Microbial control.

97問 • 2年前

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Diseases may result from microbial infection

Germ theory of disease.

Proposed, in 1546, that seed-like “spores” may be transferred between individuals through direct contact, exposure to contaminated clothing, or through the air

Girolamo Fracastoro.

early notion of germ theory of disease

Girolamo Fracastoro.

Promoted washing of hands before medical procedures (childbirth) to prevent puerperal fever to mothers.

Ignaz Semmelweis.

Conducted studies to track the source of cholera outbreaks in London.

John Snow.

introduced aseptic surgery (he insisted on handwashing and extreme cleanliness during surgery)

Joseph lister.

began using carbolic acid as antiseptic during surgery

Joseph lister.

Developed vaccines for rabies in animals and humans

Louis Pasteur.

He was the first to demonstrate the connection between a single, isolated microbe and a known human disease

Robert Koch.

discovered the bacteria that cause: Anthrax Cholera Tuberculosis

Robert Koch.

He also developed vaccine for fowl cholera, rabies, and anthrax

Pasteur.

first to commercialized vaccine (cowpox scabs) against smallpox

Edward Jenner.

diphtheria used to be the major caused of child death until a diphtheria antitoxin was developed by von Behring

Emil von Behring.

Used to be the major caused of child death

Diphtheria.

salvarsan

Paul Ehrlich.

penicillin

Alexander Fleming.

helped in isolating penicillin subsequently won the Nobel Peace Prize with Fleming

Howard Florey & Ernst Boris Chain.

sulfanilamide (Prontosil®)

Gerhard Domagk.

streptomycin.

Selman Waksman.

The removal or destruction of ALL living microorganisms.

Sterilization.

Sufficient heat treatment to kill endospores of Clostridium botulinum in canned food.

Commercial sterilization.

In commercial sterilization what specific endospores found in canned food killed by sufficient heat treatment.

Clostridium botulinum.

Treatment is intended to lower microbial counts on eating and drinking utensils to safe public health levels

Sanitation.

Destruction of vegetative pathogens on inanimate objects

Disinfection.

Destruction of vegetative pathogens on living tissue.

Antisepsis.

meaning to kill; treatment that causes death of microorganism

-Cide.

kills microorganisms in general

Biocide or germicide.

kills fungi

Fungicide.

meaning to stop or to steady; treatment that inhibits growth and multiplication of microorganisms

Stasis.

inhibits molds

Fungistatics.

Inhibits multiplication of bacteria.

Bacteriostat.

removal of microbes from a limited area, such as the skin around an injection site

Degerming.

Indicates bacterial contamination

Sepsis.

Absences of significant contamination

Asepsis.

When bacterial populations are heated or treated with antimicrobial chemicals, they usually die at a constant rate. (True/False)

True.

The susceptibility of the plasma membrane is due to its lipid and protein components. Certain chemical control agents damage the plasma membrane by altering its permeability.

Alteration of membrane permeability.

Some microbial control agents damage cellular proteins by breaking hydrogen bonds and covalent bonds. Other agents interfere with DNA and RNA and protein synthesis.

Damage to protein and nucleic acid.

When selecting methods of microbial control, one must consider what else, besides the microbes, a particular method will affect. (True/False)

True.

This method kills spores, as well as vegetative forms of microorganisms.

Dry heat sterilization.

This is applicable for substances unaffected at a temperature of 148–260°C in the oven, at an exposure time of at least 45 minutes

Dry heat sterilization.

This method is ideal for sterilizing glassware, metalware, and anhydrous oils.

Dry heat sterilization.

The principle of sterilization involved is the oxidation of microorganisms by heat.

Dry heat sterilization.

used to sterilize inoculating instruments using alcohol lamp or burne

Direct flaming.

Burning materials to ashes

Incineration.

This is more effective than dry heat method. The principle of sterilization is the coagulation of the cell protein of the microorganism.

Moist heat sterilization.

Boiling point of water is 100°C. At this temperature, vegetative pathogens, viruses, some fungi and its spores are killed within 10 minutes.

Boiling.

What are the microorganisms killed when boiling at 100°C

Vegetative pathogens, viruses, fungi, spores.

What are the microorganisms that can't kill in boiling.

Bacterial endospores, parvovirus.

Boiling point of water at a pressure of 15 psi is 121°C. At this temperature, even endospores are killed.

Autoclave.

Exposure time are 15–30 minutes.It is the most effective method of moist heat sterilization.

Autoclave.

It uses a high temperature for a short time to neutralize the pathogens without altering the flavor of the food

Pasteurization.

at least 72°C for 15 seconds

HTST pasteurization.

at least 135°C for 2-5 seconds

UHT Sterilization.

Effective for vegetative forms of microorganisms and endospores without heating above 100°C

Fractional sterilization method.

It makes use of moist heat at 100°C, using free flowing steam.

Tyndallization

It is normally performed by 2 to 3 exposures, alternated with intervals at room temperature or incubator temperature.

Tyndallization.

Takes a few days to finish (time-consuming and outdated).

Tyndallization.

is a fractional method of sterilization at 60°C in an oven, alternated with intervals at room temperature or incubation for 2 to 3 days.

Inspissation.

The passage of liquid or gas through a filter with pores enough to retain microbes

Filtration.

Microbes can be removed from air by high-efficiency particulate air filters.

Hepa filter.

Membrane filters composed of nitrocellulose or cellulose acetate are commonly used to filter out bacteria, viruses and even large proteins.

Membrane filter.

The effectiveness of low temperatures depends on the microorganisms and the intensity of the application.

Low temperature.

Microorganisms do not reproduce at ordinary refrigerator temperatures (0–7°C)

Low temperature.

Many microbes survive (but do not grow) at the subzero temperatures used to store food.

Low temperature.

It is a non-thermal food preservation technique that kills microorganisms that can cause diseases or spoil food.

High pressure.

It uses intense pressure for a certain time and has minimal effects on taste, texture, appearance, or nutritional values

High pressure.

In the absence of water, microorganisms cannot grow but can remain viable.

Desiccation

Viruses, protozoal cysts and bacterial endospores can resist desiccation.

Desiccation.

Microorganisms in high concentrations of salts and sugars undergo plasmolysis.

Osmotic pressure.

Molds and yeasts are more capable of growing in materials with low moisture or high osmotic pressure than bacteria are.

Osmotic pressure.

Has various effects on cells, depending on its wavelength, intensity, and duration

Radiation.

This is used to aid reduction of air borne contamination produced by mercury vapor lamps. This method has poor penetration capability

Ultraviolet radiation.

Ultraviolet radiation effectiveness depends on

Length of time exposure, intensity of radiation, susceptibility of the microorganisms.

Ionization radiation is a form of energy that acts by removing electrons from atoms and molecules of materials that include air, water, and living tissue

Ionization radiation.

This radiation method makes use of high energy emitted from radioactive isotopes such as cobalt 60 (gamma rays) or by cathode or (beta rays).

Ionization radiation.

are more reliable because there is no mechanical breakdown, but it has a disadvantage of rare source and cannot be shut off immediately.

Gamma rays

are mechanical acceleration of electrons to high velocity and energy. Accelerated electrons provide higher and more uniform dose output and can destroy organisms by stopping its reproduction.

Beta particle.

Chemical agents are used on living tissue (as antiseptics) and on inanimate objects (as disinfectants). Few chemical agents achieve sterility. (True/False)

True.

The presence of organic matter, degree of contact with microorganisms, and temperature should be considered. (True/false)

True.

There is a need to evaluate the effectiveness of disinfectants and antiseptics. The current standard is the American Official Analytical Chemist’s use-dilution test.

Evaluating a disinfectant.

bacterial (S. choleraesuis, S. aureus, and P. aeruginosa) survival in the manufacturer’s recommended dilution of a disinfectant is determined.

Dilution test.

a disk of filter paper is soaked with a chemical and placed on an inoculated agar plate; a clear zone of inhibition indicates effectiveness.

Filter paper method.

Exert their action by injuring plasma membranes, inactivating enzymes, and denaturing proteins.Common phenolics are cresols and hexachlorophene.

Phenol and phenolic.

damages plasma membranes of vegetative cells.

Chlorhexidine.

(iodine and chlorine) are used alone or as components of inorganic or organic solutions.

Halogens.

Iodine is available as a tincture (in solution with alcohol) or as an iodophor (combined with an organic molecule)

Halogens.

Exert their action by denaturing proteins and dissolving lipids. In tinctures, they enhance the effectiveness of other antimicrobial chemicals

Alcohol.

Aqueous ethanol (60% to 90%) and isopropanol are used as disinfectants. (True/False)

True.

Silver, mercury, copper, and zinc are used as germicidals.They exert their antimicrobial action through oligodynamic action.

Heavy metals and compounds

Agents decrease the tension between molecules that lie on the surface of a liquid; soaps and detergents are examples.

Surface active agents.

Soaps have limited germicidal action but assist in the removal of microorganisms through scrubbing. Acid-anionic detergents are used to clean dairy equipment.

Surface active ingredient.

Quats are cationic detergents attached to NH4+ (True/False).

True.

By disrupting plasma membranes, they allow cytoplasmic constituents to leak out of the cell. They are most effective against gram-positive bacteria.

Quaternary ammonium compounds.

Sorbic acid, benzoic acid, and propionic acid inhibit fungal metabolism. They are used as food preservatives.

Organic acid and derivatives.

exert their antimicrobial effect by inactivating proteins.They are among the most effective chemical disinfectants

Aldehydes.

Ethylene oxide is the gas most frequently used for sterilization. It penetrates most materials and kills all microorganisms by protein denaturation.

Gaseous chemo sterilizers.

Ozone and peroxide are used as antimicrobial agents.They exert their effect by oxidizing molecules inside cells.

Oxidizing agent.

Cell structure.

Quinn Karylle Fuentes · 28問 · 2年前

Cell structure.