Term
| what is definition of antiseptic |
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Definition
| disinfectant non toxic enough to be used on skin |
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|
Term
| definition of aseptic technique |
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Definition
| procedures that minimize the chance of unwanted microbes being accidentally introduced |
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|
Term
| definition of bactericidal |
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Definition
|
|
Term
| definition of bacteriostatic |
|
Definition
| inhibit growth but does not kill bacteria |
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|
Term
| definition of disinfectant |
|
Definition
| chemical that destroys many microbes |
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|
Term
|
Definition
| elimination of most/all pathogens on a material |
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Term
|
Definition
|
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Term
|
Definition
| brief heat treatment that reduces the number of spoilage organisms and destory disease-causing microbes |
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|
Term
|
Definition
| process of inhibiting microbial growth to delay spoilage |
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|
Term
|
Definition
| a chemical that destroys all microbes |
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|
Term
|
Definition
| completely free of all viable microbes, virues, endospores - an absolute term |
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|
Term
|
Definition
| destruction or removal of all microbes through physical or chemical means |
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|
Term
|
Definition
| process to reduce number of pathogens to a safe level |
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|
Term
| does sterile indicate freedom from prions |
|
Definition
|
|
Term
|
Definition
| misfolded protein segment with no nucleic acid - not susceptile to irradiation & other methods |
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|
Term
| how do prions cause disease & and example |
|
Definition
| Prion diseases lead to brain damage when prion proteins cause abnormal clumping in the brain, CJD (mad cow) |
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|
Term
| how are prions transferred from host to host |
|
Definition
| eating of infected tissue (cannibals too) |
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|
Term
| def. of nosocomial infection |
|
Definition
| hospital/health-care acquired infections |
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|
Term
| what are 4 factors making patients susceptible to nosocomial infections |
|
Definition
| more susceptible since they are ill, invasive procedures, high concentration of pathogens, prions are hard to destroy |
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|
Term
| what are disinfection byproducts in water, and what do they cause |
|
Definition
| products of natural organic materials reacting with chlorine, bromate, trihalomethane, possibly carcinogenic |
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|
Term
| list of highly resistant microbes (5) |
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Definition
| endospores, protozoan cysts/oocytes, mycobacterium, pseudomonas, naked viruses |
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|
Term
| what species are most resistant form of life (endospores) |
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Definition
|
|
Term
| what are species of protozoan are highly resistant |
|
Definition
| Cryptosporidium parvum, Giardia lamblia - but can be killed w/ boiling |
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|
Term
| what makes mycobacterium resistant to many chemical treatments |
|
Definition
|
|
Term
| what is problematic about Pseudomonas |
|
Definition
| not only resistant to disinfectants, but some can actually grow in them |
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|
Term
| why is naked virus resistant to disinfectant and give ex. |
|
Definition
| lack a lipid envelop,so more resistant - ex. poliovirus |
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|
Term
| what are environmental conditions that make treatment more or less effective |
|
Definition
| dirt, grease, body fluids - need to clean items before sterilization |
|
|
Term
| what two key factors affect microbial death rates |
|
Definition
|
|
Term
|
Definition
| time required to kil 90% of population under specified conditions |
|
|
Term
| how does moist heat destroy microbes? |
|
Definition
| irreversibly denaturing proteins |
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|
Term
| 3 parameters when using heat for sterilization |
|
Definition
| time, temperature, pressure |
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|
Term
| what are conditions for effective autoclaving, in general |
|
Definition
|
|
Term
| what are conditions for effective autoclaving of prions |
|
Definition
|
|
Term
| what are conditions for effective boiling/treatment of drinking water |
|
Definition
| boiling at least 5 mintutes |
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|
Term
| what method used for true sterilization |
|
Definition
|
|
Term
| what is low temp pasteurization and when and when is it useful |
|
Definition
| HTST - milk treated at 72C for 15 sec |
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|
Term
| what is high temp pasteurization and when and when is it useful |
|
Definition
| UHT - milk treated at 140C for a few seconds |
|
|
Term
| what indicator used to signal effective temp reached autoclaving |
|
Definition
| Geobacillus stearothermophilllus - kept in tube, mixed with growth medium, check for culture |
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|
Term
| what is the microbe of greatest concern in canned foods |
|
Definition
| Clostridium botullinum endospores - can survive canning, germinate and produce botulinum toxin |
|
|
Term
| what is the reservoir for C. botullinum |
|
Definition
| soil, cistern water, dust, foods, honey |
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|
Term
| dry heat not as effective as moist heat, what circumstances is it used in |
|
Definition
| to destroy medical wastes & contaminated carcasses |
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|
Term
| what is equiv time needed for dry heat compared to 121 C, 15min |
|
Definition
|
|
Term
| ex where air filtration important |
|
Definition
| mycobacterium tuberculosis - in bio safety cabinets, uses continuous stream of air (negative pressure) |
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|
Term
| what bacteria are most susceptible to ionizing radiation |
|
Definition
| gram negative - salmonella, pseudomonas |
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|
Term
|
Definition
| sterilize medical equipment |
|
|
Term
|
Definition
| poor penetration & need to be actively multiplying to kill |
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|
Term
| new method for pasteurizing guac |
|
Definition
| high pressure, 130k psi -denatures proteins and alters cell permeability |
|
|
Term
| what is the only chemical sterilizing agent |
|
Definition
|
|
Term
| when is exthylene oxide used |
|
Definition
| hard to reach places, fabrics, moisture sensitive material |
|
|
Term
| what is a limitation of using ethylene oxide |
|
Definition
| toxic, explosive, carcinogenic |
|
|
Term
| advantages of using alcohol |
|
Definition
| easy to obtain, inexpensive (but evaporate quickly) |
|
|
Term
| why formaldehyde not used any more as preservative |
|
Definition
| irritating to respiratory tract, skin, eyes |
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|
Term
|
Definition
| a biguanide - stays on skin/mucous membranes, |
|
|
Term
| what is use of chlorhexidine |
|
Definition
| ingredient in mouthwashes, skin creams, disinfectants |
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|
Term
| what are the halogens & how used |
|
Definition
| disinfect with low volume, 500ppm |
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|
Term
|
Definition
| silver nitrate drops in the eyes of newborns to prevent Neissaria gonorrhoeae |
|
|
Term
| what are some problems associated with use of heavy metals |
|
Definition
| combine with sulfhydryl groups and and kill organisms |
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|
Term
| what use is made of quats |
|
Definition
| disinfect food prep surfaces, though some |
|
|
Term
| what charge does a quat carry |
|
Definition
| positive charge on hydrophillic region, is attracted to neg. charged microbial cell surface |
|
|
Term
| which products may contain triclosan or hexaclorophane & how do they work |
|
Definition
| phenolics - destroy membranes & denature proteins, |
|
|
Term
| ways to preserve perishables (3) |
|
Definition
| chemical preservatives, low temp storage, reducing available water (add sugar or salt) |
|
|
Term
| what purpose do nitrate/nitrates serve |
|
Definition
| inhibit germination of endospores, Clostridium botulinum |
|
|
Term
| which chemicals are added to prevent microbial growth |
|
Definition
| benzoic, sorbic, propionic acids |
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