2. Bacteria?!! Sir azrimi

3. Bacterial Groups u Most widely accepted taxonomic classification for bacteria is Bergey’s Manual of Systematic Bacteriology. u 5000 bacterial species identified, 3100 classified. u Bacteria are divided into four divisions (phyla) according to the characteristics of their cell walls. u Each division is divided into sections according to: Gram stain reaction Cell shape Cell arrangements Oxygen requirements Motility Nutritional and metabolic properties u Each section contains several genera.

6. Bacteria grow tremendously fast when supplied with an abundance of nutrients. Different types of bacteria will produce different-looking colonies, some colonies may be colored, some colonies are circular in shape, and others are irregular. The characteristics of a colony (shape, size, pigmentation, etc.) are termed the colony morphology. Colony morphology is a way scientists can identify bacteria.

9. Streptococcus pyogenes Bacteria: Each distinct circular colony should represent an individual bacterial cell or group that has divided repeatedly. Being kept in one place, the resulting cells have accumulated to form a visible patch. Most bacterial colonies appear white, cream, or yellow in color, and fairly circular in shape. For example: BACTERIA Each distinct circular colony should represent an individual bacterial cell or group that has divided repeatedly. Being kept in one place, the resulting cells have accumulated to form a visible patch. Most bacterial colonies appear white, cream, or yellow in color, and fairly circular in shape

10. Bacillus subtilisProteus vulgaris

11. Yeasts: Yeast colonies generally look similar to bacterial colonies. Some species, such as Candida, can grow as white patches with a glossy surface Candida Albicans) is a type of yeast that can grow on the surface of skin(7)

12. Molds are actually fungi, and they often appear whitish grey, with fuzzy edges. They usually turn into a different color, from the center outwards. Two examples of molds are shown below: Green Mold (Trichoderma harzianum) Black Mold (Aspergillus nidulaus)

14.  Average bacteria 0.5 - 2.0 um in diam. RBC is 7.5 um in diam.  Surface Area ~12 um^2  Volume is ~4 um  Surface Area to Volume is 3:1  Typical Eukaryote Cell SA/Vol is 0.3:1  Food enters through SA, quickly reaches all parts of bacteria  Eukaroytes need structures & organelles Chapter 4

15.  Coccus Chain = Cluster =  Bacillus Chain =  Coccobacillus  Vibrio = curved ?? ?? ?? ?? Chapter 4

17.  Flagella  Pili  Capsule  Plasma Membrane  Cytoplasm  Cell Wall  Lipopolysaccharide s  Teichoic Acids  Inclusions  Spores Chapter 4

19.  Motility - movement  Swarming occurs with some bacteria Spread across Petri Dish Proteus species most evident  Arrangement basis for classification Monotrichous; 1 flagella Lophotrichous; tuft at one end Amphitrichous; both ends Peritrichous; all around bacteria  Observe Picture in Micro Lab. Chapter 4

21. Mono- or Lophotrichorus

22. Chapter 4

23.  Short protein appendages smaller than flagella  Adhere bacteria to surfaces E. coli has numerous types  K88, K99, F41, etc. Antibodies to will block adherance  F-pilus; used in conjugation Exchange of genetic information  Flotation; increase boyancy Pellicle (scum on water) More oxygen on surface Chapter 4

25.  Glycocalyx - Polysaccharide on external surface  Adhere bacteria to surface S. mutans and enamel of teeth  Prevents Phagocytosis Complement can’t penetrate sugars Chapter 4

26.  80% Water {20% Salts-Proteins) Osmotic Shock important  DNA is circular, Haploid Advantages of 1N DNA over 2N DNA More efficient; grows quicker Mutations allow adaptation to environment quicker  Plasmids; extra circular DNA Antibiotic Resistance  No organelles (Mitochondria, Golgi, etc.) Chapter 4

27.  Bilayer Phospholipid  Water can penetrate  Flexible  Not strong, ruptures easily Osmotic Pressure created by cytoplasm Chapter 4

31. Cell Wall  Peptido-glycan Polymer (amino acids + sugars)  Unique to bacteria  Sugars; NAG & NAM N-acetylglucosamine N-acetymuramic acid  D form of Amino acids used not L form Hard to break down D form  Amino acids cross link NAG & NAM

32. Chapter 4

38.  Determine shape of bacteria  Strength prevents osmotic rupture  20-40% of bacteria  Unique to bacteria  Some antibiotics effect directly Penicillin Chapter 4

39. Video Clip on Cell Wall

40.  Gram + only  Glycerol, Phosphates, & Ribitol  Attachment for Phages Chapter 4

42. Lipopolysaccharide (LPS)  Endotoxin or Pyrogen Fever causing Toxin nomenclature  Endo- part of bacteria  Exo- excreted into environment  Structure Lipid A Polysaccharide  O Antigen of E. coli, Salmonella  G- bacteria only Alcohol/Acetone removes

43. Chapter 4

45.  Functions Toxic; kills mice, pigs, humans  G- septicemia; death due to LPS Pyrogen; causes fever  DPT vaccination always causes fevers Adjuvant; stimulates immunity  Heat Resistant; hard to remove  Detection (all topical & IV products) Rabbits (measure fever) Horse shoe crab (Amoebocytes Lyse in presence of LPS) Chapter 4

46.  Appearance of Colonies Mucoid = Smooth (lots of LPS or capsule) Dry = Rough (little LPS or capsule)  O Antigen of Salmonella and E. coli 2,000 different O Ags of Salmonella 100’s different O Ags of E. coli  E. coli O157  O Ags differ in Sugars, not Lipid A Chapter 4

47.  Resistant structure Heat, irradiation, cold Boiling >1 hr still viable  Takes time and energy to make spores  Location important in classification Central, Subterminal, Terminal  Bacillus stearothermophilus -spores Used for quality control of heat sterilization equipment  Bacillus anthracis - spores Used in biological warfare Chapter 4

50.  G+ Thicker cell wall Teichoic Acids  G- Endotoxin - LPS  Which are more sensitive to Penicllin?  Alcohol/Acetone affects which more? Chapter 4

51.  Cell Wall  Teichoic Acids  LPS  Endospores  Circular DNA  Plasmids Chapter 4