1 basic characters of bacteria
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1 basic characters of bacteria
- 1. Basic Characters of Bacteria Hope Tan
- 2. Size and ShapesSize and Shapes Size:Size: Unit for measurementUnit for measurement :: Micron orMicron or micrometer, μm: 1μm=10micrometer, μm: 1μm=10-3-3 mmmm
- 3. coccus bacillus Spiral bacterium Basic shapes of batcteriaBasic shapes of batcteria
- 4. Cocci: sphere, 1μm Bacilli: rods , 0.5 ～ 1 μm in width, 1~3 μm in length Spiral bacteria: 1~3 μm in length and 0.3~ 0.6 μm in width
- 5. CoccusCoccus S. Pneumoniae N. gonorrhoeae Streptococci Tetrads Sarcina Staphylococcus
- 6. Bacillus S. typhi B. abortus C. diphtheriae C. Botulinum M. tuberculosis B. anthracis
- 8. Basic structures Cell wall Cell membrane Cytoplasm Nuclear material Special structures Capsule Spore Flagella Pili Structure of bacteriaStructure of bacteria
- 9. Basic structure of bacteriaBasic structure of bacteria
- 10. 1. Chemical composition ： A. Common component—— peptidoglycan Also called mucopeptide or glycopeptide or murein Cell wallCell wall
- 11. • A backbone of N-acetyl glucosamine and N-A backbone of N-acetyl glucosamine and N- acetyl muramic acid: Both discovered inacetyl muramic acid: Both discovered in GG++ and Gand G-- bacteria.bacteria. • A set of identical tetrapeptide side chainA set of identical tetrapeptide side chain attached to N-acetyl-muramic acid: differentattached to N-acetyl-muramic acid: different components and binding modes in Gcomponents and binding modes in G++ and Gand G-- bacteria.bacteria. • A set of identical peptide cross bridges: onlyA set of identical peptide cross bridges: only in Gin G++ bacteriabacteria peptidoglycan
- 12. N – acetyl-gulcosamine N – acetyl-muramic acid β-1,4 glucosidic bond ① Polysaccharide backbone PeptidoglycanPeptidoglycan STRUCTURESTRUCTURE ：：
- 13. ② Tetrapeptide side chain ③ Peptide cross-bridges Bond to N – acetyl-muramic acid Bond to Tetrapeptide side chain and only found in GG++ bacteria
- 15. peptidoglycan forpeptidoglycan for GG++ bacteriabacteria
- 17. peptidoglycan forpeptidoglycan for GG-- bacteriabacteria
- 19. Function and medical significance of peptidoglycanFunction and medical significance of peptidoglycan ：： ①① Constructure of tenacious cell wall architectureConstructure of tenacious cell wall architecture Gram positive bacteria—Gram positive bacteria—threethree-dimensional structure-dimensional structure Gram negative bacteria—Gram negative bacteria— twotwo-dimensional structure-dimensional structure ②② Target of some antibioticsTarget of some antibiotics ：： For exampleFor example ：： Penicilin can inhibit the binding between tetrapeptide side chain and peptide cross-bridges, while lysozyme can hydrolyze the β-1,4 glucosidic bond
- 20. Penicilin Lysozyme Reactive site of some antibiotics in peptidoglycan
- 21. Cell wallCell wall 1.1. Chemical composition ：： A.A. Common component—— peptidoglycan B. Special componentB. Special component Gram positive bacteria——teichoic acidGram positive bacteria——teichoic acid Special surface proteinsSpecial surface proteins
- 22. Teichoic acidTeichoic acid Structure: Chemical composition phosphodiester bond Ribitol residue Glycerine residue Ribitol type Polymerizer Glycerine type
- 23. Classfication According to bonding site on the bacteria, teichoic acid can be classified into two types Membrane teichoic acid, also called lipoteichoic acid (LTA) Wall teichoic acid
- 24. teichoic acidteichoic acid Membrane teichoic acid Wall teichoic acid Peptidoglycan Teichoic acid Cell wall Phospholipid Protein Cell membrane
- 25. Function and medical significance of teichoicFunction and medical significance of teichoic acidacid ：： ① Bearing a strong negative charge. ② Adhesive attraction, relating to pathogenicity ③ They are strongly antigenic, helpful to identify and type a bacterium
- 26. cell wall forcell wall for GG++ bacteriabacteria
- 27. Cell wallCell wall 1.1. Chemical composition ：： A.A. Common component—— peptidoglycan B. Special componentB. Special component Gram positive bacteria——teichoic acidGram positive bacteria——teichoic acid Special surface proteinsSpecial surface proteins Gram negative bacteria——outer membraneGram negative bacteria——outer membrane
- 28. Outer membraneOuter membrane Structure Lipopolysaccharide lipid bilayer Lipoprotein Outer membrane Cell membrane Periplasmic space
- 29. Lipid A Core polysaccharide Specific polysaccharide (O- polysaccharide) LPS endotoxin
- 30. ①① Adsorption and excretionAdsorption and excretion ②② Barrier function ③③ Pathogenicity ④④ AntigenicityAntigenicity ⑤⑤ Receptor: F pilusReceptor: F pilus, phage, bacteriocin Function and medical significance ofFunction and medical significance of outer membraneouter membrane ：：
- 31. Cell wall forCell wall for GG-- bacteriabacteria
- 32. Comparison of cell wall between Gram negativeComparison of cell wall between Gram negative and Gram positive bacteriaand Gram positive bacteria Characters G+ G- Strength Tenacious Curmbly Thickness Thick ， 20 ～ 80nm Thin ， 5 ～ 10nm Layers of peptidoglycan More ， about 50 layers Few ， 1 ～ 3 layers Content of peptidoglycan High ， 50 ～ 80% of cell wall dry weight Little ， 10 ～ 20% of cell wall dry weight Structure of peptidoglycan Three-dimensional Two-dimensional Content of carbohydrate About 45% 15-20% Teichoic acid + - Outer membrane - +
- 33. Structures and compositions of cell wall G + bacterium Peptidoglycan-rich cell wall G+ bacterium cell wall --Peptidoglycan -- Teichoic acid
- 34. Structures and compositions of cell wall G- bacterium cell wall --Peptidoglycan --Outer membrane Lipoprotein Lipid bilayer LPS Lipid-rich cell wall
- 35. • Countering the effects of high intracellular osmoticCountering the effects of high intracellular osmotic pressure and maintaining the cell’s characteristicpressure and maintaining the cell’s characteristic shapeshape • Barrier and protection • Participate in substance exchange of bacterial cellParticipate in substance exchange of bacterial cell Function and medical significance of cell wall • Determinate some important characters of bacteriaDeterminate some important characters of bacteria pathogenicitypathogenicity immunogenicityimmunogenicity antibiotics sensitivity chromaticity : Differentiate bacteria: G + / G
- 36. 2. Wall-less forms of BacteriaWall-less forms of Bacteria (bacteria L form) Causes ： lysozyme, penicilin, antibody, complements, macrophage, neutrophile granulocyte, bile, UV, etc. Definition ： bacteria that the cell wall was impaired but maintain the competence of growth and cell division L form of Gram positive bacteria —— protoplast L form of Gram negative bacteria —— spheroplast
- 37. Characteristics ： • Appearance ： polymorph • Chromaticity ： Gram negative • Characteristic of cultivate ： hyperosmotic pressure, low concentrated agar with serum, and it grows very slow
- 40. Causes ： •Lysozyme, penicillin, antibody, complements, macropages, neutropile granulocyte, bile, UV, etc.
- 41. Colony Fried egg type colony Granular type colony Filamentous type colony
- 42. Fried egg (L) type Granular (G) type Filamentous (F) type
- 43. • Reversion: L-form bacteria can revert to its normal bacteria when the cause was removed at the early time of formation, the determinant condition is whether there is peptidoglycan remaining in the cell wall. And if it is subcultivated for many times in vitro, it can never be reverted. •Pathogenicity ： L-form bacteria bearing virulence （ diagnosis ） • Antibiotic sensitivity ： changed （ cure ）
- 44. Basic structure Cell wall Cell membrane Cytoplasm Nuclear material Special structure Capsule Spore Flagella Pili Structure of bacteriaStructure of bacteria
- 45. No cholesterol Important sturctures ： Cell membraneCell membrane MesosomesMesosomes Mesosomes are specialized structures formed by retractable, folded and curled cytoplasmic membrane, and divided into septal and lateral mesosome. also called chondroid.
- 47. Function •Material transportation •Respiration • Biosynthesis ： Penicillin-binding protein • Participate in cell division ： mesosome
- 48. Basic structures Cell wall Cell membrane Cytoplasm Nuclear material Special structures Capsule Spore Flagella Pili Structure of bacteria
- 49. Ribosomes: numerous, 15 - 20nm in diameter with 70S; distributed throughout the cytoplasm; site of protein synthesis ;sensitive to streptomycin and erythromycin CytoplasmCytoplasm Composed largely of water, together with proteins, nucleic acid, lipids and small amount of sugars and salts
- 50. Plasmids: extrachromosomal genetic elements Plasmids are small, circular ， extra- chromosomal ， double-stranded DNA molecules. They are capable of self-replication and contain genes that confer some important properties, such as antibiotic resistance ， virulence factors. Plasmids are not essential for cellular survival.
- 51. Inclusions: sources of stored energy, e,g volutin Inclusions are aggregates of various compounds that are normally involved in storing energy reserves or building blocks for the cell. Inclusions accumilate when a cell is grown in the presence of excess nutrients and they are often observed under laboratory conditions.
- 52. Basic structures Cell wall Cell membrane Cytoplasm Nuclear material Special structures Capsule Spore Flagella Pili Structure of bacteria
- 53. Lacking nuclear membrane, absence of nucleoli, hence known as nucleic material or nucleoid, one to several per bacterium. Nuclear material
- 54. Special structure of bacteria
- 55. Basic structures Cell wall Cell membrane Cytoplasm Nuclear material Special structures Capsule Spore Flagella Pili Structure of bacteria
- 56. CapsulesCapsules These are structures surrounding the outside of the cell wall. They are not essential to cell viability and some strains within a species will produce a capsule, whilst others do not. Capsules are often produce in vivo or on a eutrophic medium and lost during in vitro culture.
- 57. • Antigenicity – Composition: polysaccharide • Pathogenicity – Protection from phagocyte – Resistance to drying – Adherence Function and medical significance Formation condition In vivo or eutrophic
- 58. Basic structures Cell wall Cell membrane Cytoplasm Nuclear material Special structures Capsule Spore Flagella Pili Structure of bacteria
- 59. FlagellaFlagella • Some bacterial species are mobile and possess locomotory organelles - flagella. Flagella consist of a number of proteins including flagellin •The diameter of a flagellum is thin, 20 nm, and long with some having a length 10 times the diameter of cell. Due to their small diameter, flagella cannot be seen in the light microscope unless a special stain is applied. Bacteria can have one or more flagella arranged in clumps or spread all over the cell.
- 61. Classification According to the number and distribution of Flagella,Flagella, Flagella bacteria canFlagella bacteria can be classified into four types: Monotrichate Lophotrichate Amphitrichate Peritrichate
- 63. Basic structures Cell wall Cell membrane Cytoplasm Nuclear material Special structures Capsule Spore Flagella Pilus Structure of bacteria
- 64. Pili are hair-like projections of the cell , They are known to be receptors for certain bacterial viruses. Chemical nature is pilin Pilus
- 65. Classification: Ordinary pili or fimbriae: fine, rigid numerous, related to bacterial adhesion Sex pili: longer and coarser, only 1-4, related to bacterial conjugation
- 66. Function:
- 67. Basic structures Cell wall Cell membrane Cytoplasm Nuclear material Special structures Capsule Spore Flagella Pili Structure of bacteria
- 70. Formation and germination In vitro or malnutrition In vivo or eutrophic Bacteria (vegetative form) spore （ only one ） Bacteria (vegetative form, also only one) Form conditions (Dormant cell)(Dormant cell)
- 71. Multiple layers of resistant coats Dipicolinic acid or calcium dipicolinate Low content of water • Contains a complete nucleus material, ribosomes and energy-generating components • Highly resistant to heat, dessication, and chemicals Reasons High-pressure steam sterilization is the most effective way to kill the spores Characteristics:
- 72. Coats of sporeCoats of spore Spore coat Exosporium Spore wallCore Cortex Endomembrane Exomembrane
- 73. Medical significance • Identification of a bacteria: size, appearance and site • Standard of sterilization •Important source of infection —— anthrax, tetanus, etc.
- 74. Bacterial Metabolism and MultiplicationBacterial Metabolism and Multiplication
- 75. Bacterial MetabolismBacterial Metabolism Energy MetabolismEnergy Metabolism Important Metabolic ProductsImportant Metabolic Products 1. Catabolic processes1. Catabolic processes 2. Anabolic processes2. Anabolic processes
- 76. Products of anabolic processes and itsProducts of anabolic processes and its medical significancemedical significance Pyrogen ： a fever-producing substance mainly synthesized by gram negative bacteria, it is highly resistant to heat and it has the property of pyrogenicity. It is a very important microbial contamination evaluation index of biological products. Toxins and Invasive Enzymes ： Toxins: endotoxin, exotoxin Invasive Enzymes: hyaluronidase, streptokinase, streptodornase, and so on.
- 77. Pigments Classification—lipo solubility, water solubility Observation the pigments is helpful to the identification of a bacteria. Antibiotics Substance produced by some microbes and bearing the property of inhibition or killing effect to some other microbe or tumor cells.
- 78. Bactericin Substances produced by some strains of bacteria and bearing the antibacterial activity to the bacteria that related to bactericin-produce one. Vitamins
- 81. 1.NutritionNutrition Factors affecting bacterial growth and division Nutritive material:: Water Carbon source Nitrogen source Minerals Growth factors etc.etc. Requirments for Bacteria GrowthRequirments for Bacteria Growth
- 82. 2. Temperature2. Temperature The temperature suitable for most bacteria growth is from 20 to 40 centigrade, but the most appropriate temperature for cultivation of pathogenic bacteria is 37 centigrade. • Psychrophilic forms （ 15-20℃ ） • Mesophilic forms （ 30-37℃ ）： Include all human pathogens and opportunists. • Thermophilic forms （ 50-60℃ ）
- 83. 3. hydrogen ion concentrationhydrogen ion concentration ( pH ) The pH value that fit for most bacteria growth is The pH value that fit for most bacteria growth is from 7.2 to 7.6, but some bacteria grow well in from 7.2 to 7.6, but some bacteria grow well in acidity environment, while some bacteria just at the opposite.environment, while some bacteria just at the opposite. According to the appropriate pH value, bacteria can be classified into three groups just as follows: • Neutrophiles （ 5 to 8 ） • Acidophiles （ below 5.5 ） • Alkaliphiles （ above 8.5 ）
- 88. Generation time ： The time takes for a population of bacteria to double in number • many common bacteria ： 20 ～ 60 min •most common pathogens in the body ： 5 ～ 10 hours •Mycobacterium tuberculosis in medium: 18 ～ 20 hours