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Flashcards in Exam 4 Deck (26)
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0
Q

How do you measure the efficiency of a disinfectant

A
  1. Use dilution test- flask dipped in bacteria then disinfectant
  2. Filter paper method(Kirby-Bauer)- dipping paper in disinfectant then lay it over plate of bacteria
1
Q

Pasteurization is what kind of method

A

Disinfection

2
Q

Types of chemical methods of microbe control

A
  1. Phenol (lister)
  2. Bisphenols
  3. Biguanides
    4.halogens
    5 alcohols
  4. Heavy metals
  5. Detergents
3
Q

Big unaided

A

Example: chlorhexidine

Targets cell membrane but not spores
Less toxic than phenolics

Used for surgical scrubs

4
Q

Halogens

A
  1. Iodine
    Binds amino acids like tyrosine
    Effective against spores
    Antiseptic
  2. Cl2 (chlorine) (quick)
    Must combine with water
    Strong oxidizer
5
Q

Alcohols

A
  1. Don’t kill endos
  2. Denature proteins by causing cell mem probs
  3. Evans quickly
  4. Determine for shots
6
Q

Heavy metals

A
  1. Silver, mercury, copper
  2. Oligodynamic action
  3. Suffer nitrate for eye drops for new borns
  4. Silver infused stuff
7
Q

Two types of detergent by their charge

A

Anionic

Cationic

8
Q

Anionic

A

Mainly used to remove bac from surface

9
Q

Cationic detergent

A

Disrupts membrane, protein denaturing

10
Q

Organic acids

A

Damage plasma mem

Food preserves

11
Q

Aldehydes

A

Inactivates proteins

Glutoraldehyde- equipment use
Formaldehyde- embalming fluid

12
Q

Gases

A
Ethylene oxide
Denatures proteins
Kills spores 4-18 hrs
Toxic/explosive
Sterilizes
13
Q

What two characteristics do antibiotics have to exhibit to be effective treatments for bacterial infection

A

Must have:

  1. Selective toxicity (only hurt microbes)
  2. Target has to be essential
14
Q

Selective toxicity east to hard

A
Gram +.                   Easy to fight
Gram -
Fungi.                       Moderate 
Intracellular 
Viruses.                    Hard to fight
15
Q

Why are intercellular and viruses harder to fight

A

Because bacteria have walls (we don’t)which can be targeted

Intros cellular and viruses are inside put own cells

16
Q

When did Fleming discover penicillin

A

1929

Large scale production in 1940

17
Q

What did the figure out about antibiotics in 1956

A

Active against GROWING bac only (cell wall synthesis)

Poor activity against gram- bac.

Destroyed by acid

18
Q

What is penicillinase

A

Enzyme that is produced by bacteria that breaks down penicillin.

19
Q

Similar-synthetic antibiotics

A
  1. Acid resistant
  2. Less allergenic
  3. Penicillinase resistant
  4. Reach cns
  5. Active against gram - (different two chemical groups and combining them)
20
Q

Describe mersa

A

Spherical
Gm + ,
Irregular clusters like grapes

21
Q

When did antibiotics become popular

A

1940

Curing “simple” ailments

Used to save loves in ww2

22
Q

When did people start seeing resistance to antibiotics?

A

Early on so they just started using more of the drug or give them a different drug

Today, lots of resistant forms are appearing, even new ones

23
Q

How do drugs develope a resistance

A
  • microbes divide rapidly
  • because they are dividing so rapidly, errors in DNA occur causing a mutation
  • microbes can actually pass genes from one microbe to a different one
  • some of these bac have mutations that help them be antibiotic resistant
  • they survive and divide even after antibiotic
24
Q

What can resistant bacteria be compared to

A

Accelerated natural selection

25
Q

How are physicians contributing to the antibiotic resistance Orin

A

Using too many broad spectrum drugs

Using exotic drugs first