : numerous, 15-20nm in diameter with 70S;distributed throughout the cytoplasm; sensitive tostreptomycin and erythromycin site of protein synthesis P las m id s : extrachromosomal genetic elements Inclu s ions : sources of stored energy, e,g volutin 14. Plasmid Plasmidsaresmall circular/line extrachromosomal double-stranded DNA molecules capable of self-replication and contain genesthat confer some properties such as antibioticresistance virulence.InclusionsInclusions of are aggregates of various compoundsBacteria that are normallyg ra nulo sinvolved in storing energy reserves or e building blocks for the cell. accumilate when a cell is grown in the presence of excess nutrients 15. Cellmembrane Site of biosynthesis of DNA, cell wall polymers andmembrane lipids. Selective permeability and transport ofsolutes into cells Electron transport and oxidative phosphorylation Excretion of hydrolytic exoenzymes 16. Nucleus Lacking nuclearmembrane, absenceof nucleoli, henceknown as nucleicmaterial or nucleoid,one to several perbacterium. 17. Prokaryotic Cell Structure Glycocalyx - term to describesubstances that surround bacterialcells 1. Capsule if substance is organized and firmlyattached to cell wall 2. Slime Layer if substance is unorganized and looselyattached to cell wall5/03/2012 Masdiana Padaga17 18. Capsules and slime layers Attachment Protection from phagocytic engulfment. Resistance to drying. Depot for waste products. Reservoir for certain nutrients. protection These are structures surrounding the outside of the cell envelope. Theyusually consist of polysaccharide; however, in certain bacilli they arecomposed of a polypeptide (polyglutamic acid). Capsules are often lostduring in vitro culture.5/03/2012 Masdiana Padaga18 19. Flagella: Polar monotrichousPolar amphitrichous SpirilliumLophotrichous Pseudomonas SpirillumPeritrichousSalmonellaSEM of peritrichous strain ProteousNote: bacteria without flagella are called atrichous. 5/03/2012 Masdiana Padaga 19 20. In Gram-negative Bacteria5/03/2012 Masdiana Padaga 20 21. In Gram-positive Bacteria5/03/2012Masdiana Padaga 21 22. Motility Flagella consist of a Almost all Spiral bacteria arenumber of proteinsmotile About 1/2 of Bacilli areincluding flagellin motile Identification of Almost all Cocci are non-motileBacteria Bacteria move toward Pathogenesisattractive stimuli and awayfrom harmful substances Motility of bacteriaand waste products in theprocess known as chemotaxis.5/03/2012 Masdiana Padaga22 23. 5/03/2012 Masdiana Padaga 23 24. Pilli or fimbrae Filamentous appendages that areshorter, straighter and more numerousthat flagella Conjugation pilli found in certain groupof bacteria. Used for genetic material transfer. The transfer process is calledconjugation. Antibiotic resistance transfer. Atatchment pilli, Help bacteria adhareto the surfaces, such as cell surfacesand interface of water and air. It helps in colonization andpathogenicity. found mostly in Gram (-) Bacteria5/03/2012 Masdiana Padaga24 25. E. coli (pathogenic)5/03/2012 Masdiana Padaga 25 26. Cell Wall Main structural component -Peptidoglycan Peptidoglycan repeating dissacharide units polypeptides 5/03/2012Masdiana Padaga 26 27. Gram-Positive Gram- Negative Peptidoglycan PeptidoglycanCell MembraneMembrane Outer MembranePeriplasmPeptidoglycanCytoplasmicPeptidoglycan membranePeriplasmic spaceAnothercell5/03/2012Masdiana Padaga 27 28. Bacterial Cell Walls 5/03/2012 Masdiana Padaga 28 29. Gram (+) Cell Wall NAMN-acetylmuramic acid NAG N- acetylglucosamine tetrapeptide side chains pentaglycine crossbridges teichoic acid 5/03/2012 Masdiana Padaga 29 30. Gram (-) Cell Wall NAM NAG Tetrapeptide side chains pentaglycine 2nd Outer membrane Lipopolysaccharides (LPS) Lipid A O Antigen5/03/2012 Masdiana Padaga 30 31. Functions of Cell Wall Maintaining the cells characteristic shape- the rigidwall compensates for the flexibility of thephospholipid membrane and keeps the cell fromassuming a spherical shape Countering the effects of osmotic pressure Providing attachment sites for bacteriophages Providing a rigid platform for surface appendages-flagella, fimbriae, and pili all emanate from the walland extend beyond it Play an essential role in cell division Be the sites of major antigenic determinants of thecell surface Resistance of Antibiotics 5/03/2012 Masdiana Padaga31 32. Cell Membrane (Plasma Membrane) 2 structural component double layer of phospholipids proteins Fluid Mosaic Model 5/03/2012Masdiana Padaga 32 33. cytoplasmic membrane5/03/2012 Masdiana Padaga 33 34. 5/03/2012 Masdiana Padaga 34 35. Functions of Cell Membrane 1. Selective barrier (selectivelypermeable) 2. Secretes exoenzymes amylases lipases peptidases CAN NOT UNDERGO PHAGOCYTOSIS5/03/2012Masdiana Padaga35 36. Functions of CellMembrane 3. E.T.S. is located here 4. Enzymes for cell wall synthesis 5. If photosynthesis, enzymes arelocated on membranous structurescalled thylakoids 6. Mesosomes - invagination of cellmembrane attached to DNA (Binary Fission)? 5/03/2012Masdiana Padaga 36 37. Endospores Identification of Bacteria (spores) Pathogenesis Resistance Dormant cell Resistant to adverseconditions Produced when starved- high temperatures Contain calcium dipicolinate- organic solvents DPA, Dipicolinic acid5/03/2012 Masdiana Padaga and Clostridium37Bacillus 38. MethodMicroscope Light Microscope Electron Microscope Darkfield Microscope Phase ContrastMicroscope Fluorescence Microscope Confocal Microscope Staining Methods Simple staining; Differentialstaining(Gramstain, Acid-fast stain), Special staining( Negative stain, 5/03/2012Spore stain, Flagella stain) 38 Masdiana Padaga 39. 5/03/2012 Masdiana Padaga 39 40. Gram Stain 1884 Hans Christian Gram most important stain used inBacteriology Divides all Bacteria into 2 groups: Gram (+) Gram (-) 5/03/2012Masdiana Padaga 40 41. Gram Staining5/03/2012Masdiana Padaga 41 42. Results Gram (+) Purple Gram (-) Red Difference - due tostructure of cell wall Gram (+) Thick cell wall Gram (-) Thin cell wall 5/03/2012Masdiana Padaga 42