Control of Microbial Growth

A set of practice flashcards covering key concepts of microbial growth control based on lecture notes.

What is antisepsis?

Reduction in the number of microorganisms and viruses on living tissue.

Give an example of antiseptic use.

Use of iodine or alcohol to prepare skin for an injection.

What is the definition of aseptic?

An environment or procedure free of pathogenic contaminants.

What does the suffix -cide indicate?

The destruction of a type of microbe.

Define degerming.

Removal of microbes by mechanical means.

What is disinfection?

Destruction of most microorganisms and viruses on nonliving tissue.

What does pasteurization achieve?

Destroys pathogens and reduces spoilage microorganisms in foods and beverages.

Describe sanitization.

Removal of pathogens from objects to meet public health standards.

What does the suffix -static refer to?

Inhibition but not complete destruction of a type of microbe.

Define sterilization.

Destruction of all microorganisms and viruses in or on an object.

What is microbial death?

Permanent loss of reproductive ability under ideal environmental conditions.

What is the relationship between microbial death rate and conditions?

It is often constant for a microorganism under a particular set of conditions.

How do antimicrobial agents act?

They alter cell walls and membranes or disrupt metabolism and reproduction.

What happens when cell walls are damaged?

Cells burst because of osmotic effects.

What is the primary action of nonenveloped viruses?

They have greater tolerance of harsh conditions.

What can extreme heat or certain chemicals do to proteins?

They denature proteins.

What does moist heat do in microbial control?

Disinfects, sanitizes, sterilizes, and pasteurizes.

What is autoclaving?

Using pressure applied to boiling water to prevent steam from escaping.

What is the flash pasteurization temperature?

72°C for 15 seconds.

At what temperature does pasteurization of milk occur?

63°C for 30 minutes.

What is one effect of high temperatures on microbes?

Denature proteins and disrupt the integrity of membranes.

What is desiccation?

Drying that inhibits growth due to the removal of water.

What does filtration achieve in microbial control?

Physical separation of microbes from air and liquids.

What is the role of HEPA filters?

They provide high-efficiency particulate air filtration in biological safety cabinets.

What factors affect the efficacy of antimicrobial methods?

Environmental conditions such as temperature and pH.

What does lyophilization do?

Used for long-term preservation of microbial cultures.

How does osmotic pressure inhibit microbial growth?

High concentrations of salt or sugar draw water out of microbial cells.

What type of radiation is ionizing radiation?

Wavelengths shorter than 1 nm that eject electrons from atoms.

What is UV radiation primarily used for?

Disinfection of air, transparent fluids, and surfaces.

How do phenols work as antimicrobial agents?

They denature proteins and disrupt cell membranes.

What are surfactants?

‘Surface active’ chemicals that reduce the surface tension of solvents.

What is the primary action of alcohols as disinfectants?

Denature proteins and disrupt cytoplasmic membranes.

What do aldehydes do in microbial control?

Cross-link functional groups to denature proteins and inactive nucleic acids.

What defines a heavy metal as an antimicrobial agent?

Heavy-metal ions denature proteins and can be bacteriostatic.

What do oxidizing agents accomplish?

They kill microbes by oxidation of microbial enzymes.

Describe the action of gaseous agents.

Denature proteins and DNA by cross-linking functional groups.

What is the use of enzymes in microbial control?

They act against microorganisms and can digest cell walls of bacteria.

What are quats?

Quaternary ammonium compounds that act as low-level disinfectants.

What do phenol coefficients measure?

The efficacy of disinfectants by comparing their effectiveness to phenol.

What is the use-dilution test?

Evaluates disinfectant efficacy by examining growth after exposure.

What characterizes the in-use test?

Swabbing surfaces before and after disinfectant application to check for bacterial growth.

What is the purpose of conducting bacterial culture analysis?

To identify the source of infection in patients.

What were the symptoms experienced by Marcella in the scenario?

Low fever, abdominal cramps, and diarrhea.

What was suspected to be the source of Marcella's sickness?

Raw cheese from Johnson’s Dairy.

What microbial pathogen was identified in Marcella's stool sample?

Campylobacter jejuni.

Why do health officials request cessation of product sales from food vendors?

To prevent further outbreaks and identify the source of contamination.

Why are Bacillus endospores used as sterility indicators?

They are exceptionally resistant to sterilization methods, ensuring effectiveness.

What is one recommendation regarding household cleanliness?

A little dirt is okay; outdoor play can help train the immune system.

How can pets contribute to children's immunity?

Dogs and cats may reduce allergy risk through early exposure.

What is the primary action of using heavy metals in microbial control?

They denature proteins to exert bacteriostatic effects.