Microbiology test 3-1

Skin

Because of Relatively low PH of skin (5.6) not many MO's can grow on skin. STAPHOLOCOCCUS EPERDEMIDIS on skin of all healthy people

• Eyes
• Relatively MO free because of naturally occuring enzyme Lysozyme
• Respritory tracht

Majority of MO's are found in UPPER respritory tracht. Lower tracht should be MO free (lungs)

• Digestive tracht
• a) Mouth--because of Lysoyme most MO destroyed
• b) Stomach--because of low PH of stomach (2.0) could have Heliobacter Pylori.
• Contents of stomach has 10² germs per gram of content (low) germs are protected by content.

• C) Small intestine--Ph will rise (7.0) creates ideal condidtion for MO that escapes stomach to multiply and grow. Content of Small intestines is 10⁶ germ/gram of content.
• Type of Germs in Small intesties
• E-COLI-- ENTEROBACTER--ENTEROCOCCI
• d) Large intestine- excellent invironment for growth of MO. Both Aerobic and Non-Aerobic. (CLAUSTRIDIUM--ANEROBIC) Candida Albicans (yeast) # of MO 10⁹ germs/gram of content

Genital organs

• Vagina--from puberty-menopause PH of vagina is acidic (6-6.5) (acidophile heaven) i.e. LACTO BACILLUS - CANDIDA ALBICANS
• Toxic shock syndrome caused by STAPYLOCOCCUS AUREUS. during menapause vagina becomes more nuetral (7-7.5) more conducive to MO to grow.

Penis -- because of anatomy not many MO's on penis. Pee it out.

Blood -- Sterile

Milk -- Sterile

Diseases such as CHOLERA AND TYPOID FEVER originated in India and Pakistan and transported to Europe and US.

Sexually trasmitted siseas -Syphillis and Gonerhea transmitted by white men to NA Indians and eskimo's.

Ebola Virus -cousin of HIV Kills in 3 weeks. River in West Africa. Massive Vomit of blood first symptom.

• 2 major methods of transmission

1. Direct Method. Germs passed from person to person directly. i.e. all types of sexual activity and intimate kissing

2. In-Direct Method. Passed from Person to Person by insects, i.e. mosquitos,food poisionin, use of dirty utensils. Bed spreads at motel.

What makes a MO Pathogenic ??

• 1. Pili
• 2. Capsule
• 3. enzymes
• a)Hemolysin (breakdown RBC) --Staph Aureus
• b)Leukocidin (breakdown WBC)
• c)Coagulase (coagulates blood plasma) --Staph Aureus
• d) Collagenanse - Break down Collagen)

4. Production of toxins

• a)Exotoxins--produced by gram positive only
• Neurotoxins--act on Central Nervous system --Claustridium Botulinum
• Eneterotoxins --damage GI system --Staph Aureus

b) Endotoxins --Gram Negative only (LPS)

What happens when Pathogen gets in our body?

• 1. Incubation Period --The time from ingestion of the germ to apperance of first symptom (varies among MO) i.e. Staph Aureus food poisining within 3 hours.
• 18-24 hours for SAMONELLA. 3-6 months for T.B.

2. Prodromal Period -- whe the first symptoms appear "I think I'm coming down with something"

3. Invasive Period --When Pathogen has started attacking the tissues of the host. Practically ALL symptoms appear during this period. Fever Starts.

Pathogens produce PYROGENS which act on the hypothalamus gland that raises body temp.

4. Acme Phase --During this phase the battle between Pathogen and Immune cells reaches its height.

5. Decline Phase --Pathogen has been destroyed

6. Recover Phase --has to rest to build up immune system.

Communicable Diseases --Spread among individuals

Non-communicable diseases --Not spread among people

Indemic Diseases -- Occur at LOW levels-small area

Epedemic --Large numbers -- large area

Pandemic --World wide Disease

Acute--Develops rapidly-short duration

Chronic - Develops slowly --Lasts long time (i.e. TB)

Systemic --Spread throughout the body

Local-- Affects only certain part of body -does not spread

Bacteremia (septicemia) apperance of Bacteria in Blood

Viremia --Virus in Blood

Toxemia --Apperance of Toxins in Blood

Fungemia -- Fungus and Mold in Blood