LAB EXAM #1

Question 1

Paul Ehrlich:

Answer 1

Discovered chemotherapy and magic bullets- salvarsan to treat syphilis

Question 2

Alexander Fleming:

Answer 2

Discovered abx- penicillin

Question 3

Gerhard Domagk:

Answer 3

Discovered sulfanilamide- 1st practical antimicrobial

Question 4

2 chemotherapeutic/antimicrobial agents:

Answer 4

Antibiotics- used as medicine against bacteria, protozoans, fungi
Antibacterials- soaps, disinfectants

Question 5

How is an antimicrobial more toxic to pathogens than humans?

Answer 5

• Differences in structure or metabolism
• Different metabolic pathways in bacteria compared to human cells
• Protozoa, fungi, and worms are more similar to humans so they are more difficult to cure

Question 6

Broad spectrum antibiotic:

Answer 6

Works against many types and good when the bug is unknown

Question 7

Narrow spectrum antibiotic:

Answer 7

Good against a small number of germs and good when the bug is known

Question 8

3 side effects to antibiotics:

Answer 8

1. Toxicity
2. Allergies
3. Disruption of normal flora

Question 9

Toxicity effect to abx:

Answer 9

-Possible damage to organs, kidney, liver, teeth

Question 10

Allergic effect to abx:

Answer 10

Anaphylactic shock

Question 11

Disruption of normal flora effect to abx:

Answer 11

Superinfections- commensals killed, replacement flora moves in

Question 12

6 mechanisms of action:

Acronym

Answer 12

1. Inhibition of cell wall synthesis
2. Disruption of cell membranes
3. Inhibition of protein synthesis
4. Inhibition of nucleic acid synthesis
5. Inhibition of metabolic pathways
6. Inhibition of host recognition and attachment `

Question 13

Inhibition of cell wall synthesis:

Answer 13

• Selective against some bacteria and fungi

- B-lactam ring

Question 14

Disruption of cell membranes:

Answer 14

• Selective against some bacteria and fungi

- Binds phospholipids

Question 15

Inhibition of protein synthesis: (abx that inhibit protein synthesis)

Answer 15

• Aminoglycosides
• Tetracyclines
• Macrolides

Question 16

Inhibition of nucleus acid synthesis:

Answer 16

A.) Blocks DNA replication or prevents transcription to RNA, toxic to host
B.) Nucleotide analogs- non-functional molecules similar to A, T, C, G, or DNA

Question 17

Inhibition of metabolic pathways:

Answer 17

A. Competitive inhibition of enzymes- Sulfanilamides

B. Molecular mimicry

Question 18

Inhibition of host recognition and attachment:

Answer 18

Attachment antagonists

Question 19

B-lactam ring:

Answer 19

Disrupts enzymes needed to cross-link peptidoglycans

Question 20

2 ways microbes develop resistance:

Answer 20

1. Chromosomal genes

2. Extra-chromosomal genes- plasmids

Question 21

5 mechanisms of resistance:

Answer 21

1. Producing new enzymes that deactivate abx
2. Altering the cell membrane to prevent drug entry
3. Altering drug’s target to prevent binding
4. Altering cell’s metabolic pathways
5. Pumping drug out of the cell

Question 22

Disinfection:

Answer 22

Reduce number of microbes to safe levels

Question 23

Sterilization:

Answer 23

Removal of all microbes on an object

Question 24

Disinfectants:

Answer 24

Agents applied to inanimate objects

Question 25

Antiseptics:

Answer 25

Kills microbes on external surface of living tissue

Question 26

Sanitizer:

Answer 26

- Disinfects food equipment and utensils | - Can be soap and water

Question 27

Effectiveness of chemical agents is influenced by: (6)

Answer 27

1. Time 2. Temp 3. pH 4. Concentration 5. Number of organisms 6. Types of organisms

Question 28

Time effectiveness in chemical agents:

Answer 28

Length of exposure

Question 29

Bacteriostatic agent:

Answer 29

Inhibits growth of microbes, but doesn't kill them

Question 30

5 ways to limit drug resistance:

Answer 30

1. Patient must finish rx- stopping early lets resistant strains multiply 2. Synergism: additive effect of 2 different drugs - penicillin damages wall, lets streptomycin enter more easily 3. Use drugs for serious cases only 4. Continue to develop second or third generation semisynthetic drugs 5. Limit antimicrobial use in farm animals

Question 31

Temp effectiveness in chemical agents:

Answer 31

Increased temp= faster death rate, doubles with every 10 C increase

Question 32

pH effectiveness in chemical agents:

Answer 32

Affects ability to penetrate the cell

Question 33

Concentration effectiveness in chemical agents:

Answer 33

``` High= bacteriocidal Low= bacteriostatic ```

Question 34

Types of organisms effectiveness in chemical agents: (4)

Answer 34

A. Species variability B. Growth phase variability C. Most susceptible period D. Endospores

Question 35

2 mechanisms of action of chemical agents attacking cell component:

Answer 35

1. Protein denaturation | 2. Membrane sufactants

Question 36

Bacteriocide:

Answer 36

Kills bacteria specifically, not spores or fungi

Question 37

Protein denaturation:

Answer 37

- Hydrogen and disulfide bonds disrupted - Shape altered - Function lost - Ex: Alcohol, acids, strong bases, halogens, heavy metals

Question 38

Membrane surfactants:

Answer 38

Dissolve lipids, alcohols, detergents

Question 39

Germacide, microbicide:

Answer 39

Kills germs in general

Question 40

Host microbe interactions Symbiosis: (3)

Answer 40

1. Mutualism 2. Commensalism 3. Parasitism

Question 41

Host microbe interactions Normal (indigenous microflora): (3)

Answer 41

1. Resident flora 2. Transient flora 3. Opportunists

Question 42

Viricide:

Answer 42

Agent inactivates viruses

Question 43

Fungacide:

Answer 43

Agent that kills fungi

Question 44

Sporocide:

Answer 44

Agent that kills bacterial or fungal spores

Question 45

Host microbe interactions Contamination, infection, disease: (5)

Answer 45

1. Colonization 2. Contamination 3. Infection 4. Infestation 5. Disease

Question 46

Resident flora:

Answer 46

Microbes that are always present, mouth, nose, throat, intestines

Question 47

Transient flora:

Answer 47

Occur under certain temporary conditions, may last hours or months

Question 48

Opportunists:

Answer 48

Residents that can cause disease under some conditions: A. transfer of normal flora to unusual body site B. disruption of normal flora C. immunocompromised- failure of normal immune system

Question 49

Colonization:

Answer 49

Microbes appear and grow on surfaces, skin, and mucous membranes

Question 50

Contamination:

Answer 50

Unwanted microbes are present, inanimate objects, media, skin surface

Question 51

Infection:

Answer 51

Invasion, multiplication of microbes in or on host

Question 52

Infestation:

Answer 52

Multiplication of arthropods or worms

Question 53

Disease:

Answer 53

Infection leads to disruption of normal functioning- diminished health