BACTERIA AND VIRUSES 1 Bacteria are very small

BACTERIA AND VIRUSES 1

Bacteria are very small 2

This is a pore in human skin and the yellow spheres are bacteria 3

Bacteria are very small compared to cells with nuclei 4

Bacteria compared to a white blood cell that is going to eat it 5

Clean skin has about 20 million bacteria per square inch 6

Evolution/Classification Most numerous on Earth ¡ Most Ancient ¡ Microscopic Prokaryotes ¡ Evolution has yielded many species adapted to survive where no other organisms can. ¡ Grouped based on: ¡ l l l Structure, physiology, molec. Composition reaction to specific types of stain. Eubacteria= Germs/bacteria Archaebacteria 7

Kingdom Archaebacteria First discovered in extreme environments ¡ Methanogens: Harvest energy by converting H 2 and CO 2 into methane gas ¡ l Anaerobic, live in intestinal tracts Extreme halophiles: Salt loving, live in Great Salt Lake, and Dead sea. ¡ Thermoacidophiles: Live in acid environments and high temps. ¡ l Hot Springs, volcanic vents 8

Volcanic vents on the sea floor 9

Chemosynthetic bacteria use the sulfur in the “smoke” for energy to make ATP. 10

The red color of this snow is due to a blue-green bacteria 11

Kingdom Eubacteria ¡ Can have one of three basic shapes 1. Bacilli – rod-shaped 2. Spirilla – spiral-shaped 3. Cocci – sphere-shaped Staphylococci – grape-like clusters Streptococci – in chains SHOW ME 12

BACTERIA PICS 13

Bacillus bacteria are rod or sausage shaped 14

Coccus bacteria are sphere or ball shaped 15

Spirillium bacteria have a corkscrew shape 16

Diplo-bacteria occur in pairs, such as the diplococcus bacteria that causes gonorrhea 17

Staphylo bacteria occur in clumps, such as this staphylococcus bacteria that causes common infections of cuts 18

Streptobacteria occur in chains of bacteria, such as this streptococcus bacteria that causes some types of sore throats 19

Spirillium bacteria 20

Diplobacillus bacteria 21

Streptococcus bacteria 22

Staphylococcus bacteria 23

The tip of a needle The red and yellow dots are bacteria 24

Gram Stain ¡ Gram-positive retain stain and appear purple l ¡ Have thicker layer in cell wall. Gram-negative do not retain stain and take second pink stain instead. Phylum Shape Motility Metabolism Gram reacion Cyanobacteria Bacilli, Cocci Gliding, some nonmotile Aerobic, Gramphotosynthetic negative autotrophic Spirochetes Spirals Corkscrew Aerobic, and anaerobic; heterotrophic Gram-Pos Bacilli, cocci Flagella; some nonmotile Aer/anaer. ; Mostly gramheterotrophic, positive photosynthetic Proteobacteria Bacilli, cocci, spiral Flagella; some nonmotile Aer/anaer. ; heterotrophic, photosynthetic autotrophic Gramnegative 25

STRUCTURE OF BACTERIA Structure Function Cell Wall Protects and gives shape Outer Membrane Protects against antibodies (Gram Neg. Only) Cell Membrane Regulates movement of materials, contains enzymes important to cellular respiration Cytoplasm Contains DNA, ribosomes, essential compounds Chromosome Carries genetic information Plasmid Contains some genes obtained through recomb. Capsule & Protects the cell and assist in attaching cell to Slime Layer other surfaces Endospore Protects cell against harsh environments Pilus Assists the cell in attaching to other surfaces Flagellum Moves the cell 26

No Nucleus-DNA in Cytoplasm 27

Nutrition and Growth ¡ ¡ Heterotrophic or Autotrophic Some are Photoautotrophs – Use sunlight for Energy Some are Chemoautotrophs. Many are Obligate Anaerobes. l Oxygen = Death ¡ Ex. ¡ Some are Faculatative Anaerobes l With or without Oxygen ¡ Ex. ¡ ¡ Clostridium tetani – Tetanus Escherichia Coli Some are Obligate Aerobes l Ex. ) Mycobacterium tuberculosis Temperature requirements l Some are Thermophilic, Some prefer acidic envmt. 28

These heterotrophic bacteria digest oil -remember oil is partially decayed plant and animal cells 29

REPRODUCTION IN BACTERIA 30

No Nucleus-DNA in Cytoplasm 31

BACTERIA REPRODUCES BY FISSION First the chromosomal DNA makes a copy The DNA replicates 32

NEXT THE CYTOPLASM AND CELL DIVIDES The two resulting cells are exactly the same 33

In addition to the large chromosomal DNA, bacteria have many small loops of DNA called Plasmids 34

Genetic Recombination ¡ Nonreproductive Methods bacteria can acquire new genetic material. Characteristic Transformation Conjugation Transduction Method of DNA Across cell wall Transfer and cell membrane of recepient Through a By a virus conjugation bridge between two cells Plasmid transfer Yes Not likely Chromosome transfer No Sometimes No Antibiotic resistance acquired Yes Sometimes 35

TRANSFORMATION This plasmid of DNA is new to the bacteria – added by transformation! Produces the glowing protein 36

CONJUGATION 37

TRANSDUCTION 38

Bacteria and Disease Pathogen Areas affected Mode of transmission Botulism Clostridium botulinum Nerves Improperly preserved food Cholera Vibrio cholerae Intestine Contaminated water Dental Caries Streptococcus mutans, sanguis, salivarius Teeth Environment to mouth Gonorrhea Neisseria gonorrhoeae Urethra, fallopian Sexual contact Lyme disease Berrelia burgdorferi Skin, joints Tick bite Rocky Mountain SF Rickettsia recketsii Blood, skin Tick bite Salmonella Intestine Contaminated food, water Strep throat Streptococcus pyogenes URT, blood, Sneezes, coughs, etc. skin Tetanus Costridium tetani Nerves Contaminated wounds Tuberculosis Mycobacterium tuberculosis Lung, bones coughs 39

Some bacteria cause diseases -Disease causing bacteria are call PATHOGENIC 40

Helicobacter pylori is the pathogenic bacteria that can causes ulcers 41

Leprosy is a bacterial infection that decreases blood flow to the extremities resulting in the deterioration of toes, ears, the nose and the fingers. 42

BOTULISM 43

CHOLERA 44

DENTAL CARIES 45

ROCKY MOUNTAIN SF 46

LYME DISEASE 47

SALMONELLA 48

STREP THROAT 49

TETANUS 50

TUBERCULOSIS 51

Common Antibiotics Antibiotic Mechanism Target bacteria Penicillin Inhibits cell wall synthesis Gram Positive Ampicillin Inhibits cell wall synthesis Broad spectrum Bacitracin Inhibits cell wall synthesis Gram Positive – Skin Ointment Cephalosporin Inhibits cell wall synthesis Gram Positive Tetracycline Inhibits Protein Synthesis Broad spectrum Streptomycin Inhibits Protein Synthesis Gram Neg. tuberculosis Sulfa drug Inhibits cell metabolism Bacterial meningitis, UTI Rifampin Inhibits RNA synthesis Gram Pos. , some Neg. Quinolines Inhibits DNA Synthesis UTI 52

Some Final Information ¡ ¡ Because antibiotics have been overused, many diseases that were once easy to treat are becoming more difficult to treat. Some Bacteria are Useful l Ex. ) Producing and Processing food Breaking down dead organic material Make unripened cheese like ricotta and cottage by breaking down the protein in milk. 53

VIRUSES Non-living but depends on the living! 54

STRUCTURE ¡ ¡ ¡ Nonliving Composed of Nucleic acid and protein Cause many diseases Virology – Study of Viruses Comparison of Viruses and Cells below Char. Of Life Virus Cell Growth No Yes Homeostasis No Yes Metabolism No Yes Mutation Yes Nucleic acid DNA or RNA DNA Reproduction Only within host cell Independently by cell division Structure Nucleic acid core, protein covering, some have envelope Cytoplasm, cell membrane, etc. . 55

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Here is a non-enveloped bacteria virus inserting it’s DNA into a bacterial cell. 57

Some virus are pushed out by the cell, taking some of the cell membrane with them. 58

Characteristics of Viruses ¡ ¡ ¡ 2 essential features 1. Nucleic Acid l May be DNA or RNA l Helical, closed loop, or long strand 2. Protein Coat – called CAPSID Some have ENVELOPE l Ex. Influenza, chickepox, herpes simplex, HIV VIRAL SHAPE l Icosahedron – 20 triangular faces ¡ Ex. ) herpes, chickenpox, polio l Helix – Coiled spring ¡ EX. )Rabies, measles, tobacco mosaic 59

All viruses have two main parts: 1. DNA or RNA – genetic info 2. Capsid – a protein encasement 60

Grouping Viruses ¡ Grouped according to: l Presence of Capsid and envelope – shape l RNA or DNA, single or double stranded – struct. Viral Group Nucleic Acid Shape and Structure Example Papovaviruses DNA Icosahedral, non-env. Warts, cancer Adenoviruses DNA Icosahedral, non-env. Resp. & intestinal infections Herpesviruses DNA Icosahedral, enveloped Herpes simplex, chicken pox, mono, shingles Poxviruses DNA Complex brick, enveloped Small pox, cow pox Picornaviruses RNA Icosahedral, non-env. Polio, hepatitis, cancer Myxoviruses RNA Helical, enveloped Influenza A, B, C Rhabdoviruses RNA Helical, enveloped Rabies Retroviruses RNA Icosahedral, enveloped AIDS, cancer 61

Grouping Viruses ¡ Viroids- The smallest known particle that can replicate. l l ¡ Disrupt plant cell metabolism Can destroy entire crops Prions – Abnormal forms of proteins that clump together inside cells. l l Clumping eventually kills the cell Examples Scrapie – in sheep ¡ Mad Cow Disease ¡ 62

PRIONS – man-made problem? 63

Viral Replication ¡ ¡ ¡ Can replicate only by invading host cell and using its enzyme and organelles. Bacteriophage – viruses that infect bacteria l Used to study viruses Lytic Cycle l Viral genome is released into the host cell l Replication follows immediately l Cellular components used to make new viruses l Viral enzyme kills cell. 64

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Viral Replication Picture http: //www. mcgrawhill. ca/school. Graphics/biology 2_1. mpg Click Movie to Play 66

Replication cont’ ¡ Lysogenic Cycle l Nucleic acid of virus becomes part of the host cell’s chromosome l Nucleic acid remains in the cell in this form for many generations l HIV follows this pattern l HIV infects WBC and remains as proviruses l As immune system fails, opportunistic infections occur = AIDS 67

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Here is a classic picture of HIV viral progeny being released from the surface of a T- cell. Notice the membrane coating they receive. 69

Viruses and Human Disease ¡ Control and Prevention of spread. l Vaccination & Antiviral drugs ¡ ¡ Emerging Viruses – exist in isolated habitats l ¡ Ex. ) chickenpox vaccine, AZT, Acyclovir, protease inhibitors. Do not usually infect humans unless environmental conditions favor contact. Several viruses are now linked to cancers such as leukemia, liver cancer, Burkitt’s lymphoma, cervical cancer. 70

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PAPOVAVIRUSES BACK 75

ADENOVIRUSES BACK 76

HERPESVIRUSES BACK 77

POXVIRUSES BACK 78

PICORNAVIRUSES BACK 79

After polio infections, the killer T-cell have destroyed the motor neurons that are producing the virus. The result is a loss of muscle control including the diaphragm. The iron lung changes the pressure to pump air in and out of the lungs. 80

Which US President had polio? 81

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MYXOVIRUSES BACK 84

RHABDOVIRUSES BACK 85

RETROVIRUSES BACK 86

What does bacteria have to do with DNA technology? Bacteria are simple ¡ Bacteria have DNA that is made of nucleotides (A, T, G, C) ¡ Bacteria can be grown quickly and easily ¡ l Give them food, warmth and dark (like inside you shoe) and they will multiply like mad (binary fission) 87

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¡ Bacteria have plasmids – extra DNA in the form of a circle 89

¡ ¡ ¡ Plasmids are DNA – made out of A, T, C, G nucleotides The same nucleotides found in human DNA, plant DNA, dog DNA, fish DNA, fungus DNA Get it – it’s all the same molecule 90

Sticky ends? Restriction enzymes? r. DNA? ¡ So… why not take out a plasmid, cut it apart and add any other DNA piece that we want! 91

¡ Then put it back in the bacteria and grow more bacteria with that new plasmid that we have created! Hmmm? http: //www. learner. org/channel/courses/biology/archive/ani mations. html 92

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