STUDY OF BACTERIA & VIRUSES MICROBIOLOGY. WHAT ARE MICROBES? Microscopic organisms that include...
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Transcript of STUDY OF BACTERIA & VIRUSES MICROBIOLOGY. WHAT ARE MICROBES? Microscopic organisms that include...
STUDY OF BACTERIA & VIRUSES
MICROBIOLOGY
WHAT ARE MICROBES?
Microscopic organisms that include bacteria, fungi, algae, protozoa & viruses
Less than 5% are classified as pathogenic (disease causing)
WHAT DO M/O’S NEED?
WaterFood/nutrientsOxygen
Aerobes, anaerobes, facultative anaerobes
Temperature Psychrotrophic (32-45 F) Mesophilic (60-110 F) Thermophilic (110-150 F)
pH 7 optimal Reproduce 4.5 - 10
REPRODUCTION
Bacteria Binary Fission
1 bacteria clone itself Produce 2 identical
cells Conjugation
Two bacteria share genetic information
Produce 2 new cells Transformation
Bacteria takes genes from environment
REPRODUCTION
Molds Fragmentation
Pieces break off & create new individual
Budding Copy (similar b.
fission) New copy break off of
original Spores
Reproductive cells released either free-form or join w/ another
BACTERIA
Prokaryotic cells No nucleus Contain genetic
material plasmid Single round
chromosome Ribosomes –make
proteins Pilli
protein hair-like structures
Help cells attach Flagella
movement
BACTERIAL STRUCTURES
Cell Wall Rigid structure either carbs or
proteins Prevents osmotic pressure
(cytolysis)Capsule
Sticky gelatin surrounds c.wall Prevents wbc from attaching
Outer Membrane (some forms) Toxic lipid bilayer
Endospore (some forms) Hard outer covering Prevents drying out Allows go dormant
MOLD
Eukaryotic CellsCross between plant
& animal cell Cell walls No Chloroplasts Consumers
saprophyte (absorb nutrients from dead, decaying organisms)
MOLD
Multi-cellular organisms composed of branches called “hypae” Vegetative hypae
attached to host Aerial hypae absorb
O2 from air
M/O IN ENVIRONMENT LAB
What area of EPHS will support the most amount of microbial growth?
20 Possible locations:1. -2. -3. -4. -5. -6. -7. -8. -9. -
10. -11. -12. -13. -14. -15. -16. -17. -18. -19. -20. -21. - Control
THEORIES ON DISEASE
Prior to physical evidence of m/o’s Common beliefs witchcraft, sins against God Lucretius (Roman philosopher)
Published theories form of poem Renounced idea of gods/spirits
Fracastoro Theory of chemical “spores” travel great distances
Leeuwenhoek Credited w/ discovering bacteria Looking a plaque family member’s teeth
GERM THEORY OF DISEASE
Bassi Discovered silkworm
disease caused by a fungus
Killing caterpillars & destroyed silk industry
Berkeley Proved Great Potato
Blight caused by a fungus
GERM THEORY OF DISEASE
Lister Developed system
antiseptic surgery Combination heat &
phenol alcohol
Koch Developed criteria
proving relationship btw m/o’s & disease
Studied anthraxKoch’s postulates
M/o found all cases disease Maintained pure culture Produce original infection,
after generations in culture Isolated from inoculated
host & recultured
GERM THEORY OF DISEASE
Pasteur Developed 1st vaccine
for Rabies Used attenuated strain
(lost ability cause disease)
Gram Developed system of
staining procedures Divides bacteria 2 grps
Gram + turn violet Cell walls simple carbs Less pathogenic
Gram - turn red Cell walls protein &
extra lipid outer membrane
Resistant antibiotics Pathogens
BACTERIAL SHAPES
Cocci (coccus) Round cells
Bacilli (bacillus) Rod shaped
Spirella (spirellum) Thick, rigid spiral
Spirochete Thin, flexible spiral
Vibrio Curved, comma
shaped
BACTERIAL ARRANGEMENTS
Diplo Arranged in pairs Diplococci,
diplobacilliStrepto
Arranged chains Streptobacilli
Staphlo Arranged in clusters staphlococcus