ch. 13 + 14 - AGENTS AND ABX ONLY Flashcards
(31 cards)
what ABX class/drugs inhibit cell wall synthesis?
- natural penicillins: PCN V and PCN G.
narrow. only gm (+) - penicillinase-resistant: Oxacillin.
semi-synthetic. narrow, only gm (+). - aminopenicillins: Ampicillin.
broad spectrum. not resistant to penicillinase. - penicillin + B-lactamase inhibitor: Augmentin.
Amoxicillin + Clavulanic acid.
broad spectrum AND resistant to penicillinase. - carbapens: Primaxin.
Impenem + Cillastatin.
the most broad spectrum; a last line of defense.
it prevents ABX from being degraded in the kidneys. - monobactams: Aztreonam.
narrow. only gm (-)
fully synthetic. - cephalosporins: 1-5 gens.
1st gen - narrow. only gm (+)
2nd - 5th gen - broad. - polypeptides: Bacitracin and Vancomycin.
narrow. gm (+).
non-B-lactam.
- Bacitracin is for tropical use.
- Vancomycin is the last line of defense used to treat resistant S. aureus INFXS (MRSA). - anti-mycolic acid: isoniazid and ethambutol.
- isoniazid: inhibits the SYNTHESIS of mycolic acid.
- ethambutal: inhibits the INCORPORATION of mycolic acid into the cell wall.
what drugs inhibit protein synthesis?
!! the only bacteriostatic category.
- Nitrofurantoin: fully synthetic and broad spectrum.
PRODRUG: converted/activated by the enzyme nitrate reductase from the microbe itself.
attacks the ribosomal proteins. - Chloramphenicol: broad spectrum and fully synthetic.
inhibits the polypeptide formation between amino acids, causing mRNA misreading.
attacks the 50S subunit of the 70S ribosome.
- TREATS: rickettsial, like lime disease.
- SIDE EFFECT: suppresses bone marrow, which causes hemoglobin levels to drop. - Aminoglycosides: streptomycin, neomycin, gentamycin.
broad spectrum.
attack the 30S subunit of the 70S ribosome.
attacks the amino acid sugars which are attached by glycoside bonds.
- SIDE EFFECT: can cause auditory damage like tinnitus. - Tetracycline: broad spectrum and an antibiotic.
interferes with tRNA attachment, which is what binds amino acids to mRNA.
- TREATS: rickettsial and chlamydia; penetrates tissue. - macrolides: Erythromycin.
narrow. only gm (+).
PCN G alternative.
blocks the ribosomal tunnel, therefore mRNA cannot be translated into a protein.
what drugs inhibit nucleic acid replication?
- Rifamycin: RIfampin.
mycobacteria!
- TREATS: leprasy and tubercolosis.
- side effect: red urine, red tears. - quinolones/fluroquinolones: Ciproflaxin (Cipro).
syntheitc. broad spectrum.
inhibits the enzyme DNA gyrase.
- TREATS: UTIS.
- SIDE EFFECT: tendon rupture.
what drugs cause injury to the plasma membrane?
- lipopeptides: Polymyxin B.
narrow. only gm (-).
disrupts the synthesis of fatty acids.
topical formulation.
what drugs cause competitive inhibition of essential metabolites?
- anti-metabolites: Sulfanamides.
drug synergism: sulfanilamide-trimethoprim.
broad spectrum.
- sulfanilamide: on 1st enzyme: competes with the enzyme PABA to prevent making dihydrofolic acid.
- trimethoprim: 2nd enzyme. prevents the formation of tetrahydrolic acid
OVERALL: blocks the microbe from creating folic acid so that proteins and nucleic acids like DNA are not made.
what chemical agents disrupt the plasma membrane?
- phenol: carbolic acid.
used by Joseph Lister as an anti-septic.
the standard for comparison. - phenolics:
i. Cresol: most common. made from coal tar.
ii. O-phenylphenol: a type of cresol found in the disinfectant Lysol. - biphenols: not common. microbes are resistant.
found in hand soaps and lotions; disinfectants.
i. hexachlorophene.
ii. tricloxan: found in mouthwashes. - biguanides: chlorhexidine.
anti-septic. founding surgical hand scrubs.
non-sporical. - essential oils: peppermint, pine, orange.
treats mostly gm (+).
for surfaces and skin. - surface active agents: soaps.
degerm and for emusifcication.
what agents impair protein synthesis and alter the plasma membrane?
- halogens: active against endospores and microbes!
i. iodine:
- tincture.
- iodophors: longer acting.
AND
ii. chlorine:
- bleach.
- chloramine: chlorine + ammonia.
disinfectant used at restaurants.
- chlorine: shuts down the ETC. water sanitation at pools. - alcohol:
i. ethanol: 70% concentration used for biocide.
AND
ii. isopropanol: has no effect on endospores and non-enveloped viruses.
antiseptic + disinfectant such as in rubbing alcohol.
what agents cause protein denaturation?
- heavy metals: use oligodynamic action, which is the ability of small amounts of heavy metals to kill microbes.
i. silver nitrate.
AND
ii. silver sulfadiazine. - aldehydes:
i. formaldehyde: not used. the 1st conservative used in cadavers.
AND
ii. glutaraldehyde: liquid chemical sterilizing agent.
NOT used in humans! used for endospores and mycobacteria.
used for embalming.
antifungal drugs include?
antifungals target ergosterol to injure the plasma membrane.
- Polyenes
i. Nyastatin: treats thrush or oral candida. - Azoles
i. imidazoles like Clotramazole and Micoazole.
treats tropical infections of the skin.
which ABX only treat gm (+) bacteria?
- PCV V and PCN G
- Oxacillin.
- polypeptides: Bacitracin and Vancomycin (MRSA).
- Macrolides: Erythromycin (mRNA. blocks tunnel)
which ABX only treat gm (-) bacteria?
- Monobactam: Aztreonam
- Lipopeptides: Polymyxin B
which ABX treat mycobacteria?
- anti-mycolic acid: Isoniazid (synthesis) and Ethambutol (incorporation).
- Rifamycin: Rifampin. (red tears)
nitrofurantoin
protein synthesis inhibitor.
fully synthetic + broad spectrum
prodrug - must be activated by the enzyme nitrate reductase from the microbe itself. concentrates in urine.
attacks the ribosomal proteins.
can also treat UTI’s.
chloramphenicol
protein synthesis inhibitor.
fully synthetic + broad spectrum
goes after the 50S subunit of the 70S ribosome.
inhibits the polypeptide formation between amino acids.
treats: rickettsial diseases like lime disease.
side effect: suppresses bone marrow, leading to hemoglobin levels in the blood to drop.
aminoglycosides
protein synthesis inhibitor.
streptomycin* (IV and injection), neomycin (tropical in neosporin), gentamycin.
broad spectrum, goes after the 30S subunit of the 70S chromosome.
targets the amino acid sugars linked by glycoside bonds.
side effect: auditory damage. tinnitus.
tetracycline
protein synthesis inhibitor.
broad ABX.
interferes with tRNA attachment. (binds the amino acid to mRNA)
treats: chlamydia and richetssia.
penetrates tissue.
macrolides
protein synthesis inhibitor.
Erythromycin.
narrow! gm (+)
PCN G alternative
blocks the ribosome tunnel, preventing mRNA from being translated into a protein.
carbapens
inhibit cell wall synthesis.
Impinem/Cilastatin
Primaxin.
broadest spectrum and last line agent.
Cilastatin prevents the ABX from being degraded in the kidneys.
monobactam
inhibit cell wall synthesis.
Aztreonam
fully synthetic. very narrow gm (-)
ONLY GM (-) BACILLI.
injection only.
polypeptide ABX
Bacitracin and Vancomycin
narrow. gm (+)
MRSA
phenolics
cresol and ophenylphenol
disinfectant
biphenols
disrupt the plasma membrane
hexachlorophene and triclosan
in hand soaps and lotions
disinfectant
biguanides
disrupt the plasma membrane
chlorhexidine
antiseptic
used in surgical hand scrubs
halogens
impair protein synethsis and disrupt the plasma membrane
- iodine: tincture and iodophors
- chlorine: water sanitization and disinfecting. bleach and chloramine
