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Microbiology summer 2015 Midterm 1 > Microbial Control chapter 6 Cont. LECTURE 4 > Flashcards

Microbial Control chapter 6 Cont. LECTURE 4 Flashcards

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1
Q

Difference between biospheres and endospores:

Biosphere: _____________

Endospore: ________________ in a cocoon and is resistant to many factors

A

1) community
2) DNA is wrapped up

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2
Q

Types of microbial control

  • _______________: kill or remove all forms of microbial life
A

1) Sterilization

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3
Q

Types of microbial control

  • _______________: substances that are applied to non-living objects to destroy microbes living on them.
A

Disinfection

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4
Q

Types of microbial control

  • ______________: antimicrobial substances that are applied to living tissue or skin to reduce the possibility of infection, sepsis, or putrefaction.
A

Antiseptics

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5
Q

Types of microbial control

  • _________________: antimicrobial substance generally transported through lymphatic system to destroy microbes, bacteria towards the body.
  • May be natural, semisynthetic, or synthetic
A

Antibiotics

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6
Q

Types of microbial control

  • _________________: reduce number of targeted pathogenic organisms to acceptable levels
A

Sanitization

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7
Q

Control may be…

______________ – kill bacteria

______________ – slow bacterial growth

A

1) Bactericidal
2) Bacteriostatic

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8
Q

Rate of Microbial Death

  • Important to know rate to __________________ for disinfection
  • Want to know ______________ needed to achieve acceptable level of sterilization for a specific purpose
A

1) develop standard protocols
2) minimum time

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9
Q

Mechanisms of Microbial Control

  • Alteration of ____________________
    • Create pores in outer membrane that __________________ and disrupt membrane integrity
  • Damage __________ (structure or enzymes) and ____________
A

1) membrane permeability
2) increase permeability
3) protein
4) nucleic acid

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10
Q

Selection of Microbial Control Methods

  • Inexpensive, ____________, stable during storage, _____________.
A

1) fast-acting
2) selectively toxic

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11
Q

Selection of Microbial Control Methods

Relative resistance of microbes

  • ____________ are most resistant
    • Killed by alkylating agents, 10% bleach, proper boiling conditions, prolonged exposure to ionizing radiation
  • _____________ – difficult to treat due to cell wall
    • Antibiotic resistance is a problem
  • _____________– can survive harsh conditions allowing for transmission from host to host
  • _____________ – high resistance to some antibiotics due to efflux pumps
A

1) Endospores
2) Mycobacterium
3) Protozoa cysts
4) Gram-negatives

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12
Q

Selection of Microbial Control Methods

Site to be Treated

  • ____________ chemicals and extreme heat cannot always be used
  • Invasive devices need ________________ of treatment than noninvasive ones
A

1) Harsh
2) different level

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13
Q

Selection of Microbial Control Methods

Environmental conditions

  • _______________ and _______ affect microbial death rates and efficacy of antimicrobial methods
  • Organic materials interfere with penetration of heat, chemicals, and some forms of radiation, and may _____________ chemical disinfectants
A

1) Temperature
2) pH
3) inactivate

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14
Q

Evaluating Disinfectants and Antiseptics

Phenol coefficient

  • Compares a given agent’s ability to __________________ to that of phenol under standardized conditions
  • Greater than _____ indicates it’s more effective than phenol
A

1) control microbes
2) 1.0

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15
Q

Evaluating Disinfectants and Antiseptics

Use-Dilution Test

  • Metal cylinders are dipped in bacteria cultures, dried, then each dipped in different dilution of disinfection.After incubation, the highest dilution that prevented microbial growth is _______________
A

most effective

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16
Q

Evaluating Disinfectants and Antiseptics

In-Use Test

Swabs are taken from actual objects before and after treatment with disinfectant, then ________________ medium

A

1) incubated in appropriate

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17
Q

Physical Methods of Control

  • Thermal Death Point – _______________________________________
  • Thermal Death Time – _______________________________________
  • Decimal reduction time (D) – ____________________________________
  • Moist Heat
A

1) lowest temp that kills all cells in a broth in 10 minutes
2) the time it takes to completely sterilize a particular volume of liquid at a set temp
3) time required to destroy 90% of microbes in a sample

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18
Q

Moist Heat

  • Denatures proteins and destroys __________________.
  • More effective than _____________ (water better conductor of heat)
A

1) cytoplasmic membranes
2) dry heat

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19
Q

Kills vegetative cells of bacteria and fungi, trophozoites of protozoa, and most viruses within 10 minutes

A

Boiling

20
Q

Achieves true sterilization

A

Autoclaving

21
Q
  • Used to kill pathogens in milk, ice cream, yogurt, and juices
  • Thermoduric and thermophilic prokaryotes survive
A

Pasteurization

22
Q
  • Flash heating milk and other liquids to rid of all living microbes
  • 140C for 1-3 seconds, followed by rapid cooling
  • Indefinite storage at room temp
A

Ultrahigh-temperature sterilization

23
Q
  • Powders and oils that cannot be sterilized by boiling or steam or materials damaged by repeated exposure to steam
  • Requires higher temp for longer times than moist heat
  • 171C for 1 hour or 160C for 2 hours
  • Incineration
A

Dry Heat

24
Q

Refrigeration and Freezing

  • Decrease ________________, ________, and reproduction (except psychrophilic microbes)
  • Listeria and Yersinia (blood)
A

1) microbial metabolism
2) growth

25
Q

Desiccation and Lyophilization

Desiccation – ____________

Lyophilization – _________________

A

1) drying
2) freezing and drying

26
Q

Use high concentrations of salt or sugar to desiccate cell

Fungi have greater ability to tolerate hypertonic environments than bacteria

A

Osmotic pressure

27
Q

Disrupts the structure of DNA

A

Radiation

28
Q

Physical Methods of Control

LIST ALL SIX OF THEM

A

Heat
Refrigeration and Freezing
Desiccation and Lyophilization
filtration
Osmotic pressure
Radiation

29
Q

Chemical Methods of Control

Phenol and Phenolics

  • Intermediate- to low-level disinfectants that Denature __________ and disrupt cell membranes
  • May be modified to enhance _____________ action
  • Pine and clove oil are natural phenolic antiseptics (TEST QUESTION)
A

1) proteins
2) antimicrobial

3)

30
Q

Chemical Methods of Control

Phenol and Phenolics

  • Bisphenolics – 2 linked phenolics
    • __________________ (Lysol)
    • ___________
  • Effective in presence of contaminating ___________ materials
  • Disagreeable odor and possible side effects (skin irritation)
    • _________________ – causes brain damage in infants
A

1) Orthophenylphenol
2) triclosan
3) organic
4) Hexachlorophene

31
Q

Chemical Methods of Control

Alcohols

  • Bactericidal, fungicidal, virucidal (enveloped)
    • Intermediate-level disinfectants that denature proteins and disrupt _______________
A

cytoplasmic membranes

32
Q

Chemical Methods of Control

Alcohol

  • More effective when __________ (denaturation requires water)
  • Quick evaporation leaves no residue, but may not contact ___________ long enough to be effective
    • Pre-injection swabbing more physical removing (degerming)
A

1) diluted
2) microbes

33
Q

Chemical Methods of Control

Halogens

  • Intermediate-level disinfectants; mechanism not completely understood
  • Effective against ________________ and fungal cells, fungal spores, some bacterial endospores and protozoan cysts, and many viruses
A

1) vegetative bacterial

34
Q

Chemical Methods of Control

Halogens

  • Iodine
    • iodine tablets to disinfect water no longer thought good b/c _________ survive.Filtration is a better idea
    • tinctures or iodophors slowly release iodine.Ex) __________
  • chlorine
  • bromine
    • used in hot tubs b/c it evaporates more slowly than __________ at high temp
  • fluorine (as fluoride)
A

1) protozoan cysts
2) betadine
3) chlorine

35
Q

Chemical Methods of Control

Oxidizing agents

  • High-level disinfectants and antiseptics that oxidize enzymes to ________________
  • Particularly effective against ______________ microbes (deep puncture wounds)
  • Hydrogen peroxide
A

1) prevent metabolism
2) anaerobic

36
Q

Chemical Methods of Control

Oxidizing agents

  • ______________ – sometimes used for drinking water (Canada, Europe)
    • More effective than chlorine, but expensive and harder to maintain effective concentration
  • ______________ – effective sporicide
    • Food processors and medical personnel use to sterilize equipment
    • Not adversely affected by organic contaminants, leaves no toxic residue
A

1) Ozone
2) Peracetic acid

37
Q

Chemical Methods of Control

Surfactants

  • Reduce surface tension of solvents by ________________ the attraction among molecules
  • Soaps
    • One end hydrophobic, the other hydrophilic
    • Hydrophobic end break up oily deposits into tiny droplets
    • Hydrophilic ends attract water molecules
    • Tiny droplets of oily material harbor bacteria and are easily dissolved and washed away by water
    • Good degerming agent, but poor antimicrobial
A

1) decreasing

38
Q

Chemical Methods of Control

Surfactants

  • Detergents
    • Positively charged _____ surfactants, more soluble in water than soaps
    • Quaternary ammonium compound (quats)
    • Ammonium cation (NH4+) disrupt cell membranes so cells lose essential internal ions
    • Bactericidal, fungicidal, virucidal (enveloped)
    • Colorless, tasteless, harmless to humans, but action retarded by organic contaminants, and deactivated by soaps
    • P. aeruginosa thrives in quats
    • Low-level disinfectant
    • Zephiran, Cepacol, mouthwashes that foam
A

organic

39
Q

Chemical Methods of Control

Heavy Metals

  • Combine with sulfur atoms in molecules of cysteine to denature proteins
  • _______-level bacteriostatic and fungistatic
  • Not used much anymore
  • Used to use 1% silver nitrate to preven blindness by N. ______________ in newborns.Now use less irritating and broader spectrum agents
A

1) Low
2) gonorrhoeae

40
Q

Chemical Methods of Control

Heavy Metals

  • Sill used in some surgical dressings, burn creams, and catheters
  • Thimerosal (mercury-containing compound to preserve vaccine) was largely replaced after US Public health Service recommended safer alternatives in 1999
    • Whole-cell pertussis, some __________ against tetanus, flue and meningococcal meningitis still contain thimerosal
  • Copper interferes with chlorophyll. Used to control algal growth in reservoirs, fish tanks, swimming pools, water storage tanks
A

vaccines

41
Q

Chemical Methods of Control

Aldehydes

  • ________________ (liquid form) and ______________ (gaseous form) are highly reactive chemical
    • 2% solution of glutaraldehyde kills bacteria, viruses, and fungi.10 minutes exposure disinfects most objects in clinical settings; 10 hours sterilizes
  • 37% formaldehyde in water (formalin) is used for embalming and disinfecting isolation rooms, exhaust cabinets, surgical instruments, and reusable kidney dialysis machines.
    • Irritating to __________ membranes and carcinogenic
  • Denature proteins and inactivate _______________
A

1) Glutaraldehyde
2) formaldehyde
3) mucous
4) nucleic acids

42
Q

Chemical Methods of Control

Gaseous Agents

  • Items that cannot be treated with _________ or ________(heart-lung machine components, sutures, plastic laboratory ware, mattresses, pillows, artificial heart valves, catheters, electronic equipment, dried or powdered foods
  • Ethylene oxide, propylene oxide, beta-propiolactone
A

1) liquids or heat

43
Q

Chemical Methods of Control

Gaseous Agents

  • Penetrate paper and plastic wraps and diffuse into every crack to denature _________ and __________.
  • NASA uses _______________ to sterilize spacecrafts.Large hospitals use to sterilize heat sensitive instruments and equipment
  • Extremely hazardous to people, highly explosive, extremely poisonous (must flush with air to remove all traces), potentially carcinogenic
A

1) proteins
2) DNA
3) ethylene oxide

44
Q

Chemical Methods of Control

Enzymes

  • Lysozyme in human tears digests ______________ cell walls
  • Prionzyme approved by EU in 2006
A

peptidoglycan

45
Q

Chemical Methods of Control

Antimicrobials

  • _____________, semisythetics, synthetics
A

Antibiotics

46
Q

Chemical Methods of Control

LIST ALL 10 OF THEM

A

1) Phenol and Phenolics
2) Alcohols
3) Halogens
4) Oxidizing agents
5) Surfactants
6) Heavy Metals
7) Aldehydes
8) Gaseous Agents
9) Enzymes
10) Antimicrobials

Microbiology summer 2015 Midterm 1 (4 decks)

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