Download presentation
Presentation is loading. Please wait.
1
Bacteria
4
Bacteria are very small
5
This is a pore in human skin and the yellow spheres are bacteria
Scanning electron image of bacteria on skin.
6
Bacteria compared to a white blood cell that is going to eat it
7
Clean skin has about 20 million bacteria per square inch
8
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: Structure, physiology, molec. Composition reaction to specific types of stain. Eubacteria= Germs/bacteria Archaebacteria
9
Kingdom Archaebacteria
First discovered in extreme environments Methanogens: Harvest energy by converting H2 and CO2 into methane gas 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. Hot Springs, volcanic vents
10
The red color of this snow is due to a blue-green bacteria
11
Kingdom Eubacteria Bacilli – rod-shaped Spirilla – spiral-shaped
Can have one of three basic shapes Bacilli – rod-shaped Spirilla – spiral-shaped Cocci – sphere-shaped Staphylococci – grape-like clusters Streptococci – in chains
12
BACTERIA PICS
13
Coccus bacteria are sphere or ball shaped
14
Spirillium bacteria have a corkscrew shape
15
Staphylo - bacteria occur in clumps, such as this staphylococcus bacteria that causes common infections of cuts
16
Strepto- bacteria occur in chains of bacteria, such as this streptococcus bacteria that causes some types of sore throats
17
Spirillium bacteria
18
The red and yellow dots are bacteria
The tip of a needle The red and yellow dots are bacteria
19
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 Chromo-some Carries genetic information Plasmid Contains some genes obtained through recomb. Capsule & Slime Layer Protects the cell and assist in attaching cell to other surfaces Endospore Protects cell agains harsh enviornments Pilus Assists the cell in attaching to other surfaces Flagellum Moves the cell
20
No Nucleus-DNA in Cytoplasm
21
Nutrition and Growth Temperature requirements
Heterotrophic or Autotrophic Some are Photoautotrophs – Use sunlight for Energy Some are Chemoautotrophs. Many are Obligate Anaerobes. Oxygen = Death Ex. Clostridium tetani – Tetanus Some are Faculatative Anaerobes With or without Oxygen Ex. Escherichia Coli Some are Obligate Aerobes Ex.) Mycobacterium tuberculosis Temperature requirements Some are Thermophilic, Some prefer acidic envmt.
22
Bacteria and Disease 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 Salmonella Contaminated food, water Strep throat Streptococcus pyogenes URT, blood, skin Sneezes, coughs, etc. Tetanus Costridium tetani Contaminated wounds Tuberculosis Mycobacterium tuberculosis Lung, bones coughs
23
Helicobacter pylori is the pathogenic bacteria that can causes ulcers
24
Leprosy is a bacterial infection that decreases blood flow to the extremities resulting in the deterioration of toes, ears, the nose and the fingers.
25
BOTULISM
26
CHOLERA
27
DENTAL CARIES
28
ROCKY MOUNTAIN SF
29
LYME DISEASE
30
SALMONELLA
31
STREP THROAT
32
TUBERCULOSIS
33
Common Antibiotics Antibiotic Mechanism Target bacteria Penicillin
Inhibits cell wall synthesis Gram Positive Ampicillin Broad spectrum Bacitracin Gram Positive – Skin Ointment Cephalosporin Tetracycline Inhibits Protein Synthesis Streptomycin Gram Neg. tuberculosis Sulfa drug Inhibits cell metabolism Bacterial meningitis, UTI Rifampin Inhibits RNA synthesis Gram Pos., some Neg. Quinolines Inhibits DNA Synthesis UTI
34
How Science is Helping Bacteria
Because antibiotics have been overused, many diseases that were once easy to treat are becoming more difficult to treat. Some Bacteria are Useful Ex.) Producing and Processing food Breaking down dead organic material Make unripened cheese like ricotta and cottage by breaking down the protein in milk.
35
Non-living but depends on the living!
VIRUSES Non-living but depends on the living!
36
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 Metabolism Mutation 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..
37
Here is a non-enveloped bacteria virus inserting it’s DNA into a bacterial cell.
38
Some virus are pushed out by the cell, taking some of the cell membrane with them.
39
Characteristics of Viruses
2 essential features 1. Nucleic Acid May be DNA or RNA Helical, closed loop, or long strand 2. Protein Coat – called CAPSID Some have ENVELOPE Ex. Influenza, chickepox, herpes simplex, HIV VIRAL SHAPE Icosahedron – 20 triangular faces Ex.) herpes, chickenpox, polio Helix – Coiled spring EX.)Rabies, measles, tobacco mosaic
40
All viruses have two main parts:
DNA or RNA – genetic info Capsid – a protein encasement
41
Grouping Viruses Grouped according to:
Presence of Capsid and envelope – shape RNA or DNA, single or double stranded – struct. Viral Group Nucleic Acid Shape and Structure Example Papovaviruses DNA Icosahedral, non-env. Warts, cancer Adenoviruses Resp. & intestinal infections Herpesviruses Icosahedral, enveloped Herpes simplex, chicken pox, mono, shingles Poxviruses Complex brick, enveloped Small pox, cow pox Picornaviruses RNA Polio, hepatitis, cancer Myxoviruses Helical, enveloped Influenza A, B, C Rhabdoviruses Rabies Retroviruses AIDS, cancer
42
Grouping Viruses Viroids- The smallest known particle that can replicate. Disrupt plant cell metabolism Can destroy entire crops Prions – Abnormal forms of proteins that clump together inside cells. Clumping eventually kills the cell Examples Scrapie – in sheep Mad Cow Disease
43
PRIONS – man-made problem?
44
Viral Replication Can replicate only by invading host cell and using its enzyme and organelles. Bacteriophage – viruses that infect bacteria Used to study viruses Lytic Cycle Viral genome is released into the host cell Replication follows immediately Cellular components used to make new viruses Viral enzyme kills cell.
46
Replication cont’ Lysogenic Cycle
Nucleic acid of virus becomes part of the host cell’s chromosome Nucleic acid remains in the cell in this form for many generations HIV follows this pattern HIV infects WBC and remains as proviruses As immune system fails, opportunistic infections occur = AIDS
48
Here is a classic picture of HIV viral progeny being released from the surface of a T- cell. Notice the membrane coating they receive.
49
Viruses and Human Disease
Control and Prevention of spread. Vaccination & Antiviral drugs Ex.) chickenpox vaccine, AZT, Acyclovir, protease inhibitors. Emerging Viruses – exist in isolated habitats 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.
50
PAPOVAVIRUSES BACK
51
POXVIRUSES BACK
52
PICORNAVIRUSES Polio BACK
53
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.
55
MYXOVIRUSES BACK
56
RHABDOVIRUSES BACK
57
RETROVIRUSES AIDS BACK
58
Time to take ownership What you need to know!
Bacteria and virus structures Types of bacteria Types of viruses How bacteria and viruses cause infection What can be done to treat, cure or prevent viral and bacterial infections.
Similar presentations
