Microbiology: Controls Flashcards
What are the environmental zoonotic controls?
- Reservoir
- Vector
- Infected animals
How are zoonotic diseases in a reservoir controlled?
draining swampy areas
What zoonotic diseases live in reservoirs?
- giardia
- flukes
How are zoonotic diseases in a vector controlled?
eliminate or reduce exposure to vectors
What are the zoonotic vectors?
- mosquitos with West Nile Virus
- ticks
- fleas
How are zoonotic diseases controlled in infected animals?
- isolation of infected or clinically ill animals
- quarantine
- animal control laws to prevent roaming, mating, and interaction of these animals
What is sterilization?
kills all organisms including all spores and viruses
What is disinfection?
- kills vegetative organisms, not spores
- kill harmful organisms
How is pasteurization used to control zoonotic diseases?
- use of heat to keep bacterial growth under control
- reduce harmful bacterial or organisms to “acceptable levels”
- extend shelf life of food
What does bacteriostatic mean?
- prevents organisms from growing or reproducing
- doesn’t kill bacteria
- keeps bacteria “in place”
What is an antiseptic?
chemical for destroying harmful microbes for living tissue
Example of an antiseptic
Listerine
What is sanitation?
- lower microbe count to “safe public health levels”
- used for glassware, utensils
What are the types of radiation used to control zoonotic diseases?
- Ionizing
2. Non-Ionizing
What is ionizing radiation? (Examples)
- high energy light
- x-rays
- gamma rays
How effective is ionizing radiation?
- very effective, high penetration
- don’t have to heat
- cheaper
How does ionizing radiation work?
- knocks electrons off of atoms, rearranging them
- destroy, sterilization
What is ionizing radiation used for?
- sterilize medical devices
- heats sensitive substances like spices
- will sterilize food but not well accepted
What is non-ionizing radiation?
usually referring to UV light
How does non-ionizing radiation work?
does not penetrate well
What is non-ionizing radiation used for?
- good for surfaces
- water
What is the down side of non-ionizing radiation?
causes DNA damage
What is filtration used for?
useful for liquids and gases
What is membrane filtration?
many available down to pore size that will trap viruses
What needs to be used with a membrane filter and why?
- pre-filter
- can clog easily
What is a HEPA filter used for?
- air in clean rooms
- hospitals
- labs
What are the different types of chemicals used to control zoonotic diseases?
- Alcohols
- Heavy Metals
- Phenolics
- Iodine
- Chlorine
- Quaternary
- Oxidizing Agents
What does alcohol work as?
disinfectant
How does alcohol work against bacteria?
dehydrates proteins, dissolves lipids
How effective is alcohol against bacteria?
- mildly effective
- mostly washes organisms away mechanically
- low toxicity, cheap
How is alcohol used?
used as 50-80% solution
How does water work with alcohol?
water helps prevent evaporation and assists in penetration into tissues
Besides being used as a disinfectant, how else in alcohol used?
- preserve cosmetics
- treat skin before venipuncture or injection
What are heavy metals used as?
disinfectant
What are the commonly used heavy metals?
- Hg (mercury)
- Ag (silver)
- Cu (copper)
How effective is are heavy metals as a disinfectant?
mildly effective
What are the down sides to using heavy metals?
- higher toxicity
- not very popular anymore
- mostly used for waste disposed
How do heavy metals work?
- binds proteins together
- cellular metabolism is disrupted
What is Silver Nitrate used as?
- as an antiseptic
- as a disinfectant
What was Silver nitrate used for in the past?
after babies were born, AgNO3 was put into their eyes to prevent Neisseria gonorrhoeae being passed from mother to child
What are phenolics used as?
disinfectant
What was the first disinfectant used?
phenols
What are phenols compared to?
standard for comparing all disinfectants
How effective are phenols in the presence of organic matter?
doesn’t work as well with organic matter
Why are phenols not used as an antiseptic?
- expensive
- odiferous
- caustic to skin
What old cleaning solution used phenol?
old formula Lysol
What are the Phenol derivatives?
- Crestols
- Hexylresorcinol
- Bisphenols
- Triclosan
How effective are crestols with germs?
greater germicidal activity with lower toxicity
What else are crestols used for?
preserving wood
Where are hexylresorcinols used?
- mouthwash
- topical antiseptics
- throat lozenges (sucrets)
How does hexylresorcinol work against zoonotic organisms?
- reduces surface tension
- loosens bacteria from tissues and allows greater penetration
What are bisphenols?
- combination of 2 phenol molecules
Examples of bisphenols?
- Orthopheylphenol
- Hexachlorophene
- Chlorhexidine
Example of an orthopheylphenol
Lysol
Example of a Hexachlorophene
dial soap
What is chlorhexidine used for?
- surgical scrub
- hand wash
- skin wound cleanser
- antiplaque and anti-gingivitis
What is another name for chlorhexidine?
Nolvasan
What can happen if chlorhexadine sits out for a while?
bacteria may actually grow in it
What kind of coverage does Triclosan have?
broad spectrum
blocks the synthesis of lipids
What are the commercial names for Triclosan?
- irgansan
- Ster-zac
What is triclosan effective against?
- pathogenic bacteria
- partially effective against fungi and viruses
What is triclosan commonly added to?
- antibacterial soap
- lotions
- mouthwashes
- kitchen sponges
- tooth paste
- toys
- food
- utensils
- cutting boards
- underwear
What is the problem with putting Triclosan in everything?
bacteria can develop a resistance to it
How strong is Triclosan?
mild and non-toxic
How effective is iodine and is it toxic?
- effective
- low toxicity
- stains
What is a tincture of iodine and what is it used for?
- antiseptic for wounds
- iodine and ethyl alcohol
- can be used in drinking water
- used in restaurants for eating utensils
What are iodophors?
- iodine detergent complexes
- long term release of iodine
What does the detergent part of iodophors do?
loosens organisms from surfaces and then iodine can kill them
What are the commercial names for iodophors?
- Ioprep (surgical scrub)
- Iosan
- Betadine
What is it called when iodine is combined with non-detergent carrier molecules?
povidine
What does Povidine do?
stabilizes iodine and releases it slowly
What can still grow in Povidine?
pseudomonas
What can chlorine bleach be in the form of?
liquid or gas
What is bleach widely used in?
water supplies
What is bleach corrosive to?
metals
What is the inorganic form of chlorine (bleach) and what is it used for?
- NaOCl
- used as a bleaching agent for textiles
- used in dilute formulas for drinking water, swimming pools, and factory equipment
What is organic chlorine (bleach)?
- Chloramine T.
- releases chlorine slowly
- more stable than inorganic
What is organic chlorine (bleach) used for?
general wound antiseptic and root canal therapy
How effective is chlorine as a disinfectant/antiseptic?
- effective
- broad spectrum including some viruses, fungi, and protozoa
- not a sporicide (spores)
What are Quarternarys?
ammonium chloride
- low toxicity
- moderately expensive
Where are quaternarys good to use for?
- food
- processing plants
- hospitals
How do quaternarys compare to chlorine?
less corrosive
Examples of Quarternarys
- Parvosol
- Roccal-D
- 409 (don’t mix with soap)
What do quaternarys work against?
- broad spectrum
- bacteriostatic
- Gram (+)
What are the 3 oxidizing agents?
- Peroxide
- Ethylene Oxide
- Glutaraldehyde
What is peroxide used for?
- food processing plants
- skin disinfection
How do the bubbles of peroxide work?
they help with mechanical removal of organisms
Toxicity of Peroxide
low
What happens when there are organisms with enzymes to break down peroxide?
have to use a higher concentration of peroxide
What is peroxide being used for experimentally?
- milk
- soft contact lens
- utensils
What is ethylene oxide?
an explosive gas used in a chamber to sterilize medical instruments, bedding, etc.
Why must fabrics be aired out after being sterilized by ethylene oxide?
- it is very toxic
- could cause “cold burns”
What is ethylene oxide really good for?
plastics
- petri dishes
- plastic syringes
What is glutaraldehyde used for?
- good for surface sterilization of heat sensitive objects
- delicate instruments such as fiber optics
What does glutaraldehyde work against?
spores
What is glutaraldehyde used for?
- good for surface sterilization of heat sensitive objects
- delicate instruments such as fiber optics
What are the down sides of using glutaraldehyde?
- very toxic
- carcinogen (causes cancer)
What are the structural barriers for body defenses?
- skin
2. mucous membrane
What are non-specific defenses?
act on all invading organisms and toxins in some manner
What environment does skin have?
- dry
- salty
- slightly acidic
- keratinized
How does skin help protect the body from pathogens?
- unbroken skin is very hard to penetrate
- skin cells grow rapidly and sheds off layers of dead skin constantly
What happens when the skin sheds?
- sheds organisms
- secretes oils containing lysozymes
What are the common skin inhabitants?
- staphylococcus
- Bacillus
- Corynebacteria
Are the common skin inhabitants beneficial, opportunistic, or pathogenic?
opportunistic
What are the fungi that can infect hair, nails, and skin?
- ringworm
- foot rot
(may become systemic)
Where are the mucous membranes found?
- respiratory tract
- conjunctiva (eye)
- genitourinary tract
- GI tract (mouth and intestines and stomach)
How does Luceferin work?
Measures ATP
Where is luceferin used?
Food processing centers
Operating rooms
What is glutaraldehyde used for?
- good for surface sterilization of heat sensitive objects
- delicate instruments such as fiber optics
What are the down sides of using glutaraldehyde?
- very toxic
- carcinogen (causes cancer)
What are mucous membranes constantly doing?
- secreting mucous
- flushing away things
What does mucus contain?
- lysozymes
- antibodies
- acids
The respiratory system also has ______ cells to move inhaled material up and out.
ciliated
Lung cells have ________ cells to attack anything that gets past cilia.
phagocytic
What triggers the coughing reflex?
build up of material in the lungs
Where in the intestines are a normal flora of bacteria found?
lower
What kind of relationship do GI bacteria have with the host?
symbiotic
What do GI flora do to pathogens?
- keeps them in check
- microbial antagonism
The _______ comes into contact with many organisms. (part of body)
mouth
What enzymes are in saliva?
lysozymes
Why is saliva important for controlling microorganisms in the mouth?
- constantly flushing
- organisms that can cause tooth decay and gingivitis
What pH does saliva have?
low
Many viruses invade the body via _______ ?
mucous membranes
Where are the mucous membranes that viruses are most likely to enter the body?
- eyes
- respiratory system
- mouth
What are the 2 non-specific body defenses?
- structural barriers
2. chemical compounds
What are the chemical compounds that the body uses to defend itself?
- acids
- lysozyme
- digestive enzymes
- complement system
- interferon
What are the acids used in body defense?
- fatty acids
- sweat acids
- hydrochloric acid
What do fatty acids do?
directly toxic or upsets cell membranes
Acids in the sweat do what?
- help maintain a low pH
- pH 4-6
(most bacteria don’t like this pH
Where is hydrochloric acid found?
in the stomach
What does hydrochloric acid do?
- digests food
- kills most bacteria
What organism can survive in HCl?
Helibactor pylori
What does Helibactor pylori cause?
stomach ulcers in humans
What do lysozymes do?
helps digest Gram (+) cells walls
Where are lysozymes found?
- found in mucus, tears, saliva
- also inside phagocytes
What are the digestive enzymes?
- Amylase
- Lipase
- Trypsin
What do the digestive enzymes do?
- help digest starch, fat, and protein
- upset cell membranes and cell walls of microbes
What do bile acids do?
- help remove organisms
What makes up the complement system?
a set of 20 proteins in circulation
What doe the complement system do?
- assists the immune system
- attracts phagocytes, lymphocytes
- helps digest other cells
What does interferon do?
- virally infected cells secrete
- triggers surrounding healthy cells to produce antiviral proteins
- limits viral spread
What are the cell-mediated defenses?
leukocytes
What do leukocytes do?
specialized cells capable of acting in a specific manner towards individual pathogens
What are the 2 types of leukocytes?
- granulocyte
2. agranulocyte
What are the granulocytes?
- Basophils
- Neutrophils
- Eosinophils
What are the agranulocytes?
- monocytes
2. lymphocytes
What do neutrophils do?
- phagocytic
- first line of defense against bacteria
What do eosinophils do?
phagocytic
What do basophils do?
secretes useful substances
What do monocytes do?
- macrophages
- phagocytic
- eats chunky debris
What do lymphocytes do?
- natural killer cells
- produce antibodies (immunity)
- recirculates in blood stream
- recognize foreign cells or infected cells and neutralize or kill the cell
What is immunity?
resistance to disease causing organisms or toxins
What is an antigen?
- typically foreign
- stimulates antibody production
What is an antibody?
soluble protein made by B-lymphs that selectively bind to antigens
What does an antibody do?
attach to antigen binding sites
What is an antibody titer?
measures amounts and classes of antibodies
What are antibody titers used for?
can determine exposure to or measure protective antibody levels
What is an allergic response?
overstimulation of immune system by allergen
When does an allergic response happen?
after re-exposure to allergen
What are monoclonal antibodies?
- manufactured by cell cultures
- make one type of antibody in large amounts
What is used to make cell cultures for monoclonal antibodies?
- mouse spleen cells
What is the problem with using cell cultures?
hard to keep them alive
What are the different types of immunity?
- Natural Active
- Artificial Active
- Natural Passive
- Artificial Passive
What is natural active immunity?
- develops after recovery from a naturally acquired infectious disease
Microbial agents stimulate immune responses that remain _______ for years.
active
Body retains a ______ of the antigen so that any ________ to that antigen will result in a rapid response.
- memory
2. re-exposure
What is artificial active immunity?
antigens are introduced to a body by artificial means
- vaccination
The body must act to form antibodies by doing what?
- intentionally making a memory to the antigen without forcing the body to experience the disease
(protection from the disease)
What is natural passive immunity?
- newborns receive antibodies from mom during gestation
- some mammals get antibodies in colostrum
How do birds and reptiles pass antibodies to offspring?
though the egg yolk
How long do antibodies from colostrum last on humans and in animals?
- humans: 3-6 months
- animals: 6-12 weeks
What is artificial passive immunity?
preformed antibodies via injection
How long do preformed antibodies that are injected last?
several weeks
What is antiserum?
develop high levels of antibodies in horse and cattle and then collect the serum
Monoclonal antibodies or ______ antiserum is now available.
human
Artificial Passive Immunity can be used as ______ for high risk population.
prophylaxis
Artificial passive immunity injections are used post-exposure to what?
- diphtheria
- tetanus
- botulism
- rabies
How are killed vaccines made?
- pathogen exposed to heat or chemicals
- antigens are not altered but microbe cannot multiply
What is another name for killed vaccines?
Inactivated vaccines
To obtain maximum stimulation of antibodies from a killed vaccine, what should be done?
Give in a series of injections
Immunity from killed vaccines does not last as long as naturally acquired pathogens.
What must be given to increase effectiveness of the killed vaccine?
Booster shot
Example of a killed vaccine
Rabies vaccine
What are attenuated or weekend vaccines?
- Low virulence microbes that will multiply in tissue
- weakened or reduced in force
What does a single dose of an attenuated vaccine do?
Single-dose stimulates a high antibody level that lasts a prolonged time
Sometimes able to give a vaccine through ___________ route of infection.
Natural
What is an example of a vaccine given through natural routes of infection
Polio - orally
What are the disadvantages of attenuated vaccines?
- disease may result from vaccine itself
- immune compromised or pregnant animals should not receive these vaccines
What are subunit or recombinant vaccines?
- use purified fractions of the microbe
- helps reduce side effects
Genetic engineering is helping to create new vaccines by purifying only the __________ required to stimulate protective immunity.
Antigen
Example of a subunit or recombinant vaccine
Hepatitis B
How is the hepatitis B subunit vaccine made?
Borrow surface antigen made by yeast cells through a recombinant DNA technology
What are toxoid vaccines?
Contain inactivated toxins or toxoids rather than the killed cells
What are the diseases that are caused by exotoxins?
Diphtheria
Tetanus
What are antibodies created against exotoxins called?
Anti-toxins
What are DNA vaccines?
Inject bare DNA from infectious agent and the host will make some of it’s proteins
What happens when the host is injected with a DNA vaccine?
Develop antibodies in response and develop immunity
What does a DNA vaccine mimic?
Viral infection
