The Control of Microbial Growth Part 1

62問 • 2年前

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It refers to the destruction and removal of all forms of microbial life, including endospores. And is usually done by steam under pressure or a sterilizing gas such as ethylene oxide.

Sterilization

Give one example of a sterilizing gas used for sterilization

Ethylene oxide

It refers to the use of sufficient heat treatment to kill endospores of Clostridium botulinum in canned foods.

Commercial sterilization

What endospore of an bacteria can survive but will not be able to germinate and grow under normal storage condition in commercial sterilization?

Thermophilic bacteria

it leads to the destruction of vegetative pathogens. And may make use of physical or chemical methods.

Disinfection

It leads to the destruction of vegetative state pathogens on living tissues. and the treatment is always by chemical antimicrobials.

Antiseptics

True/False: Antisepsis treatment is always by chemical antimicrobials.

True

What is destroyed during disinfection

Vegetative pathogens

Commercial sterilization treament are used to kill endospores of what microorganisms in canned foods?

Clostridium botulinum

What is used for mechanical removal in degerming?

Alcohol-soaked swab

It refers to the removal of microbes from a limited area such as the skin around the injection site. Mostly a mechanical removal by an alcohol-soaked swab.

Degerming

It is a treatment which is intended to lower microbial counts on eating and drinking utensils to safe public health levels. It can be done with a high temperature washing or by dipping into a chemical disinfectant.

Sanitation

True/False: Sanitation cannot be done with a high temperature washing or by dipping into a chemical disinfectant.

False

True/False: Bacterial population DO NOT die at a constant rate when heated or treated with antimicrobial agents.

False

For each minute the bacterial population is treated or heated with antimicrobial agents, how many of the population is killed?

90 percent

What are the factors affecting the effectiveness of antimicrobial treatments?

The number of microbes, Environmental influences, Time of exposure, Microbial characteristics

It kills microorganism primarily by coagulation of proteins (denaturation), which caused by breakage of the hydrogen bonds that hold the protein.

Moist heat

It refers to the coagulation of proteins.

Protein denaturation

It kills vegetative bacterial and fungal pathogens and almost all viruses within 10 minutes, less effective on endospores.

Boiling or flowing steam

How long does it take for a boiling or flowing stream to kill vegetative bacterial and fungal pathogens and almost all viruses?

10 minutes

This method is used in Dishes, Basins and Pitchers.

Boiling or flowing steam

What is the mechanism of Action of Boiling or flowing steam?

Protein denaturation

What are the physical methods that are used to control microbial growth?

Heat, Cold, High pressure, Desiccation, Osmotic pressure, Radiation

It is a very effective method of sterilization, at about 15 psi (121°C), all vegetative cells and their endospores are killed in about 15 mins.

Autoclaving

How long does it takes for vegetative cells and their endospores to be killed after Autoclaving?

15 minutes

What are Autoclaving used in?

Microbiological media, Solutions, Linens, Utensils, Dressings, Other items that can withstand temperature and pressure

What is the mechanism of action of Autoclaving?

Protein denaturation

It refers to the use of mild heating which is sufficient to kill the microorganisms that can cause spoilage problem without really damaging the taste of the product.

Pasteurization

What is the heat treatment for milk?

72° for 15 seconds

Pasteurization is used in what?

Milk, Cream, Certain alcoholic beverages( beer and wine)

What is the mechanism of action for Pasteurization?

Protein denaturation

It kills by oxidation effect

Dry heat

It is a very effective method of sterilization is used in Inoculating loops.

Direct flaming

It is a very effective method of sterilization that is used in paper cups, contaminated dressings, animal carcasses, bags and wipes.

Incineration

It is a very effective method of sterilization but requires temperature at 170°C for about 2 hours.

Hot-air sterilization

Where is hot-air sterilization used in?

Empty glassware, Instruments, Needles, Glass syringes

What is the mechanism of action of Direct flaming?

Burning contaminants into ashes

What is the mechanism of action of Incineration?

Burning to ashes

What is the mechanism of action of Hot-air sterilization?

Oxidation

Most filters in filtration method in use consist what?

Cellulose, Nitrocellulose

What is the mechanism of action of filtration?

Separation of bacteria from suspending liquid

The passage of a liquid or gas through a screen like materials with pores small enough to retain microbes.

Filtration

It is used to sterilize heat sensitive materials such as enzymes, vaccines and antibiotic solutions. And removes microbes by passage of a liquid or gas.

Filtration

Where is filtration method used in?

Sterilizing liquids(enzymes, vaccines) that are destroyed by heat

It has a bacteriostatic effect and is often used in food, drug and culture preservation.

Refrigeration

What is the mechanism of action of Refrigeration?

Decreased chemical reactions and possible changes in protein

It is an effective method for preserving microbial cultures, in which cultures are quick-frozen between -50°C and 95°C. And is also used in food, drug and culture preservation.

Deep-freezing

What is the mechanism of action of Deep-freezing?

Decreased chemical reactions and possible changes in protein

What is the mechanism of action of Lyophilization?

Decreased chemical reactions and possible changes in protein

In this method, water is removed by high vacuum at low temperature.

Lyophilization

It is the most effective method for long term preservation of microbial culture.

Lyophilization

It is used for the preservation of colors and nutrient values. and is often used in fruit juices.

High pressure

What is the mechanism of action of High pressure?

Alteration of molecular structure of proteins and carbohydrates.

It involves removing of water from microbes; primarily bacteriostatic. and is used in food preservation.

Desiccation

What is the mechanism of action of desiccation?

Disruption of metabolism

It results in loss of water from microbial cells and is also used in Food preservation.

Osmotic pressure

What is the mechanism of action of Osmotic pressure?

Plasmolysis

It can kill microorganism in two ways( Ionizing and Non-ionizing).

Radiation

Involves the use gamma rays or high energy electron and is not widespread in routine sterilization.

Ionizing radiation

It is used for sterilizing pharmaceuticals and medical and dental supplies.

Ionizing radiation

In this type of radiation, the radiation is not very penetrating. And is used for control of closed environment with UV lamp.

Non-ionizing radiation

Mechanism of Action of Ionizing Radiation

Destruction of DNA

Translation(Pre-finals)

MAHATHIR ALPHA · 55問 · 2年前

Translation(Pre-finals)