Shared Flashcard Set

Details

Ch 7
Control of Microbial Growth Continued
43
Microbiology
Undergraduate 2
07/18/2010

Additional Microbiology Flashcards

 


 

Cards

Term
chemical agents are used to
Definition
disinfect not sterilize
Term
ideal chemical disinfectant
Definition
-possess a large spectrum of antimicrobial activity
-be soluble in water or other solvent
-be stable
-be non toxic to humans and animals
-be toxic to microorganisms at room or body temp
-be able to penetrate surfaces
-be non corrosive
Term
3 factors to consider when choosing a chemical disinfectant
Definition
-nature of surface being treated
-type of microorganisms present
-environmental conditions
Term
Use-Dilution test
Definition
-metal or glass cylinder soaked into standardized cultures of the test bacteria
-removed, dried, and soaked in solution of disinfectant
-transferred to a growth medium
Term
Disk diffusion method
Definition
-disk of filter paper soaked in disinfectant
-placed on agar plate inoculated and incubated with test microorganism
Term
phenol and phenol derivatives
Definition
-first antimicrobial chemical agents ever used
-work by denaturing proteins and damaging cell membranes
-rarely used because of odor and skin damage
-present in lozenges in small concentration (local anesthetic)
-at conc above 1%, antibacterial effect
-phenolics
-bisphenols
Term
phenolics
Definition
-contain a molecule of phenol chemically altered to reduce irritation and increase antimicrobial activity
-work by damaging lipid membrane
-O-phenylphenol is the main ingredient of Lysol
Term
bisphenols
Definition
-contain two phenolic groups connected by a bridge
-hexachlorophene
-triclosan
Term
hexachlorophene
Definition
-gram + staph and streptococci
-used for surgical and hospital microbial control
Term
triclosan
Definition
-used in antibacterial soaps and at least one toothpaste
Term
biguanides
Definition
-disrupt membranes
-broad spectrum (G+, G-, enveloped viruses)
-used for microbial control on skin and mucous membranes
-present in oral rinsers and skin cleansers
Term
Halogens
Definition
-iodine
-chlorine
Term
iodine
Definition
-one of most effective antiseptics
-active against all types of bacteria, many endospores, fungi, and some viruses
-acts by disrupting protein synthesis and membranes
-allergen for some
-tincture
-iodophor
Term
tincture
Definition
iodine in solution in alcohol
Term
iodophor
Definition
-iodine with organic molecule
-example betadine
Term
chlorine
Definition
-as a gas or combined with other chemicals
-one of the most commonly used
-disinfects municipal drinking water, sewage, pools
Term
when chlorine is added to water
Definition
-forms hypochlorous acid and then hypochlorite ion
-the acid is an oxidizing agent that destroys much of cellular enzymes
Term
sodium hypochlorite
Definition
-NaOCl
-used as a bleach and household disinfectant
-used in dairies and food processing
-hemodialysis equipment
Term
chloramines
Definition
-combo of chloride and ammonia
-municipal water treatment systems (toxic to fish)
-in US military forces Chlor Floc is used to clarify water
Term
chlorine dioxide
Definition
-strong oxidizing agent
-increasing used in food processing industry as surface disinfectant
Term
alcohols
Definition
-act by denaturing proteins, damage membranes(lipid dissolution)
-ethanol
-isopropanol
Term
ethanol
Definition
-very efficient between 60-95% but do not kill endospores
-kill enveloped viruses
-pure ethanol is ineffective because proteins are more soluble and denature more easily in water
Term
isopropanol
Definition
-slightly better than ethanol
-less volatile, cheaper
Term
heavy metals and derivatives
Definition
-can be used as biocide or antiseptic at very small concentration (oligodynamic action)
-ancient Egyptians used to keep water clean by putting silver coins in water barrels
-most efficient are mercury, silver, copper
-work by denaturation, combine with sulfhydryl groups (SH)on microbial proteins
Term
silver (Ag)
Definition
-used as antiseptic in a 1% silver nitrate solution
-used to prevent newborns from getting gonorrhoea from mother
-now present in plastic food containers, athletic shirts and socks
-silver sulfadiazine is used as topical cream to treat burns
Term
Mercury(Hg)
Definition
-Mercuric Chloride
-very broad spectrum of activity
-bacteriostatic
-was sued to treat syphilis
-toxic - primarily used to control mildew in paints
Term
Copper
Definition
-copper sulfate
-used to destroy algae in reservoirs, ponds, swimming pools, fish tanks
Term
soap and detergents
Definition
-degerming rather than antiseptic
-mechanical removal of microorganisms
Term
acid anionic santizers
Definition
-anion portion reacts with plasma membrane
-used to clean dairy utensils and equipment
-wide spectrum
Term
Quaternary ammonium compounds
Definition
-derived from ammonium ion
-strong bactericidal action on G+
-very effective against fungi, amoeba, enveloped viruses
-Benzalkonium chloride (Zephiran) and Cetylpyridinium chloride (Cepacol) are
commonly found in mouthwash
Term
food preserves
Definition
-organic acids, salts of organic acids
-rapidly metabolized, safe in foods
-sulfur dioxide
-Sorbic acid, potassium sorbate, sodium benzoate
-calcium propionate
-sodium nitrate sodium nitrite
Term
sulfur dioxide
Definition
prevents wine spoilage
Term
Sorbic acid, potassium sorbate, sodium benzoate
Definition
used to prevent molds from growing on cheese and soft drinks
Term
calcium propionate
Definition
prevents growth of molds and Bacillus mesentericus on bread
Term
sodium nitrate/nitrite
Definition
-added to ham, bacon, sausage, hot dogs
-react with blood component of meat and preserve red color
-prevent growth of Clostridium botulinum
Term
Aldehydes
Definition
-among the most effective antimicrobial agents
-inactivate proteins by forming covalent cross links with functional groups on proteins(-NH2, -OH, -COOH, -SH)
-formaldehyde
-glutaraldehyde
Term
formaldehyde
Definition
can be used as gas or as a solution(37%) known as formalin
Term
glutaraldehyde
Definition
-more effective than formaldehyde
-used to disinfect hospital instruments
-2% soln Cidex
Term
Ethylene oxide
Definition
-very powerful sterilizing gas
-kills spores
-used in combo with CO2 and freon
-deep action-can penetrate paper, clothing, plastic, medical supplies
-works by alkylating proteins(cross linking nucleic acids and proteins)
Term
chlorine dioxide
Definition
-gas used primarily(>95%) for bleaching wood pulp
-disinfection of municipal drinking water
-used as pre oxident prior to chlorination of drinking water to destroy natural water impurities that react with free chlorine and produce carcinogens
-can also be used for disinfection(decontamination of anthrax and molds after Katrina)
Term
hydrogen peroxide
Definition
-commonly found in households and hospitals
-powerful oxidizing agent that disrupts cell membranes
-very good at disinfecting objects(packaging, contact lenses)
-not as good on open wounds because human cells contain catalase
Term
peracetic acid
Definition
-very effective against endospores and viruses
-not deactivated by catalase
-powerful oxidizing agent
-used to disinfect food processing and medical equipment(endoscopes)
Term
plasmas
Definition
-increasing use in health care facilities
-used for metal/plastic surgical instruments in arthroscopic and laparoscopic surgeries
-combo of a vacuum, electromagnetic field, and chemicals (peroxide)
-form highly reactive free radicals
Supporting users have an ad free experience!