Chapter 16 Antimicrobials (diana's version) Flashcards
how does antimicrobial drugs acts?
usually act by interfering with the growth of microorganisms
Unlike disinfectants these must work inside of the patient and therefore should exhibit selective toxicity
antimicrobial drugs
what is selective toxicity again?
damage the pathogen without harming the host
Antimicrobial rugs:
spectrum of antimicrobial, what are the two options?
Spectrum of antimicrobial activity:
1.narrow spectrum
2.broad spectrum
what is a narrow spectrum
the drug is only effective against a limited range of microorganisms
set an example, of narrow sepctrum
penicillin G affects mainly gram positive bacteria
what is a broad spectrum drug
the drug affects a wide range of organisms
what is the advantage of broad spectrum and what is the disadvantage?
advantage: these drugs are useful when the identity of the organism is unknown
disadvantage: these drugs are bad for normal microflora
set an example for broad sepctrum
tetracycline affects both gram positive and gram negative
this is targetting one specific thing and not anything else
narrow
less bacteria being harmed, lessen the risk of opportunistic pathogen, is this true?
true
vitamin k is important for??
blood clotting
antibacterial agents:
if the drug kills bacteria it is reffered to as what?
bacteriocidal
antimicrobial agents:
if the drug inhibits the growth of bacteria it is referred to as
bacteriostatic
cell wall active agents:
inhibition of cell wall synthesis:
target peptidoglycan synthesis
without peptidoglycan bacteria that try to grow will lyse
only works on organisms that are actively growing
peptidoglycan is only found in bacteria
excellent selective toxicity
these are most frequently used class of antimicrobial drugs
cell wall active agents go after what ?
they go after cell wall and target peptidoglycan
you are putting something foreign particle inside of your body, however it is an excellent selective toxicity, not going after you
cell wall synthesis
you want them to burst , no where in your body that are harming, the outcome is not harming your tissues
cell wall synthesis
cell wall active agents
Penicillins and Cephalosporins :
Group of 50 antibiotics
penicillins are naturally found antibiotics
all contain a core chemical structure : beta-lactam ring
prevent peptidoglycan cross linking
penicillin G, amoxicillin, ampicillin, methcillin
this is semi synthetic - a little bit fake
even bug makes the b lactamase the drug is resistant to b lactamese activity- the outcome is that drug will still work
cell wall active agents
what does prevent peptidoglycan cross linking
NAM-NAG-NAM-NAG-NAM
it’s not made in chemistry lab, made from bacteria microbial antagonism
cell wall active agents
the bug can have a gene to make B lactase enzyme - he can breaks it open
B lactam
is penincillin a broad beta lactamase? or narrow
broad lactamase
true or false many bacteria can resists penicillin by producing penincillinases referred to as beta-lactamases
true
define the characteristics for penincillins
these are some semi synthetic penicillins which are synthetically modified penicillins designed to resist destruction penicillinases
example : methicillin
bacteria have adapted to even synthetic penicillins
example : methicillin resistant staphylococcus aureus
target wall that have beta
cephalosporins
another category of cell wall activation that has the beta
cefixime, cephalothin
this is polypeptide (this is like a short amino acid sequence protein ) narrow spectrum
bacitracin
is bacitracin narrow or broad?
it is narrow
is bacitracin: polypeptide antibiotic active primarily against gram positive
yes, that is true
name the characteristics for bacitracin
polypeptide antibiotics that works active primarily on gram positive
inhibits peptidoglycan synthesis
-earlier stage of inhibition than penicillins and cephalosporins
-inhibits linear strand formation
also toxic to humans
-only used for topical infections
for example : polysporin
they target nag nam nag nam formation
bacitracin
you do not respond well internally to it
bacitracin
describe the characteristics for vancomycin
glycopeptide
very narrow spectrum for activity
-active against staphylococcus aureus
used as a last resort against MRSA
this is reserve for MRSA
vancomycin
its got amino acid, it has sugar group that is found on the structure
glycopeptide (vancomycin)
this use had led to Vancomycin resistant enterocci (VRE)
vancomycin
Name the characteristics for Vancomycin (VRE)
VRE is an oppurtunistic pathogen causing nocosomial infections
VRE is often resistant to all other antibiotics
VRE loves to transfer resistance genes to other bacteria
when these genes are transferred to MRSA there is nothing left to treat it
urgent situation
protein synthesis inhibitors targets 70 S or 80 s?
70s, they do not target 80s
true or false. when using protein synthesis inhibitors it is indeed targeting ribosomes, however will it do some damage to our ribosomes as well, since we have 70 S ribosomes in our cells?
yes it will, although we have 80s our cells also consists 70S ribosomes.
what are the cell wall synthesis different antibiotics?
- penincillins and cephalorins
2.batricin
3.vancomycin
describe the characteristics for protein synthesis inhibitors
these drugs prevent the translation of proteins
bacteria have 70S ribosomes and Eukaryotes have 80S ribosomes
-mitochondria of eukaryotes also have 70S ribosomes
as a result these drugs can have adverse effects on host cells
true or false. If you turn off protein synthesis , you are preventing a lot of important things
true
in eukaryotes, it has to go through 2 membranes to go through 70S ribosomes in us
true
chloramphenicol (protein synthesis inhibitors) :
this is a bacteriostatic antibiotic
extremely effective
broad spectrum of activity
inexpensive
small
-easily diffuses into areas that are difficult to access
very toxic
occasionally used in eye drops for conjunctivitis
does chloramphenicol stop the growth of bacteria or does it kill them?
it stops the growth of them
is chloramphenicol a localized treatment or systematic?
localized treatment (for eyes) used as an eye drops
aminoglycosides describe the characteristics (protein synthesis inhibitors)
this group of antibiotics are bacteriocidal
they include: gentamycin, neomycin,tobramycin,streptomycin
they bind to the 30s ribosomal unit
this group of antibiotics has a narrow spectrum of activity
true or false. aminoglycosides are very active against gram negative organisms
true
name an example of aminoglycosides
opportunistic pseudomonas species which cause infection in patients with cystic fibrosis
what can be toxic causing damage to the auditory nerve and the kidney?
aminoglycosides
this can cause you to lose your hearing, and also because we have the same ribosome inside of our mitochondria therefore this is toxic, we have to use it in the right concetration
aminoglycosides
tetracyclines and describe it’s characteristics
these drugs are bacteriostatic
they have a very broad spectrum of activity
they penetrate the host tissues well: can be used against chlamydial infections
used to treat UTI’s , gonorrhoea, and syphilis
they can suppress the normal microflora of the intestinal tract (leading to super-infections, yeast infections are most common)
can be toxic to humans causing the yellowing of the teeth in children and liver damage in pregnant women
used in animal feed
what are the two benefits that can come off tetracyclines:
animal does get infected , call sell the animal
this is targeting the positives and negatives (broad spectrum of activity)
tetracyclines
broad spectrum wipes out the good bugs, and common for females is yeast infections
tetracyclines
true or false.
You want to find a good penetrating tissue drug to get into a disease such as chlamydial, can cause reproductive issues if not taken care off
tetracyclines
describe macrolides
erythromycin
azithromycin and clarithromycin: broader spectrum of activity and better tissue penetration
- good for intracellular bacteria such as clamydia spp
these drugs do not penetrate the outer membrane of most gram negative organisms
macrolides, they have a narrow spectrum of activity
-active mainly against gram positive
this is a drug that is wildly use
erythromycin
azitmycin and clarithmycin are usually taken as how?
as a pill , usually (2)
these drugs can cause injury to the plasma membrane
plasma membrane disruption
true or false. The plasma membrane in bacteria is almost identical to that of human cells ?
true
plasma membrane disruption are drugs that can be…
be very toxic
Plasma membrane (polymyxin B):
this drug is bacteriocidal
generally only used in topical treatments
-to prevent systematic damage to human host cells
what is the difference between bacteria and eukaryotes plasma membrane
eukaryotes adds cholesterol
true or false. plasma membrane disruption is neuphrotoxixicty (your kidney is highly infected by this ) filters your blood
true
Inhibition of nucleic acid synthesis:
this group includes rifampin and rifampicin
rifamycins
True or false. As a rifamycin drug, they block trancription , no mRNA is made–> no protein is produced
true
what type of drugs is able to penetrate host tissues, cerebrospinal fluid and abscesses?
rifamycins
True or false. Rifamycins can be used to treat mycobacterial spp (causative agents of tuberculosis and leprosy)
true
this is a anaerobic bubble (protective chamber) filled with junk
abscesses
True or false. All RNA can be made as a result of beings on a rifamycin drugs
false, no rna can be made since transcription is blocked
describe the characteristics of rifamycin
this includes the group rifampin, and rifampicin
they block transcription
- no mrna is made, and no protein are produced
they are able to penetrate host tissues
cerebrospinal fluid and abscesses
used to treat mycobacterial spp
- causative agents of tuberculosis and leprosy
this includes cprofloxacin and inhibits dna gyrase and enzyme needed for dna replication
fluoroquinolones
True or false. Fluoroquinocolones are useful for fighting serious life threatening infections and they can harm cartilage development in children?
true
describe the characterisitcs for fluoroquinolones
include ciprofloxacin
inhibits dna gyrase
-enzymes neededd for dna replication
these drugs are useful for fighting serious life threatening infections
they can harm cartilage development in children
this is good for life threatening and intermediate therapy before giving something else
fluoroquinolones
essential metabolite synthesis inhibtors:
A. sulfonamides
these are synthethic (non natural antimicrobials)
bacteriostatic
structurally similar to PABA
paba is presecur used to make folic acid and which is needed by all bacteria
these drugs bock folic acid
this is primary used in combination of trimethoprim and sulfamethoxadole
sulfonamides (sulfa drugs)
These drugs lost their importance when antibiotics were developed, they are still used sometimes for urinary tract infections and to prevent in burn patients
sulfonamides (sulfa drugs)
Is paba part of the normal synthesis?
yes
true or false. We get presecusor (pholic acid) , we can make amino acids and nucleic acids as we require
but bacteria also makes it (they have all the enzymes to do so)
true
These antibiotics haev a very narrow spectrum of activity since they are only active against mycobacterium
anti-myocobacterial antibiotics
they inhibit the synthesis of mycolic acid found in the cell wall of mycobacterium spp.
anti- mycobacterial antibiotics
name an example of anti-mycobacterial antibiotics
isoniazid used in combination with rifampin to treat mycobacterial infection
using combination therapy increases the likelihood of resistance developing of mycobacterial ?
false, it decreases it
since fungi are also eukaryotes they are very difficult or easy to treat?
they are difficult to treat, since it makes selective toxicity difficult
antifungals agents:
antifungals are agents that affect the sterols within the plasma membrane
fungi have cholesterol and animal have ergosterol
false, it’s the opposite for fungi and animal
targeting ergosterol dramatically decreases membrane permeability-, leading to a stable condition
false, targeting ergosterol dramatically increases membrane permeability, not stable but lethal situation to the organism
what are the two known antifungal agents?
1.Polyenes
2.Azoles
polyenes are fungicidal or fungastatic?
they are fungicidal
which is a neuphrotoxixicty? Polyenes or azoles?
polyenes
Name the characteristics for polyenes
they are fungicidal
they work by poking holes in the fungal membrane
examples include nystatin and amphoteracin B
they can be toxic causing kidney damage
they are used to treat yeast infections and systematic fungal infections
are azoles fungicidal or fungistatic?
they are fungastatic
True or false: azoles interfere with sterol syntehsis
true
name the characteristics for azoles
these are fungistatic
they interfere with sterol synthesis
examples include : miconazole, clotrimazole,ketoconazole
they are use for cutaneous fungaln infections, yeast infections, and systemic infections
they are less toxic than polyenes but may caus eliver damage
this stop mitotic division since they are eukaryote
do not drink alcohol while being on the drug, (or on a bad heatlh of your liver) since it is a hepatotoxicity drug
azoles
other antifungal agents:
grisefulvin is taken ___ but it is active against ____ of the skin and hair
orally, fungal infection
this drug binds to the keratin protein, which interferes with mitsosis
griseofulvin
True or false. Griseofulvin is fungistatic and thus must be taken until he infectrd part is shed
griseofulvin
True or false. If the nail has a fungal infection you do not have to wait for the nail to completely grow out, since the infection is gone by 2-3 days.
false, you have to wait until the nail completely grows out
are antiprotozoan agents : eukaryotes or proakryotes?
they are eukaryotes
name the characteristics of anti-protozoan agents
these drugs have lots of problems with toxicity
there are only a few major differences between human cells and protozoa
there are very few drugs available and they are usually specific for one protozoan
Antiprotozoan agents:
Quinine
is an anti malarial drug
interferes with the DNA replication of malaria
Antiprotozoan agents:
Metronidazole
also called flagyl
inhibits the metabolic process of fermentation in anaerobes
used against giardia lamblia (beaver fever)
also used against fermentative bacteria and yeasts
Is it true that antibiotics are effective against viruses?
no, that is false, antibiotics are not effective against viruses
In the developed world ___ of infections are viral
60% of infections
True or false. Very few antivirals are available and most are specifically used to treat what?
this is true, and specifically used to treat HIV
What does antibiotics do in terms of being an antiviral agetns?
interfering the replication-minimizing the consequences
Cocktail of drugs is used against___, but cannot get rid of it and this wont pass the placenta or breastmilk and never the intention to clear -= it is just not possible
HIV
what are the three antiviral agents known
nucleoside and nucleotide analogs
interferons
enzymes affecting assembly and release of virus particles
what is the characteristics of nucleoside and nucleotide analogs?
acyclovir: blocks replication in herpes infections
-used to treat genital herpes
AZT: a cocktail of drugs that inhibit DNA synthesis by HIV
this lessens the intensity of the outbreak (herpes) and minimizes how bad it gets
nucleoside and nucleotide analogs
Viral load - is reduced by this type of theraphy and not the real deal (missing something)
nucleoside and nucleotide analogs
this is made by a virally infected cells (got a virus inside) nothing to stop it (like alarming system) but it warns the other cells
interferons
are interferons much like naturally produced
yes
True or false. Interferons does not have any side effects.
false, it has many side effects
These stimulate cells to produce antiviral proteins
interferons
used as a drug of choice for hepatitis infections
interferoons
name the characteristics for interferons
these are much likely naturally produced interferons
they have many side effects
stimulate cells to produce antiviral proteins
used as a drug of choice for hepatitis infections
enzymes affecting assembly and release of virus particle:
protease inhibitors:
Neuraminidase inhibitors:
used to treat HIV infection
used to treat influenza
example: tamiflu, ralenza
this is like a peeler allows virus t get off the cell and find an naive cell(healthy ell) and go after that
neuronamidise inhibitors
true or false. Neuraminidise inhibitors reduced severe flu
true
is it true that enzymes affecting assembly and release virus particles not affecting dna or rna
true
Antibiotic resistance:
there are four common mechanisms of antibiotic resistance. True or false?
true
- drug inactivation by microbial enzymes
ex: beta lactamses such as penincillinase
- decreased drug uptake:
antibiotics are kept from reaching the target
3.Altered drug uptake
the antibiotic target is altered by mutation
4.removal of antibiotic from the cell
once the drug enters the cell it is ejected by efflux pump
Antibiotic resistance genes are often carried on ___ plasmids, are these plasmids easily transferred to other bacteria?
r plasmid, yes they are easily transferred to other bacteria
a drug that can produce beta lactamses can inhibit what?
peptidoglycan
this is a pump that takes the bug where it came from, not specific to one (as long as they fit) psh them right back = protective
efflux pump
this is also specific again =,altered target, inactive drug
altered drug target
