Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Life sci exam 1st term > Antibiotics > Flashcards

Antibiotics Flashcards

1
Q

Penicillin

A

cell wall inhibitor
b-lactam ring
treats gram +
form of penicillin v and g, amoxicillin, ampicillin
safe in pregnancy
is resistance
no selective toxicity
frequent doeses needed
people can have allergies, decreases effectiveness of birth control

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Cephalosporins

A

cell wall inhibitor
b-lactam ring
treats gram + and -
form of cefotaxime
parental oral administration
2nd choice for gbs, 1st for gonorhea, given before/after surgery
-preg safe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Glycopeptides

A

cell wall inhibitor
bactericidal form
treats c dif and staphylococcus aureus
form of vancomycin
consider if bactera are b-lactam resistent or allergy
-preg safe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Aminoglycosides

A

protein synthesis inhibitor
gram - aerobes
form of streptemycin, necmycin, gentamicin
not pregnancy safe
nototoxic and nephrotoxic to baby
administered as intramuscular IV
resistance does exist

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

-cycline

A

prevents trna binding
baacteriostatic
treats chlamydia and mycoplasma
form of tetracycline and doxycycline
not pregnancy safe tertatogenic
administered orally
has resistance
avoid use in children younger than 8, can stain teeth, gut alleric reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

eryhthromycin

A

prevetns trna release
bacteriostatic
treats uti, chlamydia, mycoplasma
is pregnancy safe
given orally or IV
has resistance
used for PROM
macrolide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

azithromycin

A

prevents trna release
bacteriostatic
treats utis
pregnancy safe
has resistance
no selective toxicity
consider penetrates most tissue and slow release
macrolide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

lincosamides

A

inhibits peptide formation
teats bacterial vaginosis, GBS, chlamydia and gonnorhea
form of clindamycin
pregnancy safe
has resistance
cause diarhea nausea rash colitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

quinolones

A

inhibit dna
bacteriacidial
treat utis, chlamydia, gonorrhea
not pregnancy safe
given orally
some resistance
cause vommiting, nasuea abdominal pain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

sulphonamides

A

folic acid inhibitor
bacteriostatic
gram -
treats utis
not pregnancy safe
given orally
has resistance
has selective toxicity
not safe for newborn or pregnancy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

metronidazole (FLAGYL)

A

-against anaerobes
-dna inhibitor
treats protozoal infections
preg safe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Ideal antimicrobial:

A

-hard for pathogen to develop antibiotic resistance to
-broadspectrum (kills all organisms including microbiome) vs target antibiotics (ex. Only gram negative bacteria)
-different administration - needle/IV vs taking a pill
-something that is stable in multiple temperatures (thermostable)
-easily readable and inexpensive
-lethal to pathogen or at least inhibits its growth
-harmless to person
-no allergens or toxicity
-long half life (less frequent dosing)
-low plasma-protein binding (stays in its form, can penetrate, work stronger, does intererfere with other things)
-no interference with other drugs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Antibiotic Resistance:

A

-not be inhibited or killed by an antibacterial agent

-can happen from the synthesis of new or altered proteins by the microorganism

–Single chromosomal mutation: single amino acid change → lowers affinity (degree of killing) to antibiotic

–Series of mutations: changes on penicillin binding proteins → penicillin resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Mechanisms of Resistance:

A

-Altered target site: Drugs need to bind a particular receptor/site. This lower affinity of the target for the antibacterial. Receptor/site still functions for cell processes

-Altered uptake/increased efflux: Reducing the amount of drug that reaches the target (decreasing cell wall permeability, pumping drug out of cell)

-Drug inactivation:
-Enzymes that modify or destroy the drug
-E.g. Penicillin-β lactamases made be bacteria break down beta lactam ring so it can’t work

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Ways HCPs can Prevent Antibiotic Resistance:

A

-only prescribing when necessary - can sometimes see if infection clears on its own
-making sure people take the full course of antibiotics and not stopping if they feel better
-choosing narrow spectrum antibiotics when possible
-confirm its a bacterial infection before prescribing antibiotics
-make sure people NEVER share antibiotics and never using leftover antibiotics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Ways to Classify Antibiotic

A

1.Bactericidal or Bacteriostatic
–Bactericidal → Kills a microorganism
–Bacteriostatic → Halts the growth of microorganisms, the immune system can then eliminate them (Not effective if immunity is suppressed)

2.Mechanism of action

3.Chemical structure
–Not of practical use when used alone
–When combined with target site can be useful to organise antimicrobial agents into specific families

17
Q

Bactericidal vs. Bacteriostatic (1/ways to classify antibacterial agents)

A

-Bactericidal
–E.g. penicillin can cause holes in the cell walls of bacteria, so they die

-Bacteriostatic
- E.g. tetracycline or erythromycin keep bacteria from dividing further by inhibiting protein synthesis necessary for division

18
Q

Mechanism of Action (2/ways to classify antibacterial agents)

A

A) Cell wall synthesis
B) Protein synthesis
C) Nucleic acid synthesis (DNA, Folic acid synthesis inhibition

19
Q

Antibiotic resistant methods

A

Efflux Pumps: Bacteria can have pumps that actively remove macrolides from inside the cell, reducing their concentration and effectiveness.

Target Modification: The target of macrolides in bacteria is the ribosome, where they interfere with protein synthesis. Resistance can occur when bacteria modify their ribosomes, making them less sensitive to macrolides.

20
Q

Antifungal Agents:

A

-few in number
-selective toxicity is difficult (fungi are eukaryotes, like human cells)
-have ergosterol - a lipid in fungal membranes (humans have cholesterol)
-some times no single antifungal is ideal (ringworm infection of the nails or recurrent vaginal candidiasis are frequently intractable)
-resistance occurs

21
Q

Azoles or Imidazoles:

A

-Inhibits cell membrane synthesis (ergosterol)
-Small molecule, easily absorbed
-Clotrimazole (Lotrimin) and miconazole (Monistat) are useful topical preparations
-Fluconazole used increasingly to treat Candida (avoid in 1st trimester especially)*
-Ketoconazole (Nizoral) is the agent of choice for serious infections*
-issues in pregnancy

22
Q

Polyenes:

A

-amphotericin B and nystatin (mycostatin)
-inhibit cell membrane function:
-bind to cell membrane and cause leakage of cell products and cell death (breaks ergosterol and not cholesterol)
-selective toxicity because humans do not have the binding site
-used to treat serious systemic fungal infections
-Amphotericin B given IV, orally, or topically
Used to treat serious infections
Side effects: fever, nausea, malaise, chills
*Safe during pregnancy (category B)
-Nystatin topical only (category A)
Used to treat Candida in mouth, mucous membranes (vaginal)
Athlete’s foot (cutaneous mycosis)
Minimal side effects

23
Q

Vaccines

A

-active immunisation - the adaptive immune system responds to antigens in the vaccine a produces memory B and T cells.
Antibodies generated by vaccination (or repeated vaccination) are directly available to fight the pathogen when an infection occurs

-Passive immunisation is provided by antiserum or other immunoglobulin (what B cells would normally make) based treatments that provide antibodies to protect from (or treat) infection, but do not induce memory response, and provide only temporary immunity

24
Q

Basic Types of Approved Vaccines (6 total types- 8 with new COVID Vaccines):

A

1.Live attenuated
2.Inactivated (primarily good at inducing antibodies)
A) Whole
B) Fractional:
1. Subunit
2. Toxoid
3. Polysaccharide based- Whole/conjugate

3.mRNA *
4.Viral-vectored*

25
Q

Live Attenuated Type Vaccine Examples:

A

-contained weakend (attenuated) form of pathogen
-such as MMR measles, mumps rubella, and varicella zoster (chickenpox)
-cause symptoms (full immune effect) not for immunocompormised

-most are given intramuscular, sometimes subcutaneous, sometimes oral (less common), intranasal is a new concept

26
Q

Inactivated Whole Vaccine:

A

-killed (innactivated) using heat/chemicals pathogen
-hep a vaccine, influenza vaccine, rabies
-boosters needed not as strong as attenuated
-all subcutaneous or intramuscular currently

27
Q

Subunit, Recombinate and Conjugate Vaccines

A

-Vaccine contains specific protein antigens from the microorganism that can elicit an immune response

1.Influenza Vaccines: isolated surface hemagglutinin and neuraminidase proteins

-all subcutaneous or intramuscularRecombinant Protein Vaccines Against Human Papilloma Virus (HPV):

28
Q

Recombinant Protein Vaccines Against Human Papilloma Virus (HPV):

A

-Gardasil: recombinant capsid proteins, from several strains of HPV in aggregated particulate form, with adjuvant
-Given i.m. with adjuvant, repeated 3x for maximum effect
-IgG antibody to protect reproductive tract, female and male
-Side effects: mild and typical for i.m. injected killed/protein vaccines with adjuvants
-Considered safe in pregnancy – a clinical trial showed no higher frequency of foetal abnormalities BUT currently not recommended due to limited data

29
Q

Inactivated Vaccines risk benefit

A

-benefits:
Stable- No risk of mutation
Possible for bacteria or virus (not toxoid/polysaccharide for virus)
Very little chance of adverse reactions (specific reactions except whole inactivated option)
-negatives:
Does not replicate so usually only antibody mediated responses are induced- usually weaker than from live attenuated (but this may be all you need!)
Require repeated doses (boosters)
Need adjuvant or to conjugate (polysaccharide)
Identification of best antigens for subunit vaccines may be difficult or impossible

30
Q

Adjuvants for i.m. Vaccines- Inactivated- whole/subunit vaccines:

A

-adjuvant means ‘to help’
-immunologic adjuvant = any substance that acts to accelerate, prolong, or enhance antigen-specific immune responses when used in combination with specific vaccine antigens

-For humans, nearly all injectable, intramuscular (i.m.) vaccines contain aluminium salts as adjuvant

-Aluminium salts cause local inflammation in injection site
-Albumin salts can bind to the antigen and prolong its exposure to immune cells
-Typically provided increased IgG antibody response
-Small risk for side effects: fever, pain at injection site, headache

-Adjuvants work by stimulating local tissue inflammation, and activating dendritic cells that then migrate to lymph nodes and present antigen to CD4 T cells

31
Q

mRNA Vaccines:

A

-mRNA encapsulated in a lipid nanoparticle to protect it from degradation
-Take up by APC, mRNA enters cytoplasm and makes spike protein
-Immune response to spike develops
-mRNA broken down after used
-Not approved for use prior to COVID
-RARE SIDE EFFECTS Pfizer/Moderna COVID Vaccine: myocarditis, Bell’s palsy

32
Q

Recombinant Viral Vector Vaccine:

A

-harmless virus (vector) modified to carry pathogen material
-host cells start following viral dna but its not hurful
-immune reposne recongizes the cells as foreign and launches immune response

-RARE SIDE EFFECTS Astrazeneca/Johnson Johnson COVID vaccine: Vaccine induced thrombocythemia (blood clots), Guillain Barre Syndrome

33
Q

cell wall inhibitor

A

-bacteria has cell wall as protective layer
-their cell wall is made of peptidoglycan made by bacterial enzymes
-cell wall inhibitor anitbiotics interefere with peptidoglyca enzymes so cell wall is weak

34
Q

beta lactam rings

A

-3carbons and a nitrogen
-targets penicilin binding proteins PBPs bi binding to them
-weaken cell wall
–Cleavage of the ring by penicillinases (β-lactamases) inactivates the drug
-Need frequent doses for most B-lactams
-We have developed drug defences against β-lactamases through inhibitors such as clavulanic acid and sulbactam
-penicillin allergies (true anaphylaxis) are very rare but serious

35
Q

Jeopardy

A

GBS treatment:
-penicillin, cephalosporins, erythromycin

Chylamydia:
pregnancy - lincosamides or macrolides
no pregnant - tetracylcines

Gonnorhea:
penicillin, cephalosporins, lincosamides

MRSA (staph aureus):
vancomycin (glycopeptide)

Streptococci:
penicillin, cephalosporins, macrolides

36
Q

Pregnancy safe antibiotics

A

Life sci exam 1st term (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions