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164 Cards in this Set

  • Front
  • Back
What are chemical influences on bacteria?
-antibiotics
-disinfectants
-heavy metals
What are physical influences on bacteria?
-heat, radiation, and filtration
What are cidal effects on bacterial growth?
-all bacteria are destroyed
-best solution in contriolling microorganisms
-need method for immunocompormised patients with weak uimmune systems
What are static efects on bacterial growth?
-stops bacterial growth
-allows patient's own immune system to catch up and handle the infection
What are the inhibitor effect on bacterial growth?
-slows down bacterial growth
-fission rate is slowed down and gives time for uimmuen system to fight back
What are chemical factors pertaining to amount needed on abcterial agents? Example?
-alcohol, clhorine, and phenol
-egenrally, the higher the concentration the chemcial, the more effeccvitve it tis'
-ethnaol/alcohol
-comes in 70%, 99& is better
-weater is required so not 100%
What are physical factors pertaining to amount needed for bacterial agents?
-heat, UV, x-ray, gamma ray, and radiation
-higher intensity=higher effectivness on bacteria
How is time a factor pertainign to control of bacterial agents?
15 minutes is usally required to autoclave/sterilize at 121.5 deg. C
-need 15 min with alcohol to kill a vegetative cell
-can;t kill endospores
How is temerpature a factor pertainign to control of bacterial agents? Examples?
higher temp= more effective
-for every 10 deg rise in temperature, rate of rection is doubled
-clostridium botulinum is cidal ater 113 deg C, not 100 deg
-phenol is cidal at 1%-5%
-amount of tie decrqass as concentration increases
How is load a factor prtaining to organism growth?
-number og organisms
-based on log scale
-cell death is exponetial. not instantaenous
-dcreasing cell load increases sensitivity of mincroorganisms
How is type of organism a factor pertainign to organism growth?
-G+vs G-
-G- is tougher to kill b/c of outer membrane
-spore vs vegetativee _
-only alcoohol can kill vgetaitv cells(121.5 at 125 min)
-virusees are mor rsistant to phenols and dryness
-need more heat for sprs
How does prvious history a factor pertaining to organism growth?
-yound is more sensisitve to chmical and physical agents, log growth
-mature is strogeest/ last sensitive (most resistant), log stationary
-old is weakest, has to deal with it toxins, log death phase
How is density a factor prtaining to nature of envrionement in bactrrial penetration?
-more dense=harder to penetrate
How are colloids a factor pertaining to nature of envrionment in bacterial inactivagtion?
-any particle too vig to form solutions but small nough to b suspended
-ex is blood,, feces, vomit
-chlorin is ineffectivr if itn attaches to colloid insteead of bacteria
How is pH a factor in penetration of bactria?
-halogens (Cl, I) are good in acid, bad in alkaline
-carbapenem= enzymes (dipeptidase) comes out in pee (beta lactam)
What is the mode of action of heat in general?
-method of choice in controllign microorganisms
-leaves no residue
What is incineration?
-very rapid oxidation of proteins, resulting in the orgaism burning at 700-1500 deg C
What is the mode of action of incineration?
-oxidation of proteins
-addition of oxygen=more intense oxidation
-removal of hydrogem=less intense
-occurs at 1000 deg c
-all organic material burned
-inorganic remains
-becomes sterile
-kills prions as well
-used for inoculating loops and biohazard waste
What are exampels of dry heat?
-incineration
-hot air oven
What is a hot air oven? What is the mode of action?
-160 deg C for 2 hours
-poor pentration
-used for metal or glass
-sterilizes dry matrial
-dehydration occurs
-protein oxidation occurs
-protein coagulation occursd
What are exampels pof moist heat for control of microorganisms?
-boiling
-free flowing steam
-steam under pressire
-high vacuum autoclave
-pasturization
-milk sterilzation
What is the mode of action for moist heat?
-protein coagulation
How is boilign used for control of microorganisms?
-disinfects (kills vegetative cells)
-scrubbing decreases load and washed off spores
-addign salt, sodium carbonate= increases boiling temperature
How is free flowing steam used for controlling of microorganisms?
-disinfects
-only advantage is less water log (less likly to fall apart)
-55 deg C= proteins denature
How is steam under pressure used for control of microorganisms?
-sterilize
uses a big tank to increase preesure to 15 lb/in2
-uses autoclave for 15 min at 121.5 deg c
-doesn't affect coagulation
-effective due to water
How is high vacuum autoclave used for controllign of microorganisms?
-30 lbs/ in2- makes steam reach temperautre of 135 deg C
-takes 3 min to sterilize
-prions removes after 1 hour
How is pasturization used for controllign of microorganisms? Methods?
-disinfects
-used for milk, beer, apple cider, and orange juice
-enough heat to remove non-spore forming pathogens
-Batch method- kills mycobacterium at 61.7 deg C for 30 min, now kills Rickettisa at 62.9 deg c at 30 min
flash method- high temper for short time (71.6 for 15 sec)
How is milk sterilzation used for controllign microorgansism?
-140 deg C for less than 1 second
-use for countires without refrigeration
How is scrubbign used for controlling of micro orgaisms? What methods are used?
-decreases load (never sterilizes)
-speeds up disinfecting
-soap (non germicidal)
-labile (germicidal soap)
-residual action (sticvks to skin and continues to work
-bacteria can't multiply
What are the different physical methods other than heat used to control microorganisms?
-scrubbing
-filtration
-dessication
-cold temperatures
-osmotic pressure
-sunlight
How is fuiltration used for controlling microorgaisms? Screen hole sizes?
-passes liquid or gas througha screen or something porous to remove microorganisms
-heat labile
-water passes through sand, gravel
-.45um- standard but some pass
-.2 um- sterilzes (mycoplasma and viruses pass)
.02um- clogs upa nd removes mostvirues, not prions and viroids
-.01 um prions can still slip through
-How is sendimentation used in controllign microorganisms?
-used for septic tanks
-ferric sulfagte sued to icnrease sendimentation
-treated after= filtration
-removes 90-95% of bacteria in water
-chlorine is aded to kill rest of pathogens
-bad for environment
How is dessication used in controllign microorganisms? examples?
-drying out, removes water necessary for enzymatic hydrolysis
-syphilis- min
-gonorrhea- hours
-staphylococcus clhoriforms- 2-3 months
-mycobacteria- 8 months
-spores- indefinatly
-aids virus- 6 hours outside of body, 1.5 days in cells
-hepatitis B- 7 days
How does dessication occur in foods? examples?
-if dried foods are kept dry, organisms can;t grow but not always cidal
-staph aureus incereals=can grow if liquid added
-salmonella in dried eggs- cna grow if left out to sit for 3 months
How does dessication occur in dried drugs? examples?
-many antibiotics come ina powdered form
-suscpetible to infection
-refirgerated and discarded after 2 weeks
-yeast infections and athletes foot can onyl cause problems in a moist environment
How are cold temepratures used in controlling microorganisms?
-freezing temperatures (less than 0 deg C) usually cidal to eukaryotic cells
-not cidal to bacteria
-stops grwth
-fridge is only inhibitory (slows down rate)
-freezer is static
How is osmotic presure used in controllign microorganisms?
-bacteria undergo plamolysis under hypertonic envrionment
-Brine has high salt conentrations, used for preservation of meats
-suagrs used to preserve fruit
-only halophiles and saccharophiles can live but not pathogenic
How is sunlight used in controlling microorganisms?
-mycobacterium TB cna live in 8 mothsn of desication but only a ferw hours under sunlight
-killed by phot-oxidation (removes H+)
How is radiation used for controling of microorganisms? Methods?
mainly affect DNA
-doesn;t affect prions
-ultraviolet light
-infrared waves and microwaves
-gamma rays
-cathode rays
-x-rays
How is ultraviolet light used for controllign microorganisms? Mode of action? Use?
-diinfects becasue it doens;t peentrate
-effective range is 253.7
-mode fo action is DNA forms pyrimidine dimers
-used for disinfecting air in laminar flow hoods
-possible water treatment in future
How do infrared waves and microwaves used in controlling microorganisms?
Infrared and Microwaves
Disinfects (at atmospheric pressure, only rises to 100c)
Mode of action:
Non-ionization
Wavelengths get absorbed and it gets given off as heat:
If it is dry it is protein oxidation
If it is wet it is protein coagulation
How are gamma rays, cathode rays, and x-rays all similar in controllign microorganisms? Mode of action?
Are all less than 1nm
Mode of action:
Uses ionizing energy (creates hyperactive ions)
Ions strike DNA and breaks bonds between bases
Results in mutation (may even cause death)
Cold Sterilizing = good (no need to heat up organisms)
No change in chemistry/breakdown in chemical compounds
How are gamma rays used for control of microorganisms?
penetrating except for lead
comes from radioactive cobalt
= radioactive isotope
Used for sterilizing thick things
Packaged meat (example: bacon)
Use to be preserved with nitrates
When cooked = carcinogenic (can cause cancer)
Gamma rays can now be used and do not deposit any radioactive materials in meat
Prions are not affected by gamma rays
How are cathode rays used ofr controlling microorganisms?
Electron beams of high intensity
Shoots at the sample
Non- penetrating
How are x-rays used for controllign micro-organisms?
Very effective
Very penetrating
Too dangerous for routine use
What is the mode fo action of denaturing proteins thruhg protein coagulation? What is cidal about it? What is broad spectrum? Narrow spectrum? Externally? Systematically?
= destroying 3D structures of proteins (i.e. enzymes)
= cidal (protein coagulant = protoplasmic poison)
* protoplasmic poison destroy anything with proteins, including humans)
= broad spectrum (works against G- and G+, and probably viruses, protozoa, and fungi as well)
* narrow spectrum works only against either G+ or G-
= can only be used externally because humans have protoplasm in their bodies as well
* externally = does not enter blood stream (like a pill)
* systematically = does enter blood stream (like IV)
How are strong alkalies and acids used for protein coagulation? Weaker forms?
Strong:
Bases include KOH, NaOH
Acids include HCl, H2SO4, HNO3
Aren’t used frequently because they are very damaging/caustic

Weaker:
NH4OH = strong base used for disinfecting floors, furniture, glass, etc.
Benzoic Acid = potassium benzoate
Needs salt to be soluble in water
Used in listerine, sodas
Potassium benzoate is used as an antifungal preservative
Propionic Acid = calcium propionate
Used in bread as an antifungal (black bread mold)
How are phenols used for protein coagulation?
= “carbolic acid”
= intermediate (both good and bad effects) as disinfectant
= effective in presence of organic matter (cleaning feces/vomit)
= are strongly microbiocidal against vegetative bacteria (even against mycobacterium - TB)
= analgesics (pain relievers)
= surgical disinfectant, acts against staph.
= originally used as surgical antiseptic
= used as preservative for vaccines
= very caustic
= not reliably sporocidal (kill spores)
= not effective against hepatitis B
= accumulates in environment
Whata re exampels of different phenols used for contorl of microorganisms?
-cresol
-orthophenylphenol
-bis phenols
-hexachlorophene
-triclosan
-chlorhexidane
-cresyl acetate
How is cresol used for control of microorganisms?
– alkylated phenols
Less water soluble than phenol because of methyl (-CH3) group
Emulsifying agent (like soap) is required to make it soluble
“oily” – stick to surfaces and leave a residue
Use to be used in Lysol
Creolin = good way to clean areas for pet or horses and make it smell good
How is orthophenylphenol used for controllign microorganisms?
Benzene ring attached to phenol at ortho
Used in Lysol now (because less toxic)
More water-soluble than cresol
What do bis phenols ahve?
-a lot of chlorine
How is hexachlorophene used for controllign microorganisms? What drug is it in?
2 phenols with 6 chlorine groups
Commonly used in soap, shampoos, and baby powders in the past
Has residual action (stays in human skin and gets deeper until neurotoxic)
1972: In france, it killed 40 babies
No longer available as OTC
In Rhisohex (3% hexachlorophene) as soap against staph. and strept. (G+)
Used in 0.1% concentrations as a preservative
How is triclosan used in controlling microorganisms? Example?
- a bis-phenol
3 Cl groups
Absorbed deep in the skin (soaps, shampoo, toothpaste – anti gingivitis)
Example: Pseudomonas aeruginoas (G-) = nonfermenter
Very resistant to antibiotic (triclosan)
Green in color, non-fermenting
Studied in labs but hard to get rid o
How does chlorohexidane used in cotnrolling microorganisms?
(NOT A PHENOL, no benzene)
NO – OH group but has Cl
Used in hospital as a replacement for Hexachlorophene as disinfectant
For washing hands
Has residual action but
Is not absorbed into skin cells
Usually used as 4% with 4% isopropyl
How is cresyl acetate used in controllign microorganisms?
Antiseptic for membranous surface: ears, nose, throat
Antiseptic and analgesic
Disinfects inanimate/antiseptic for animate
How are salts of heavy metals used for protein coagulation of microorganisms?
Low activity
Inactive in the presence of organic matter
Irritates human skin – delays healing
Crust forming (over stab or big cut)
Stops working after a while
Some are poisonous
How is mercuric bichloride (HgCl2) used in cotnrollign microorganisms?
Longest history of use as disinfectant
In 1-2% solutions
Not used anymore due to toxicity (mercury)
How is thimerosal (merthiolate used on controlling microorganisms?
Preservative for vaccines (tetanus)
Organic form of mercury
Widely used as preservative in vaccines and biologics
Preservative in some eye cosmetics
How is silver nitrate (Ag NO3) used in controlling microorganisms? What''s used instead now?
Still useful as disinfectant
Used in 1-2% solution (can indicate proteins)
Used to prevent ophthalmia neonatorum (infection in birth canals, eyes of new born babies) caused by:
Gonorrhea
Doesn’t work against Chlamydia trachometis
Erythromycin is now used in babies’ eyes (works against both gonorrhea and Chlamydia)
How is silver sulfadiazine used in contriollign microorganisms?
Sulfadiazine = type of antibiotic commonly called a sulfa drug
Use on dressings for burn patients
Very good for resistant organisms such as pseudomona ariginosa
Silver + antibiotic = good combo
How is zinc used in cotnrollign microorganisms?
Zinc oxide
Antifungal (for the athlete’s foot)
Zinc Chloride
Both are used in mouth washes, preservative
How are alcohols used for protein coagulation of microorganisms?
“Cold sterilants” – WRONG PERCEPTION
effectiveness increases by increasing molecular weight of alcohol
Methanol (CH3OH) = lowest weight/least effective
70% solution takes 10-15% to kill vegetative cells (never kills spores)
Whata re examples of alcohols used for controllign microorganisms?
Ethanol and isopropyl
-benzyl alcohol
How is ethanol and isopropyl used in controlling microorganisms?
Ethanol and Isopropyl
Used as rubbing alcohols and antiseptics
Completely ineffective against spores
Even vegetative cell need 15 minutes for alcohol to work
BUT it’s difficult to keep rubbing alcohol (which evaporates quickly) on the skin for 15 minutes
Ethanol Isopropyl
70% + +
35% - +
At 35% concentration, ethanol is no longer effective unlike isopropyl (isopropyl has a higher molecular weight)
How is benzyl alcohol used in contorllign microorganisms?
Has benzene ring
Insoluble in water
Used as preservative (in low concentrations) in external preparations (cannot be taken systemically)
What are oxidizing agents controllign microorganisms?
E-SH = enzymes with sulfhydryl group
Sulfhydryl group = active group on an enzyme

Oxidizing Agents removes hydrogen from sulfhydryl group to yield a mercuptide group
E-SH + E-SH -> E-S-S-E
Halogens = disinfectants
What are the advantages of halogens for conrollign microorganisms?
= Broad spectrum
= Bactericidal, viracidal, fungicidal, amoebacidal, slowly
What are disadvantages about using halogens fro controllign microorganisms?
= inactive in presence of organic matter (vomit, feces) and alkaline pH
= Irritants
Unstable solutions
What is a iodine tincture?
iodine and alcohol in a 1-2% solution
How are iodophores used in controllign microorganisms? what drug is it in?
Betadine = used as antiseptic before surgery
Betadine is used to for testing for Ophthalmia neonatorum (tests for STDs) because it has a lower cost
Contains poly vinyl alcohol (generally less irritating than iodine tincture)
Iodine and iodophors must be on a site for 2 minutes before the insertion of a catheter, according to the CDC
Whata re examples of Halogens used as oxidizing agents inc ontrollign microorganisms?
iodine tincture
iodoophors
-chlorine
-sodium hypochlorite
-halazone
How is chlorine used in controllign microorganisms?
= toxic gas used in water treatment
Added until there is a residual concentration of .5 to 1 ppm
How is sodium hypochlorite used in contorllign microroganisms?
5.25% NaOCl in bleach
= very irritating at full concentration
10% Bleach - .525% NaOCl, recommended for IV drugs, against AIDS
Always has to be made up fresh, no storage because the solution doesn’t last long after diluted
How is a halazone used in control,ling microorganisms? Example?
Tablet of organic chlorine that was frequently used by campers
Kills bacteria in water
Not effective against protozoa, especially those that have cysts (similar to capsules)
Example: giardia
Whata r eexampekls of oxidizing agents?
-halogens
-hydrogen perozide
How is hydrogen perozide used in controlling microorganisms?
Highly active
Sporocidal
Considered to be an ideal antiseptic disinfiectant because it breaks down into oxygen and water, so there are no toxic residues
2H2O2 -> O2 + 2H2O
Damages a lot of vegetative cells
Comes in a 3% solution
Our blood has catalase (which breaks down H2O2) releasing oxygen very quickly
In deep puncture wounds, organisms like tetanus and gas gangrene (anaerobes) are killed by the oxygen
At 10% it is a “cold sterilant” but too toxic to use on tissues at this concentration
Heat labile – broken down by heat. It is used to sterilize heat labile things which can’t be put into the autoclave, such as plastics
Whata re examples of alkylating agents?
-formaldehyde
-gluteraldehyde
-ethylene oxide
How is formaldehyde used in controllign microorganisms?
A gas
Formalin: 8% STERILANT, for surgical instrument
Cold sterilant because it has high sporocidal activity.
Becomes Carcinogen – has to be washed by sterile water before used
Used in embalming solutions
Used as a 1% solution to disinfect dialysis equipment (filter blood for patients whose kidneys do not work)
How is gluteraldehyde used in cotnrollign microorganisms?
= 2% cold sterilant (sporocidal)
Used in dentist’s offices, for respiratory therapy equipment, for cows teats in farm
how is ethylene oxide used in controllign microorganisms?
A gas, cold sterilant
Disinfect anything that’s powder (like Petri dishes)
OSHA regulated: can be explosive, carcinogenic
What are surfactants in disrupting lipoprotein to control microorganisms?
= surface acting chemicals that disrupt lipoprotein
= amphipathic
* polar head = soluble in water,
* non-polar tail (insoluble in water)
= insert themselves into the cell membrane
* At low concentration – disrupts the membrane
* At high concentration – dissolve the membrane (pokes holes in it)
= cidal but nonselective (could damage bacteria and humans)
What are the 3 types of dtergents used in cotnrollign microroganisms?
Cationic detergents (positive) = most active
Anionic detergents (negative) = mildly active
Nonionic detergents = no activity/effect
How are cationic detergents used in controlling microorganisms? Examples?
Quaternary ammonium compounds
4 alkyl groups around a central nitrogen (has 1 nonpolar tail)
Effective against G+ bacteria but have a low activity against G- bacteria.
DISINFECTANT
No activity against TB, Hepatitis B, spores
Has low toxicity (is used in food industry and hospitals)
Examples:
Benzalkorium chloride
Cetylpyridinium chloride:
Ophthalmic solutions
Cosmetics
Mouthwashes
How are anionic detergents used in controlling microorganisms? Examples?
Very mild disinfectants, so they only kill organisms that are sensitive
Pneumococcus
Gonoccoccous - Meningococcus
Syphilis
Gonorrhea
Examples:
Sodium lauryl sulfate: used in mouthwashes
Bile salts
We produce bile to emulsify lipids, protect our intestines
Taxo P identifies streptococcus pneumoniae (sensitive to bile)
What is an exmaple of nonionic deterggents in controlling microorganisms?
-soap
What are polymyxins and how are they used in controllign microorganisms?
Produced by bacteria to protect themselves
Isolated from Bacillus species
Ampipathic polypeptides (amino acids)
One part = cyclical, polar, water soluble end
Other part = non polar tail
There are various forms of polymyxins (A, B, C, D, E)
Poly B and E (colistin) = most frequently used
Disc diffusion techniques, such as Kirby Bauer, standardize antibiotics
The zone of inhibition (vary in sizes) = classified as R, S, or I
R = resistant
S = sensitive
I = intermediate
How is polymyxin b used in controllign microorganisms? What techniques can be used in determining whether it is broad or narrow spectrum?
Narrow spectrum (effective against G- bacteria, not G+)
Kirby Bauer, MIC, MBC and the E-test determine if an antibiotic is broad or narrow spectrum and if it is effective against the microbe you wish to treat.
What is the kirby bauer technique? Advantages? disadvantage? Breakpoints?
disc diffusion technique
Disks are placed with specific antibiotics on lawn of pure organism
Zone distance (in mm) is measured around disks
Different break points are observed for different antibiotics
Advantage: can test many different antibiotics at once
Disadvantage: break points don’t denote dosage
Breakpoints:
R = resistant, no zone
S = sensitive, large zone
This type of drug is most effective
I = intermediate, medium zone
This type of drug is used if the S causes an allergy in the patient)
What is tube dilution?
Dilution:
One antibiotic at a time is serially diluted and tested
MIC determines how much antibiotic is needed to stop growth
After a dilution of 4µg/ml: growth will stop (but organism is NOT killed)
MBC determines how much is needed to kill the bacteria
Kills the bacteria
Important in immunocompromised patients
Take MIC
Make agar plates with them
Look for growth to see which strength completely kills the bacteria
What is the e-test?
Gives the MIC without having to do the serial dilutions
The drug is in a strip of varying concentrations
The E-test isn’t quite as accurate as the serial dilutions (can’t determine the MBC)
Is fool-proof
What is the DOC?
drug of choice
The medical letter publishes this information for most infections
DOC – the most active drug against an infection as determined by Kirby-Bauer, MIC/MBC and E-tests (or) the least toxic drug to a patient
How is polymyxin B significant in contorllign microorganisms? what drug is it in?
Polymyxin B is too toxic to be the DOC for any infections.
= nephrotoxic (kidneys) and neurotoxic (nervous system)
Is still used on resistant bacteria
Acinetobacter =
Usually does not cause anything in healthy people
Can cause problems in the hospital where there are immunocompromised patients (nosocomial)
pneuomonia, meningitis
Is very resistant to antibiotics
So Polymyxin B is used even though some kidney damage may be done.
Patient = monitored very closely
Polymyxin B can be used externally without problems
OTIC infections - Otitis externa
Opthalmic infections
Skin infections
Found in triple antibiotic ointment
It is a good idea to vary treatment (keep bacteria from development resistance
How is polymyxin E used in controllign microorganisms?
Thayer martin selective agar (chocolate agar) used to grow out gonorrhea
Contains 3 antibiotics
Vancomycin (G+)
Colisin (G-)
Nystatin (Yeast) Inhibits, but does not kill
In theory, all of these should inhibit the growth of everything
Gonorrhea, however, still grows on this media because it is a G- cocci that is resistant to colisin
Used to treat otitis externa
What are polyene antibiotics? Mode of action?
Comes from the organism streptomyces
Large cyclic molecule with many double bonds
Mode of action: attacks the cell membrane (prevents the production of sterols in cell membrane)
Effective against ours and fungi’s cell membranes
Primarily fungistatic because of its ergosterol (steroid in fungi)
Inhibit sterols
Not effective against bacteria (don’t have steroids in cell membranes
Whata re exmaples of polyene antibiotics?
-nystatin
-amphotericin B
-Azoles
-triazoles
How is nystatin used in controlling microorganisms?
Not a DOC
Used for dermatophytic yeast infections – superficial yeast infection
The most common yeast is candida albicans
Causes oropharyngeal - thrush in aids paitents
Causes vulvovaginal candidiasis
Candida = usually not harmful
Can cause infection in extreme youth (could have picked up from mothers), pregnancy, antimicrobial therapy and nutritional disorders (such as diabetes)
= not given through IV for systemic infections because of its toxicity
Can be taken orally for years
How is amphotericin B used in controllign microorganisms?
DOC for Systemic Mycosis (fungal infection that attacks the inside of human body like organs)
Systemic Mycosis:
Systemic – happens inside our bodies in organ systems
Is caused by aspergillosis in immunocompromised patients.
Aspergillosis or aspergillus = dimorphic fungi (fungi that initially look like yeast in a patients blood)
At room temperature 25 C, looks like mold
At body temperature 37 C, looks like a yeast
Dimorphic fungi are dangerous
Is given through IV for serious infections
Whata re examples of azoles in controling microorganisms?
imidazole
-ketoconazole
How are imidazoles used in controllign microorgansimss?
Different Types: clotrimazol, miconazole, & ketonazole
Attacks/weakens the membranes by attacking the steroids
Clotrimazol and Miconazole– used for superficial yeasts
Used topically for mild dermatophytic infections like volvovaginitis caused by Candida Albicans.
Work within 3-7 days.
Also used for:
Ringworm (mold that affects skin of the body caused by Epidermophyton, Microsporum, and Trichophyton)
Athletes foot (caused by usually just Trichophyton and sometimes Epidermophyton)
Some can attack skin, skin and nails, or hair (the worst case)
How is clotrimazol and miconazole used in controllign microorganisms?
used for superficial yeasts
Used topically for mild dermatophytic infections like volvovaginitis caused by Candida Albicans.
Work within 3-7 days.
Also used for:
Ringworm (mold that affects skin of the body caused by Epidermophyton, Microsporum, and Trichophyton)
Athletes foot (caused by usually just Trichophyton and sometimes Epidermophyton)
Some can attack skin, skin and nails, or hair (the worst case)
How is ketoconazole used in controlling microorganisms?
can be used as topical or systematic
An alternate for systemic mycosis
It is not as soluble as the other drugs, so if a patient has aspergillosis in the nervous system, this drug cannot get through the BBB (blood brain barrier) to treat the patient like Amphotericin B can
What are the different types of triazoles? How do they work ion controllign microorganisms?
Different Types: Fluconazole (Diflucan) and Voriconazole
Are more water soluble
Fluconazole (Diflucan)
DOC for deep and superficial candiasis albican
One pill is good for a week (take a second pill if needed)

Voriconazole
Newer derivative of triazole
DOC for systemic mycoses, especially aspergillosis in AIDS patients because it is soluble and able to cross the BBB
How do antimetabolites work to suppress cell wall synthesis? What microroganisms does in usually work for?
Affects the murein synthesis
Narrow spectrum
More effective against G+ (which has more murein)
G+ bacteria have a higher internal pressure (20-30 atm) than G- (5 atm)
So a breakdown in their murein is much more drastic
Suppresses synthesis in cell wall in young, maturing cells
Not in mature because murein synthesis is complete
Works for:
Clostridium perfringens (gas gangrene)
Group A Streptococci : Streptococcus pyogenes
Neisseria meningitidis
Treponema pallidum: Syphilis (a sensitive G-)
What are penicillins? types?
Discovered from penicillium molds by Fleming while he was trying to grow staph on agar plate
Penicillins all have the same nucleus (with B-lactam ring) but differ in the side chain/R group that hangs off of the nucleus
This is especially important in the case of the presence of B-lactamase, which is an enzyme that some bacteria possess which allows them to break down the B-lactam ring
- natural, repository, and semi-synthetic penicillin
What types of natural penicillins exists?
-benzyl penicillin
-phenoxymethyl penicillin
How does benzyl penicillin (Pen G) work in controlling micrororganisms?
Narrow spectrum against G+
Used in IV applications because stomach acids break it down very quickly
Doesn’t stay in body very long (gets excreted after just 2 hours of treatment)
Was therefore modified to last longer in your body to yield Penicillin V
How do phenooxymethyl penicillins (Pen V) work in controlling microorganisms?
Same activity as Pen G but can be taken orally because it is resistant to break down by stomach acids
How do repository penicillin work in contriolling microorganisms? Types?
Time-released capsules (last longer than Pen G) because it’s less soluble
Are chemically modified Penicillin G
Injection (given intramuscular) stays in your system much longer
Procaine Penicillin (procaine mixed with Pen G)
Benzathine Penicillin (benzathine mixed with Pen G)
Used for syphilis
Used for sensitive organisms
Low level in blood, stays there for 18-24 hours
What types of semi-synthetic penicillins exist in controllign microorganisms?
-ampicillin
-amoxicillin
-carbencillin
How does Ampicillin work in contorllign microorganisms? DOC for?
= penicillin + amino group
Amino group makes it Broad spectrum
DOC for UTI (Urinary Tract Infections) by proteus mirabilis (a G- rod which is resistant to many antibiotics)
How is amoxicillin used in controlling microorganisms? DOC for?
= penicillin + hydroxyl group
Broad spectrum
Advantage is that instances of diarrhea are lower when taken orally
DOC for UTI, proteus mirabilis
How is carbenicillin used in controlling microorganisms?
= penicillin + carboxyl group
Used as an alternate (not Doc) for pseudomonas aeruginosa UTI infections
Pseudomonas aeruginosa
G- ROD
= resistant to most antibiotics
= difficult to treat because drug concentration is decreased down the urinary tract
Can cause UTIs and other infections
Could invade the bone, lungs, etc.
Adding salt to it makes it water soluble
How does ticarcillin used in controlling microorganisms?
= penicillin + sulfur ring
2-4 times more effective against pseudomonas than carbenicillin
DOC for the other infections that pseudomonas aeruginosa can cause
What problems exist with penicillin?
Some organisms produce B-lactamase, which inactivates penicillin
Are enzymes that can break down even semi-synthetic drugs
Whata r eexamples of beta-lactamase resistant p[enicillin?
-methicillin
-oxacillin
0cloxacillin
-augmentin
-zosyn
How does methicicllin work in cotnrolling microorganisms?
Modified side chain make it resistant to penicillinase
MSSA = Methicillin sensitive staph aureus
Staph developed resistance to pencillin through conjugation because penicillin was used so frequently on staph infections
MRSA = Methicillin Resistant staph aureus
Most strains of nesseria (gonorrhea) are resistant to Pencillin
Isolate bacteria, test penicillin
If penicillin is ineffective, use a B-lactamase resistant penicillin
How dos oxacillin work in controlling microorganisms?
parenteral (given by injection via IV)
How does cloxacillin work in contorllign microorganisms?
-taken orally for less severe infections
How does augmentin work in controlling microorganisms?
= amoxicillin + potassium clavulanate (a non-competitive inhibitor of penicillinase that allows for the amoxicillin to work)
How does zoxyn work in controlling microoroganisms? DOC for?
pipericillin + tazobactam (inhibits B-lactamase enzyme, preventing breaking down of pipercillin)
2-4 times more effective than Ticarcillin
Broad spectrum
DOC for pseudomonas aeroginosa
How do cephalosporins work in supressin cell wall synthesis?
Considered to be penicillin substitutes
= resistant to penicillinase
Sometimes the same plasmid that transfers penicillinase also transfers cephalosporinase
Allergies to cephalosporins are more rare
5% = allergic to pencillin
5-10% of those allergic to penicillin are also allergic to cephalosporin as well
Are a B-lactam antibiotic, but have 2 side chains instead of 1
Comes from a mold called cephalosporium
What generation sof cephalosporins exist to contorl microorganisms?
cephalothin
-cefotiam
-moxalactam
-cefapime
What generation of cephalosporin is cephalothin? how does it wokr? Drug?
first generation
Narrow spectrum
Cephalexin (keflex)
Used on G+ in staph and strept
What generation of cephalosporin is cefotiam in? How does it work?
second generation
Considered narrow spectrum but
Display more activity towards G- than 1st generation
Effective against proteus haemophilus, enterobacteria
What generation fo cephalosporin is moxalactam in? How dioes it work?
3rd generation
Ceftriaxone and cefotaxime = very soluble
Can pass through BBB
What generation of cephalosporin in cefepime? how does it work in controlling microroganisms?
-4th generation
Klebsiella pneumoniae (noscomial
What is a carbapenem? How does in control microorganisms? What examples of drugs exist? DOC?
Switch the sulfur and put a carbon in the ring
= more effective against G- infections resistant to 3rd and 4th generations (example: acinetobacter)
Primaxin = combination of imipenem and cilastatin
Imipenem = DOC for actinetobacter
Cilastatin
Prevents dehydropeptidase I from working on the renal tubule (kidneys)
Prevents impidem from being broken down in kidneys
What is bacitracin? how does in control microroganisms? What medicine is it in?
Comes from bacillus species (which also produces polymyxins)
Polypeptide = proteins
Narrow spectrum: effective against G+
Used in topical ointments
In combination: polymyxin for G-/bacitran for G-
Polymyxin B, bacitracin, neomycin in topical ointments
What is vancomycin? How does in control microorganisms?
DOC for MRSA but was overused and vancommucin resistant MRSA developed
Strongest/most powerful antibiotic
Is very toxic (needs to be closely monitored)
What is the mode of action for antimetabolites (aka competitive inhibitors)?
Competitive inhibitor (not cidal) = compound that is similar enough in structure to fit into the active site of an enzyme, but different enough that no products are formed (structural analogs)
Affects metabolism
Blocks synthesis
Usually static
Slows down/stops metabolism
Doesn’t always lead to death
If there were equal amounts of sulfa drug and PABA, reduce metabolism by 50%
Prokaryotes use PABA (Para amino benzoic acid) from dyhydrofolic acid to tetrahydrofolic acid and convert it through a metabolic pathway, as shown, to amino acids, purines and pyrimidines.
At each step of the pathway there are enzymes that can be disrupted with antimetabolites

PABA =1=>> Dihydropholic Acid =2=>> Tetrahydropholic Acid =3=>> Purines, Pyrimidines, Amino Acids
Whata re examples of antimetabolites?
-sulfanilomide
-sulfisoxazole
-bactrim (sulfmethoxazole and trimethoprim)
-sulfones
-isoniazid
-trimethoprim
-PAS (P-aminosalicyclic acid)
What is sulanilomide? how does in control microorganims?
Sulfa drug
Has benzene and amino group, making it a structural analogue
Works at the 1st step of the PABA pathway
One of the first sulfa drugs but not used anymore because of better drug choices
NOT cidal (static, inhibitory)
Sulfadiazine + silver used on dressings
Combo w/ silver prevents resistance; sulfa alone will cause bacterial resistance quickly
What is sulfisoxazole? How does it work against microrogansims? Difference b/t uncomplicated and complicated use?
Has better solubility so it is used instead of sulfanilamide

Uncomplicated = commonly E-coli from feces which get into urinary tract
Complicated = antibiotics caused normal flora to wipe-out and more resistant
organisms to come in
= Instrumentation: catheter may be contaminated
= Blockage: no mucus plugs, bathe regularly
Used for actute, uncomplicated UTI (e. Coli)
Complicated = disease resulted from antibiotic therapy, instrumentation (like catheter), blockage
In 3% of the population, a strep pyogenes infection initiates an allergic reaction in which the strep causes rheumatic fever, which can cause heart problems later in life. To combat this now, young children known to be susceptible to rheumatic fever are given sulfisoxazole if they are allergic to penicllins to avoid getting strep pyogenes infections
what is bactrim? How does in control microorganisms?
Sulfamethoxazole + trimethoprim = bactrim
Trimethoprim isn’t a sulfa drug, but is an anti-metabolite
Works at the first and second step of the PABA pathway
Used for pneumonia caused by pneumocytis carinii (PCP), now called pneumocytis jeroveci
causes pneumonia in AIDS patients
end-stage (type of fungus)
what usually kills AIDS patients
Can treat E. Coli
Works at 2 points of the pathway, so it kills better.
What is synergistic action?
the combination of the 2 is more effective than either drug alone.
Also, because it is more effective, lower, less toxic doses can be used and there is less a chance of resistant strains developing.
What is a sulfones? What is it a DOC for?
Dapsone – DOC for leprosy (which is caused by mycobacterium leprae
What is isoniazid? how does in control microorganims? DOC for?
Antimetabolite
Aka INH – Isonicotinic hydrazide
Structurally similar to B Vitamins (specifically pyridoxine and nicotinamides)
Prevents incorporation of mycolic acid into the cell wall
DOC for TB (caused by mycobacterium tuberculosis
What is trimethoprim? how does in control, microroganisms?
Used in combination with sulfamethoxazole
Treats acute uncomplicated UTI’s and pneumocytis jeroveci
What is PAS (p-aminosalicyclic acid)? how does it contorl microorganisms?
Used for Tb, especially MDR TB (multiply drug resistance TB)
What is significant about the chemical method of inhibiting protein synthesis and nucleic acid synthesis?
These drugs affect human cells as well (have a mitochondria, which use to be bacteria)
Affect ribosomes (translation)
Oto(ear) or nephro (kidneys) toxic
What are the various agents for inhibiting protein synthesis?
-aminoglycosides
-tetracyclines
-nitrobenzene derivatives
-macrolides
-synercids
-linezoids
What aminoglycosides exists in inhibiting protein syntheisis?
-streptomycin
-neomycin
-spentinomycin
-gentamycin
-caprenycin, kanamycin,a nd amikacin
How is streptomycin used in inhibiting protein synthesis?
One of the first drugs used against TB
Used for plague (caused by Yersinia pestis)
Used to treat MDR TB
how is neonycin used in inhibitng protein synthesis?
Is used topically as an antibiotic ointment
Triple antibiotics in topical ointment: neomycin, polymyxin B, and bacitracin
How is spentinomycin sued in preventing protein syntheisis?
Used to treat gonorrhea (especially for pregnant women who are allergic to pencillin and cephalosporins)
Hoew si caprenycin, kanamycin, and amikacin used i inhibitng protein synthesis?
-used for XDR and MDR TB
-injectable
What isa tetracycline? How is it used in inhibiting protein synthesis?
Doxycycline, tetracycline
Used as a penicillin substitute
Used for G+ infections
Used against:
Rickettsial (rocky mountain spotted fever)
Chlymydia infections (chlymydia trachomatis causes STD in urinary tract)
Mycoplasm pneumoniae – caused walking pneumonia, in which there aren’t very severe symptoms
Lyme disease is caused by borellia, which is spread by ticks
What nitrobenzene dereivative chloranophenical? How does it inhibit protein synthesis?
Causes aplastic anemia (prevents bone marrow from producing RBC and WBC)
Use when no other treatment is effective
Meningitis (haemophilus influenzae)
Deadly to children under 2
Typhoid Fever (salmonella typhae)
Can be deadly, and resistant to many antibiotics
VRE (vancomycin resistant entercocci)
Very resistant cocci that causes infection
Infects the intestinal tract
Can go into the blood stream to the heart
Whata re examples of macrolides in inhibiting protein synthesis?
-azithromycin
-erythromycin
What is azithromycin? what is ti DOC for in inhibitng protein synthesis?
(zithromax, Z-pack)
DOC for:
Chlymydia trachomatis UTI
Mycoplasma pneuomoniae
Legionella pneumophila which causes Legionnaire’s disease (type of pneumoniae that can be deadly, caught on cruise ships)
What is erythromycin a DOC for in inhibiting protein synthesis?
DOC for:
Mycoplasma pneumonia
Diphtheria (caused by corynebacterium)
Pertussis (whooping cough, caused by bordetella pertussis)
Used against Ophthalmia neonatorum (Chlamydia trachomatis) instead of silver nitrate 1-2%
Used against Nesseria Gonorrhea
What is a synercid? how does it work in inhibitng protein synthesis?
Quinupristin and dalfopristin
Used for VRE (vancomycin resistant enterococci)
Not used frequently against anything else
What is a linezoid? What is used for in inhibiting protein synthesis?
(zyvox)
Replaced synercid
DOC for VRE
Effective against more types of entercocci (broad spectrum)
= alternate for MRSA (Vancomycin = DOC)
Blocks methionine-tRNA during translation
Methione t-RNA starts every protein
Binds with mRNA
The RNA bind with small ribosomal subunit (ternary complex)
What is inhibition of nucleic acids? How?
DNA and RNA are made by nucleotides
A few ways to inihibit nucleic acid synthesis:
Structural analogue = antimetoblites
Inhibit metabolism with prine or pyrimdine analogues
Work against DNA and RNA
Effective against eukaryotes (humans, helminthes, fungal infection, protozoa) bacteria, and viruses (does not affect as much as the others)
Inhibit microtubules: cytoskeleton (during mitosis/meiosis)
Present in all eukaryotes
Prokaryotes don’t have a complex cytoskeleton
Absent in viruses
Affect enzymes (DNA and RNA polymerase, DNA gyrase)
Whata re agents that itnerfere with RNA synthesis? How do they work?
Rifampin
DOC for TB by blocking RNA polymerase
Ethambutol
Inhibits the incorporation of mycolic acid into TB cell wall
Whata re agents that interfere with DNA synthesis?
-acyclovir
-AZT (azidothymidine)
-Griseofulvin
-chloroquine, primaquine, and quinine
-quinolonesw (flouroquinolones)
-metronidizole (Flagyl)
-Mebendazole
How does acyclovir work in interfereing with DNA synthesis?
= structural analogue (affects purines, guanine and adenine)
Used against herpes virus
How does AZT (azidothymadine) work in interfereing with DNA synthesis?
structural analogue for thymine (a pyrimidine
How does Griseofulvin work in interferign with DNA synthesis?
Blocks microtubules (and therefore cell division)
Antifungal
DOC for severe cases of athlete’s foot (trichophytonm, get into skin and hair as well)
Toxic
How is chkiriquine, primaquine, and quinine used in interfering ewith DNA synthesis?
Quinine = used for 100s of years for malaria
= extracted from bark of cinchona tree
= very bitter tasting
bacteria developed resistance against it
Primaquine and chloroquine = developed
Mode of action for all:
Bind DNA (keep from separating) and prevents replication
Malaria = protozoa in red blood cells
Digests hemoglobin
Engulfs food
If phagocytize quinine, the pH is basic (alkaline)
It inhibits heme polymerase enzyme
Protozoa get build up of heme and dies
How does quinolones work in interfering in DNA synthesis? DOC for?
Interferes with DNA gyrase (enzymes allow coiling and uncoiling of DNA)
Ciprofloxacin
DOC for gonorrhea, anthrax, pseudomonas aeruginosa (UTI)
Norfloxacin
Used for MDR TB, INH ripampin, aeruginosa
Norfloxacin is an oral broad-spectrum fluoroquinolone antibacterial agent used in the treatment of urinary tract infections.
How does metronidizole work in interfering with DNA synthesis?
Anaerobic conditions
Used for protozoa infection
Example: amoebic dysentery and trichomonas vaginalis (both of which grow anaerobicaly)
DOC for antibiotic associated colitis
Antibiotic associate = caused by taking antibiotics
Colitis = inflammation of colon (part of large intestine)
The antibiotics kill the microbial flora in the digestive system, making room for opportunistic microbes such as clostridium difficile to grow in the intestinal tract because everything else dies. Diarrhea results.
What is mebendazole used for in itnerfering with DNA synthesis?
Anti-helminthes (Used for round worms/flat worms)
Interferes with microtubules/cytoskeleton