Animal Health 3a
Terms
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- What are some functions of cell walls?
- Responsible for cell shape. Prevention of cell rupture.
- What are some characteristics of bacterial cells?
- Cell Wall, no nucleus, no discrete organelles, .2-2microm diameter & 2-8 microm length
- What are the 3 shapes of bacteria
- Coccus (spherical), Bacillus (rods), Spiral
- What are the 3 planes of growth called?
- Diplococci (doublets), Streptococci (lines), Staphylococci (groups)
- Describe the glycocalyx and list two of its functions
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1. "Sugar coat"
2. Capsule
3. Sticky, gelatinous polymer made up of polysaccharides and polypeptides
Functions: protection and adsorption - List several objects inside the cell wall
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1. Plasma (cytoplasmic) membrane for selective permeability
2. Cytoplasm (80% water)
3. Nuclear area (nucleoid) - What are ribosomes used for? Inclusion?
- protein synthesis. Inclusion=reserve nutrient deposits
- What are several ways to classify bacteria?
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1. Gram stain
2. Shape
3. Arrangement
4. Mobility method
5. Atmospheric requirements
6. Biochemical reactions
7. Growth requirements
8. G/C ratio of nuclear material - List several ways of entry
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1. normally present
2. Broken skin
3. Respiratory tract
4. Gastrointestinal tract
5. Urogenital tract
6. Conjunctiva/mucous membrane - What are some mechanisms of spread?
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1. Physical contact
2. Air
3. Food and water
4. Insects
5. Fomites (inanimate objects) - What are 3 mechanisms of anti bacterial resistance
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1. Species insusceptibility
2. Innate immune system
3. Acquired immune system - What are some methods of bacterial disease production?
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1. Release of toxins
2. Release of destructive enzymes
3. Intracellular destruction - What is the difference b/w endo and exotoxins? Give examples of each
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Exotoxin: produced in cell and secreted by the cell or released when host cell is destroyed (tetanus, botulism)
Endotoxin: Walls of Gram (-) bacteria only. Toxins are released only if the bacterial cell dies (salmonella) - Give 5 examples of destructive enzymes. What are they able to do.
- Hyaluronidase, collagenas, elastase, protease, fibrinoytics. They can break down tissues and destroy antibodies.
- What is intracellular destruction?
- Due to expanding physical bulk (bacterial growth w/in the cell). Such bacteria are resistant to lysozymes (TB, brucellosis, listeriosis)
- What are two tests done to test which antibiotic to use?
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1. MIC (minimum inhibitory concentration): the lowest level of antibiotic that will kill bacteria
2. Kirby Bauer: multiple antibiotic sensitivity discs - What are some things to consider before prescribing the antibiotic?
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1. Will drug distribute to the site of infection?
2 Will drug reach MIC levels in the patient?
3. Resistance status of the host
4. Toxicity
5. Compliance
6. Economics