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