PT2 Unit 3.Section 1. Chapter 13: Control of Microbial Growth

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Which organism or structure is the most resistant to microbial control methods?

Hyphae

Fungal spores

Naked viruses

Prions (correct)

What chemical agent is typically used in cold sterilization?

Hydrogen peroxide

Glutaraldehyde (correct)

Chlorine

Ethylene oxide

Which factor does not affect bacterial growth?

Nutrients

HEPA filters (correct)

Temperature

What is the germicidal wavelength of UV light?

265 nm Signup and view all the answers

Which physical method of microbial control uses gamma rays?

Ionizing radiation Signup and view all the answers

The minimum temperature at which all organisms are killed in a set time is referred to as:

Thermal death point Signup and view all the answers

What is the mechanism of action for phenolics?

Disrupts membranes and denatures proteins Signup and view all the answers

What term describes the protocol that reduces microbes on living tissue using mild chemicals and scrubbing?

Degerming Signup and view all the answers

Which chemical agent can disrupt membranes and denature proteins?

Alcohols Signup and view all the answers

What term refers to the killing of microbes on non-living surfaces?

Disinfection Signup and view all the answers

What is the primary function of lyophilization in microbial control?

Dehydrating and preserving biological samples Signup and view all the answers

How does glutaraldehyde act over time to achieve sterilization?

Requires a minimum of 10 hours for spores Signup and view all the answers

Which type of radiation is preferred for sterilizing medical items due to its ability to penetrate and alter molecular structures?

Gamma radiation Signup and view all the answers

What is the main chemical mechanism behind the efficacy of phenolics in microbial control?

Disrupting membrane integrity Signup and view all the answers

Which of the following statements accurately describes the action of refrigeration on microbes?

It induces dormancy in most pathogens Signup and view all the answers

What role does HEPA filtration play in infection control?

Trapping airborne particles and microorganisms Signup and view all the answers

Which of the following statements is true regarding autoclave tape?

It provides chemical feedback during the sterilization process Signup and view all the answers

Which chemical is incorrectly associated with its typical use in acne treatment?

Formaldehyde Signup and view all the answers

What does a substance containing the suffix '-cide' imply?

Killing microorganisms effectively Signup and view all the answers

Which of the following statements about prions is correct?

Prions are resistant to most microbial control methods Signup and view all the answers

What is the role of HEPA filters in microbial control?

To physically remove particles and microorganisms from air Signup and view all the answers

In microbial control, what is the significance of the decimal reduction time?

It measures the time required to kill 90% of the organisms at a specific temperature Signup and view all the answers

Which of the following mechanisms is primarily responsible for the action of alcohols as disinfectants?

Denaturation of proteins and disruption of membranes Signup and view all the answers

What distinguishes the phenol coefficient in disinfectants?

It indicates the relative effectiveness compared to phenol Signup and view all the answers

What is the main advantage of lyophilization compared to other preservation methods?

It preserves molecular structure by rapid freezing Signup and view all the answers

What is the principle behind using ethylene oxide for microbial control?

It acts as a potent alkylating agent that disrupts DNA Signup and view all the answers

Which statement best describes the action of ionizing radiation in microbial control?

It causes direct damage to DNA, leading to mutations and cell death Signup and view all the answers

What is the primary effect of refrigeration on microbial populations?

It slows down metabolic processes significantly Signup and view all the answers

Which of the following statements about HEPA filters is true?

They trap airborne particles and microorganisms effectively Signup and view all the answers

What is the primary outcome of effective disinfection protocols?

Reduction of microbial load to safe levels for health Signup and view all the answers

What time frame does glutaraldehyde require to effectively kill spores?

10 hours Signup and view all the answers

Which property is vital for a disinfectant to have high efficacy?

Rapid action against a broad spectrum of pathogens Signup and view all the answers

What defines sanitization in the context of microbial control?

Reducing the microbial load to safe levels but not necessarily eliminating all Signup and view all the answers

Which type of radiation is used to sterilize most medical items due to its high penetration ability?

Gamma radiation Signup and view all the answers

What does a substance with '-cide' in its name primarily indicate?

It kills specific types of microorganisms Signup and view all the answers

What is the main purpose of incineration in microbial control?

Destroy waste by burning substances to ashes Signup and view all the answers

Which statement reflects the correct action of phenolics in microbial control?

They denature proteins and disrupt membranes Signup and view all the answers

Which chemical is commonly used in acne treatments due to its antibacterial properties?

Benzoyl peroxide Signup and view all the answers

Which of the following statements about non-ionizing radiation is accurate?

It includes UV light which can cause DNA mutations Signup and view all the answers

Study Notes

Microbial Control Methods

Microbial Resistance: Prions are highly resistant to microbial control methods.
Autoclave Function: Autoclaves sterilize heat-stable equipment.
Ionizing Radiation: Gamma rays are a type of ionizing radiation used in microbial control.
UV Light Germicidal Wavelength: UV light's germicidal wavelength is 200 nm.
Fomite Definition: A fomite is an object that transmits disease.
Degerming: Degerming is reducing microbes on living tissue using mild chemicals and scrubbing.
Cold Sterilization Agent: Glutaraldehyde is a cold sterilization agent.
Factors Affecting Bacterial Growth: HEPA filters do not affect bacterial growth; temperature, nutrients, and pH do.
Thermal Death Time: Thermal death time is the minimum temperature at which all organisms are killed in a set time.
Decimal Reduction Time: Decimal reduction time is the time to kill 90% of a bacterial population.
Mechanism of Action for Phenolics: Phenolics disrupt membranes and denature proteins.
Microbial Death Curve Use: Microbial death curves monitor disinfection progress.
Airborne Organism Collection: HEPA filters are used to collect organisms from air samples.
Membrane Disruption Agent: Alcohols are known for disrupting membranes.
Killing Microbes on Non-living Surfaces: Disinfection is the killing of microbes on non-living surfaces.
Disinfectant Effectiveness: A phenol coefficient of 1.2 indicates a disinfectant more effective than phenol.
Lyophilization: Lyophilization involves rapid freezing under vacuum.
Refrigeration's Effect on Microbes: Refrigeration slows microbial metabolic activity, not kills them.
Acne Treatment Chemical: Benzoyl peroxide is commonly used in acne treatments.
HEPA Filter Function: HEPA filters trap particles, spores, and microorganisms from air.
Glutaraldehyde Spore Killing Time: Glutaraldehyde takes hours, not minutes, to kill spores.
Sterilizing Radiation: Gamma radiation alters molecular structures to sterilize items.
"-Cide" Meaning: "-cide" in a substance's name means it kills microbes.
Incineration Purpose: Incineration destroys waste by burning it to ashes.
Physical Methods of Microbial Control: Some examples of physical methods include lyophilization and incineration.
Prions Resistance: Prions are resistant to microbial control methods (most resistant to control).
Refrigeration Effect: Refrigeration slows, not stops, microbial metabolism.
Pasteurization Definition: Pasteurization is a method preventing food spoilage.
Use-Dilution Tests: Use-dilution tests measure disinfectant effectiveness.
Autoclave Tape Function: Autoclave tape changes color to indicate successful sterilization.
Phenolics Mechanism: Phenolics denature proteins and disrupt membranes.
Formaldehyde Use: Formaldehyde isn't commonly used in acne treatment. UV sterilizes by causing DNA damage.
Non-Ionizing Radiation: Non-ionizing radiation does not include gamma rays.
Disinfectant Safety: A good disinfectant is typically non-toxic to humans and animals.
Most Resistant Organism: Prions are the most resistant to microbial control methods.
Germicidal UV Wavelength: The germicidal wavelength of UV radiation is 200nm, causing DNA damage and sterilizing pathogens.
Gamma Rays Sterilizing Agent: Gamma rays are an example of ionizing radiation, sterilizing various items through chemical alteration of molecules.
UV Light Type: UV light is a type of non-ionizing radiation.
Fomite's Effect: Fomites transmit disease by carrying pathogens from infected to non-infected individuals.
Degerming Action: Degerming is a process used to reduce microbial growth on living tissue.

Multiple Choice (Updated)

Organism most resistant: Prions
Autoclave purpose: Sterilizing heat-stable equipment
Gamma rays type: Ionizing radiation
UV wavelength: 200 nm
Fomite definition: Object transmitting disease
Degerming description: Reducing microbes on living tissue using mild chemicals and scrubbing
Cold sterilization agent: Glutaraldehyde
Factor affecting bacterial growth (no): HEPA filters
Minimum kill temperature: Thermal death time
90% kill time: Decimal reduction time
Phenolic mechanism: Disrupts membranes and denatures proteins
Microbial death curve purpose: Monitoring disinfection progress
Airborne organism collection: HEPA filters
Membrane disruption agent: Alcohols
Killing non-living surfaces: Disinfection
Disinfectant effectiveness (phenol coefficient): More effective than phenol
Lyophilization method: Rapid freezing under vacuum
Refrigeration effect: Slows microbial activity
Acne treatment chemical: Benzoyl peroxide
HEPA filter purpose (air): Trapping particles, spores, and microorganisms
Glutaraldehyde spore killing time: More than minutes (hours)
Sterilizing radiation mechanism: Alters molecular structures
"-Cide" meaning: Kills microbes
Incineration effect: Destroys waste by burning it to ashes
Physical control examples: Lyophilization, incineration
[remainder of multiple choice questions]

True/False (Updated)

Statement 41: Prions are very resistant (True)
Statement 42: Refrigeration slows activity, it doesn't kill (True)
Statement 43: Pasteurization prevents food spoilage (True)
Statement 44: Use-dilution tests measure disinfectant efficiency (True)
Statement 45: Autoclave tape indicates successful sterilization (True)
Statement 46: Phenolics disrupt cell membranes and proteins (True)
Statement 47: Formaldehyde isn't used in acne treatment (False)
Statement 48: UV light sterilizes by causing DNA mutations (True)
Statement 49: Gamma rays are ionizing radiation (True)
Statement 50: Disinfectants should be safe for humans and animals (True)
[remainder of true/false questions]

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge on various microbial control methods and concepts. This quiz covers topics such as autoclaving, ionizing radiation, and factors affecting bacterial growth. Understand the mechanisms of action for different sterilization agents and definitions related to microbial resistance.