PPT 1

Question 1

Medical Microbiology

Answer 1

study of microbes important mediators of human disease (pathogenicity, epidemiology, diagnosis of infectious disease processes)

Question 2

Antonie van Leeuwenhoek

Answer 2

first observation of animalcules in 1674

• observed bacteria, spermatozoa, intracellular vacuoles and banding patterns on muscle cells
• published until 90

Question 3

Ferdinand Cohn

Answer 3

• founder of bacteriology
• found different bacterial shapes (coccus, bacillus, spriochete, filamentous)
• bacteria can sporulate

Question 4

Spontaneous Generation

Answer 4

• life in mud and soil

- curved neck flask

Question 5

Diseases of Wine and Beer

Answer 5

Louis Pasteur
1866 (wine) 1873 (beer)
-wine spoilage caused by biological action
-prevent spoilage (50 to 60) for 1-2 hours
-beer spoilage biologically caused
-pure yeast culture technique to prevent

Question 6

Discovery of Vaccination

Answer 6

18th century by Edward Jenner
-milkmaids rarely got smallpox, got similar eg. cowpox
-inoculating people w/ stuff from cowpox lesions, can protect people from small pox
vaccination (from cow)

Question 7

Pasteur and Vaccination

Answer 7

Pasteur pioneered use of weakened version of infectious agents (vaccines for chicken cholera, anthrax, rabies)

Question 8

Ignaz Semmelweiss

Answer 8

hungarian doctor working in Vienna

• women in hospitals gets fevers (~12%)
• transfer of substance from cadavers to patients
• handwashing lowered

Question 9

Germ Theory of Disease

Answer 9

-replaces humors

Question 10

Joseph Lister

Answer 10

• antiseptic surgery (after Semmelweis and Pasteur)
• depend on carbolic acid (phenol)
• 1865-8 dabbing PHENOL or wounds reduced
• FATHER OF MODERN SURGERY

Question 11

Infectious Disease

Answer 11

caused by pathogenic organisms (viruses, bacteria, fungi, parasites) directly/indirectly
-zoonotic diseases (infectious diseases spread to humans from animals

Question 12

Steps in Infectious Disease

Answer 12

1. Encounter host
2. Enter
3. Spread
4. Multiply
5. Damage
6. Outcome

Question 13

Encounter

Answer 13

Endogenous 
-component of normal microbiota
-microbe present in/on host
Exogenous 
-microbes not part of normal  microbiota

Question 14

Entry

Answer 14

Ingress
-entry w/o crossing epithelial barrier
(mucosal surfaces)
Penetration
-crossing epithelial barrier
disseminating pathogens (salmonella Typhi, Yersinia pestis, Micobacteria Tuberculosis)
-insect bites, cuts/scrapes, failure of innate immunity

Question 15

Spread

Answer 15

Lateral Propagation
from site of infection to adjacent contiguous tissues
Dissemination
from site of infection to distal tissues

Question 16

Multiplication

Answer 16

Incubation period: between infection and onset of symptoms

Question 17

Pathogen

Answer 17

microbial agent that can cause disease in a susceptible host

• bacteria
• viruses
• fungi
• protozoa
• prions
• viroids

Question 18

Koch’s Postulates

Answer 18

Robert Koch

1. Found in all diseased but not healthy
2. Microbe isolated and grown in pure culture
3. Cultured microbe causes disease in healthy
4. Reisolated from diseased and shown to be identical to normal

Question 19

Stanley Falkow’s Postulates

Answer 19

1. phenotype should be present in pathogenic strains only
2. inactivation of gene should reduce virulence
3. reversion of mutate gene to original allele should restore pathogenicity

Question 20

Human Micobiome

Answer 20

colonized by many microbes

• mouth
• throat
• nose
• skin
• stomach
• intestines
• vagina

Question 21

Germ-free animals

Answer 21

immuno compromised (low antibodies, low lymphocytes)

Question 22

vaginal microbiome dominated by

Answer 22

lactic acid bacteria

Question 23

Mouth Disease

Answer 23

periodontal disease, dental caries

Question 24

Carrier

Answer 24

pathogen present in/on host without dease

Question 25

Colonization

Answer 25

microbe replicates in/on host with or without disease

Question 26

Commensal

Answer 26

microbe present but doesn't harm host

Question 27

Mutualist

Answer 27

hot and microbe benefit from interaction

Question 28

Opportunistic pathogen

Answer 28

microbe usually doesn't cause disease unless host is compromised

Question 29

Teichoic Acids

Answer 29

Gram + polymer of glycerol or ribitol phosphate provide rigidity (attract cations) highly functionalized w/o components (eg. peptidoglycan)

Question 30

Lipopolysaccharide

Answer 30

``` outer leaflet of gram -ve (outer mem) Lipid A (acetyl, sugar moiety) N/O linked CORE (KDO/heptose) O-ANTIGEN (hydrophilic moiety) (endotoxin) (agonist) ```

Question 31

Myobacteria

Answer 31

``` Acid-Fast Bacteria -additional cell wall components -arabinogalactan and mycolic acid (long hydrophobic chains, impermeable) IMPERMEABLE TO HYDROPHILLIC DRUGS Gram + cause of TB ```

Question 32

Fungal Cell Wall

Answer 32

mannoproteins alpha beta glucan chains chitin mannoproteins stimulates host receptors

Question 33

Microbes 4 Steps to Infecting a Host

Answer 33

1. colonize surface 2. find compatible niche 3. get past innate and adaptive immune response 4. transmit to a new host

Question 34

Successful colonizers manage to avoid...

Answer 34

``` host defense pep neutrophil extracellular traps complement ciruculating antibiotics prevent phagocytosis prevent killing once phagocytosed ```