Micro bio ch 7

What is the definition of sterilization in microbial control?

Removing all microbial life, including endospores.

What does commercial sterilization entail?

Killing Clostridium botulinum endospores.

What is the primary goal of disinfection?

Removing pathogens from inanimate surfaces.

What is antisepsis?

Removing pathogens from living tissue.

What does degerming mean?

Removing microbes from a limited area.

How does sanitization differ from disinfection?

Sanitization lowers microbial counts on eating utensils to safe public health levels.

What is bacteriostasis?

Inhibiting but not killing microbes.

What factors influence the effectiveness of microbial control agents?

Number of microbes, environment, time of exposure, microbial characteristics.

What is the effect of moist heat on microbial life?

Moist heat denatures proteins and kills microorganisms.

What does the thermal death point (TDP) represent?

The lowest temperature at which all cells in a culture are killed in 10 minutes.

What are the advantages of glutaraldehyde as a disinfectant?

It is effective against a wide range of pathogens and has a longer residual effect.

What is the purpose of use-dilution tests?

To determine the bactericidal or bacteriostatic effectiveness of disinfectants.

How does ionizing radiation damage cells?

By creating reactive hydroxyl radicals that damage DNA.

What is the role of heavy metals in microbial control?

They denature proteins and enzymes, effectively killing or inhibiting microbial growth.

Why are gram-negative bacteria more resistant to chemical biocides than gram-positive bacteria?

Gram-negative bacteria have an outer membrane that provides additional protection against biocides.

What are peroxygens, and what is their use in microbial control?

Oxidizing agents like ozone and hydrogen peroxide that are used to disinfect contaminated surfaces.

What types of microbial structures are targeted by microbial control agents?

Membrane permeability, proteins, and nucleic acids.

What does the disk-diffusion method evaluate?

The efficacy of chemical agents against microorganisms.

Which types of microbial organisms are the least resistant to control measures?

Viruses with lipid envelopes are the least resistant.

What is the significance of the term 'asepsis' in microbial control?

Asepsis refers to the absence of significant microbial contamination.

What is the role of temperature in controlling microbial growth?

Temperature can inhibit or promote growth; extreme temperatures can kill or inhibit microbes.

What is pasteurization?

A process that uses heat to reduce microbial load in food and beverages.

How do preservatives function in microbial control?

Preservatives inhibit microbial growth by interfering with metabolic processes.

What is the difference between bactericidal and bacteriostatic agents?

Bactericidal agents kill bacteria, while bacteriostatic agents inhibit their growth.

What is the importance of cleanroom environments in microbial control?

Controlled environments reduce the risk of contamination in sensitive manufacturing processes.

How does UV radiation affect microbial growth?

UV radiation damages DNA, preventing replication and leading to cell death.

What are quorum sensing inhibitors?

Compounds that disrupt the communication between bacteria, preventing biofilm formation.

How does aldehyde disinfectants work?

Aldehydes inactivate proteins and nucleic acids, effectively killing microorganisms.

What are antibiotics and how do they control microbial growth?

Antibiotics are chemicals that kill or inhibit bacterial growth specifically or broadly.

What is the significance of biofilms in microbial control?

Biofilms protect bacteria from antimicrobial agents, making them more resistant to control measures.