Micro control growth Flashcards Preview

Microbiology > Micro control growth > Flashcards

Flashcards in Micro control growth Deck (22)
Loading flashcards...
2
Q

Sterilization

A

destruction of all microbes

3
Q

Aseptic

A

environment free of pathogens

4
Q

Disinfection

A

destroy most microorganisms and viruses on nonliving material

5
Q

Antiseptic

A

removal of pathogens from living tissue (not as damaging)

6
Q

Pasteurization

A

heat to remove pathogens and spoilage microorganisms; goal is to kill the pathogens that would grow at physiological temp

7
Q

Bacteriostatic

A

to inhibit the growth of bacteria, eg refrigeration

8
Q

Bacteriocidal

A

kill bacteria

9
Q

UV light bacteriostatic or bacteriocidal?

A

bacteriocidal (works best on replicating cells)

10
Q

Modes of action

A

Alteration of cell walls or cytoplasmic membranes, Interference with protein and nucleic acid structure

11
Q

Factors affecting efficacy of antimicrobial methods

A

Nature of site to be treated (living tissue, surgical instruments); Degree of susceptibility of microbes involved (study killing of major pathogens); Environmental conditions that pertain

12
Q

Evaluating disinfectants and antiseptics

A

Phenol Coefficient; Use-Dilution Test; Disk-Diffusion Method; In-Use Test

13
Q

Phenol Coefficient

A

evaluate compared to phenol

14
Q

Use-Dilution Test

A

different dilutions at different times

15
Q

Disk-Diffusion Method. Can we always be sure that a particular compound has no effect?

A

Plate bacteria, place a paper with disks on it, measure zone of inhibition. If it doesn’t diffuse it won’t produce a result (high molecular weight of material)

16
Q

In-Use Test

A

swab before and after use of chemical

17
Q

Physical methods. Think of how each works

A

Extremes of heat, Extremes of cold (inhibit), Desiccation, Filtration, Osmotic pressure, Radiation. Look at the table 9.4! Know the action!

18
Q

Thermal death point

A

lowest temperature that kills all cells (of one strain) in broth in 10 minutes

19
Q

D (decimal reduction time) value

A

exposure time at a given temperature needed to reduce the number of viable microorganisms by 90%, then 90% of 10%, then 90% of 1%, etc.

20
Q

Canning food

A

Uses D value to kill

21
Q

What’s the ultimate test to see if a sterilization technique works?

A

Use a bacteria that likes to grow at high temp (55C) and produces spores and see if it dies

22
Q

Filtration

A

used when purifying something that is heat sensitive (ie antibiotic wouldn’t tolerate heat); filters have holes of .1 µm

23
Q

Chemical methods

A

affect cell walls, membranes, proteins, and DNA, almost always denatures proteins; effects vary with time, temp, [ ], etc.