microbiology
DESCRIPTION
MICROBIOLOGY. STUDY OF BACTERIA & VIRUSES. 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?. Water Food/nutrients Oxygen - PowerPoint PPT PresentationTRANSCRIPT
MICROBIOLOGYSTUDY OF BACTERIA & VIRUSES
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? Water Food/nutrients Oxygen
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 Cells Cross 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
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,
diplobacilli Strepto
Arranged chains Streptobacilli
Staphlo Arranged in
clusters staphlococcus
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 anthrax Koch’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