Exam 2 Flashcards
What are some. Simple ways we can control microbial. Growth?
Hand washing, showers, brush teeth, wash clothes, refrigeration
Who were the major contributors to inventing ways to control microbial growth?
Semmelweis and Pasteur
What. Are hey he. 2 major types of microbial growth. Control?
Sterilization
Disinfection
What is seterilization?
How many microbes eliminated?
Destruction of ALL microbes
All human pathogens are eliminated
What is disinfection?.
Are all microbes eliminated
Use of a chemical or physical agent. To inhibit or destroy microbes on surfaces or inanimate. Objects.
Not all human pathogens. Are eliminated
What are the types of disinfection?
Antisepsis
Sanitization
Pasteurization
What. Is antisepsis?
Disinfection of. Tissue via. A. Chemical agent
Must be. Safe. To. Use on tissue
What Is sanitization?
Reduce number. Of pathogens On a surface to meet public health standards
What is pasteurization?
Use. Md heat to kill pathogens and decrease number of spoilage. Organisms,
Increases shelf life of. Food/beverages
What are the 8 things to consider when thinking to microbial growth control?
- Number of microbes- more microbes takes longer. Time to. Kill
- Duration of exposure-how long does it. Take?
- Types. Of microbes- endospore former, acid fast bacteria?
- Temperature- decreased temp molecular. Motion of molecules decreased
- Concentration of the chemical
- Ph- alkaline ph is. Harder. For microbes
- Environment- presence. Of. Organics (blood, pus, ect)- decreased accessibility, organically interfere with action of some chemicals
- Endospore formation
What are the targets/how do antimicrobial agents inhibit/kill microbes? Three ways
Alteration of membrane permeability
Denature proteins
Damage nucleic acids
How does an anti microbial agent alter membrane permeability?
Microbe burst/shrivel
Leak necessary items out of microbe
Not allow. Necessary items. Into microbe
How do antimicribial agents denature proteins?
Unfolding proteins doesn’t maintain. 3D shape, won’t function
Denature enzymes
Hw do antimicrobial agents damage nucleic Acids?
What molecules does it target?
Block DNA replication, transcription, translation
DNA and RNA
What are the 6 different kinds of physical microbial growth. Control?
Heat Cold Drying Filtration Osmotic pressure Radiation
For heat, what is the action, cost, target,time frame and types?
Denatures proteins Inexpensive Kills lots of microbes Fast Dry heat, incineration, moist heat, autoclave, pasteurization
How does time and temperature matter. With mycobacterium tuberculosis?
Higher the temperature,the shorter time of exposure:
58- 30 minutes
65-2 minutes
72-3 seconds
What is a example of dry heat? Temp and time? Does it penetrate? What can you disinfect, what can you not? Can it be a sterilizer?
Oven 160 C~2 hours No Glassware/instruments, not liquids Yes
What is a example of an incinerator?
Sterilizer?
What can you use it on?
Bacti-cinerator
Sterilizer
Must be metal and able to take extreme heat
Does moist heat penetrate?
What is a example?
Sterilization?
What microbe can survive boiling?
Yes
Boiling
Not reliable sterilization
Endospores
What takes longer or sterilize? Moist or dry heat?
Dry heat takes more time
What two physical things does autoclave combine?
What must be maintained for it to sterilize?
What can you use it on? Can’t?
When must you test it.
What is used so you can tell it was effective?
Moist heat and osmotic pressure Temp and pressure Glassware, liquids, instruments, microbial media NOT on plastics, will melt Frequently Autoclave tape
Does pasteurization sterilize? How doss it work? What is the holding method? Flash method? ultra flash method?
No, it disinfects Kills pathogens and spoilage. Organisms with heat 62.9 for 30 minutes 71.6 for 15 seconds 140 for 3 seconds
What is cold action?
Who does it work on?
Decrease growth, metabolism, reproduction
Fridge halts growth. No most human pahogens (mesophiles)
What is the action of drying?
Examples
Method example
Decrease metabolism (requires water)
Dry fruit, grains, peas, beans. Yeast
Lyophilization-removing water under vacuum
Action of filtration?
Examples
Examples of what it is used on
Pores in the filter trap microbes
Surgical masks, HEPA filters
Pharmaceuticals, vaccines, blood products
Action of osmoti. Pressure
Examples
Shrivel/burst microbe
Jam, jelly, honey
Action of radiation?
Two types
Damages DNA
Ionizing radiation
Nonionizing radiation
What rays does ionizing radiation use
What is it used on/for?
Gamma and X-rays
Preserve food
Drugs,vaccines, medical instruments
What rays do non ionizing radiation use?
Where is it used?
Uv light
Operating rooms, labs, morgues
What are. The 9 different types of chemical methods for microbial control?
Phenol and phenolics Soaps/detergents Alcohol Heavy metals Chlorine Iodine/iodophors Aldehydes Gaseous sterilizers Peroxides
How does the presence. Of organic effect the effectiveness of chemical agents?
Decreases. The. Effectiveness
What does a chemical for microbial control. Label. Usually include?
Microbes it is effective against,
Duration of exposure
Chemical agent used
What are phenols/phenolics effective against.
Action?
Gram positive bacteria and some fungi
Alter membrane permeability,denatures proteins
Who was the first to use phenol?
What are its drawbacks?
What did they do to lessen this. Problem?
Lister during surgery
It. Is toxic/caustic, and very expensive
Chemically altered no phenol. To. Produce phenolics, which is less irratibile qualities
What are phenolics used for?
Hard surface disinfectant Skin cleanser (phenolic+detergent) Throat lozenges/sprays ( antiseptic) Triclosan (tons of products) Hibiclens Clove and pine oil are phenolics,antiseptics/disinfectants
What is soap?
What is its ph?
Commonality?
Fat and lye
9-10
Very hard to find
What is detergent made of?
Why is it better than soap?
Made from petroleum products
More soluble in water
Why is a surfactant
What are some examples?
How does it work?
Surface-active agent
Soap and detergent
Decreases surface tension so things are rinsed away in water
What are soap/detergents effective against?
What is their action?
How does it do this?
What is sometimes added
Broad-range of microbes
Mechanical removal of microbes
- surfactant decreases surface tension on skin. Breaking apart oil on skin, lifts off microbes so they can be rinsed away in water.
-surfactant has a polar end and no polar end. No polar end grabs
microbe, polar end mixes with water and washed away.
Chemicals are sometimes added
How does hand washing affect infection rates in hospitals?
Decreases it by 50%
What a a alcohol affective against?
Action?
Vegetative bacteria, enveloped viruses, fungi,some Protozoa
Damages their membranes, dissolves some lipids, and denatures proteins
For alcohol to be effective what is the dilution percent? What else is needed?
What is it used as or in?
What is thproblem with it?
What is added to increase effectiveness?
70% Water Skin antiseptic, and hand sanitizer Evaporates quickly so duration of exposure sins hard to reach Detergent chemical
What are heavy metals effective against?
Action?
Three examples
Broad range of microbes
Denature proteins
Silver, mercury,and zinc
What are some things silver is used in?
Silver nitrate drops In the eyes of newborns, burn cream, wound ointment,silver impregnated catheters
What is mercury used in.
Mercurochrome(antiseptic)
Preservative
What is zinc used in?
Dandruff shampoo, some mouthwash
Chlorine is effective against? Action? Example? Most affective amount? What is it used on?
Broad range of microbes
Denatures proteins
Sodium hypochlorite (main ingredient in bleach)
10% solution
Dialysis equipment, food processing, pools
Iodine is effective against?
Action?
What is a example?
What is an iodophors? What are they used for?
Broad range of microbes
Denature proteins
Betadine- aqueous iodine for skin antiseptic
Iodine and detergent for disinfecting surfaces
Aldehydes are effective against?
Action?
3 examples?
What are aldehydes used for?
All microbes! A sterilant
Denature proteins
Formaldehyde, formaline, gluteraldehyde
Slide fixing, preserving biological specimens, embalming, dialysis equipment, respiratory therapy equipment, endoscopes, instruments
Compare formaldehyde, Formalin, and Gluteraldehyde.
Colorless gas with a pungent odor
37% solution of formaldehyde and water! expensive, smells real bad
Tweaked version of formalin/formaldehyde, less expensive, safer, smells better, and more effective
Gaseous sterilizers are eeffective against?
Action?
Example? Characteristics? What is it used for?
All microbes (sterilant)
Denatures proteins
Ethylene oxide
-must be in a closed chamber, explosive, toxic to humans, takes 1-3 hours in chamber to sterilize
-plastics, sutures, heart valves, heart-lung machines,mattress, buildings
What are peroxides?
Effective against?
Action?
What are three examples?
Oxidizing agents, they steal electrons from proetiens
Anaerobes
Oxidizing a gent, denatures proteins
Hydrogen peroxide, ozone, peracetic acid
What is hydrogen peroxide used for?
What do bubbles mean?
Want is the equation?
What is the best type of wound and why?
Skin antiseptic
There is oxygen present, means aerobic respiration is happening and hydrogen peroxide is not working
H2O2—catalase—–>2H+ + O2
Anaerobic wounds, because anaerobes don’t produce catalase so hydrogen peroxide can then denature proteins
What is ozone used for.
Paracetic acid?
Disinfect air, water/industrial settings, cooling towers
Space shuttle, probe, rover…
What are four ways that infectious disease was treated historically?
100 years ago, how many kids died before what age?
Enemas, blood curdling ice baths, deadly starvation, blood letting
1/3 of kids died before age 5
Who invented the magic bullet and what Does it do?
What did he make hundreds of compound out of?
What was his 606 compound?
Effective against what?
Why was it stopped?
Paul ehrlich Kills pathogens but not humans Arsenic-phenol Salverson Syphilis Stopped due to toxicity
Who was over the company that produced a dye called??
When tested in animals, what kind of bacteria did it inhibit?
Who was the first human he tested it on? Why?
Did it work?
Did he get a Nobel prize?
Gerhard domagk Prontosil Gram positive bacteria His daughter because she poked herself with a needle, got an infection in her arm, md was going to amputate, he injects her with prontosil It works! Yes Nobel prize!
Who discovered antibiotics?
What microbe was he originally studying?
What contaminated his streak plate? How did that contaminate affect the microbe he was studying?
What did he name the substance that inhibited growth?
Could he isolate this substance?
Alexander Fleming
Staphylococcus
Penicillium
Where penicillium grew, staphylococcus did not grow.
Penicillin
Can not isolate substance, so publishes a paper