Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Bacteria > Antimicrobial Chemotherapy > Flashcards

Antimicrobial Chemotherapy Flashcards

(59 cards)

Start Studying
1
Q

Benzyl penicillin’s

A

Inhibit cell wall synthesis
Beta lactam
Bactericidal
Mainly effective against gram positive bacteria
Gram negatives are widely resistant

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

Cephalosporins

A

Inhibit cell wall synthesis
Bactericidal
Second large group of beta lactams

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

What is the mechanism of beta lactams?

A

They inhibit peptidoglycan synthesis by inhibiting the enzymes (penicillin binding proteins) that cross link the carbohydrate chains of the peptidoglycan cell wall.

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

Glycopeptides

A

Group of antibiotics that inhibit cell wall synthesis
Bactericidal
Only act on gram positive organisms
Act on cell wall synthesis a stage prior to beta lactams
Inhibit assembly of a peptidoglycan precursor
Only given parenterally

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

Vancomycin

A

Glycopeptide
Toxicity is common
I.V. infused and carefully monitored

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

Teicoplanin

A

Glycopeptide
Less toxic than vancomycin

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

Aminoglycosides

A

Inhibit protein synthesis
Concentration dependant bactericidal antibiotics
Useful in treating serious gram-negative infection

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

Mechanism of aminoglycosides

A

Inhibit protein synthesis
Acts only on bacterial protein synthesis due to differences in bacterial and mammalian ribosomes.
Binding impairs the proofreading of translation leading to mistranslation of the RNA message and inaccuracy of the translated protein product.

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

Gentamicin

A

Aminoglycoside
Toxic and requires a careful dosing regime and close monitoring.

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

Macrolides

A

Inhibit protein synthesis
Bactericidal or bacteriostatic
Useful in treating gram positive infections when patient has a penicillin allergy

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

Macrolide mechanism

A

Inhibit protein synthesis
Prevent peptidyltransferase from adding the growing peptide attached to tRNA to the next amino acid
Also inhibits ribosomal translation

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

Erythromycin

A

Example of a macrolide

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

Tetracyclines

A

Inhibit protein synthesis
Batceriostatic antibiotics
Treats gram positive infections
A significant percentage of staph. and strep. strains are resistant

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

Mechanism of tetracyclines

A

Tetracyclines prevent the introduction of new amino acids to the nascent peptide chain

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

Oxazolidinones

A

Inhibit protein synthesis
Bacteriostatic or bactericidal dependant on the bacteria being treated
Usually treat gram positive infections

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

Linezolid

A

Oxadolidinone
Only antibiotic in this class in common use
Generally reserved for serious infections

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Cyclic lipopeptides

A

Inhibit protein synthesis
Strong bactericidal agents
Treat gram positive infections

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Daptomycin

A

Cyclic lipopeptide
Acts against gram positives and MRSA in particular
Alters the curvature of the membrane, causing holes that leak ions, deplarization and bacterial cell death

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Purine synthesis inhibitors

A

Inhibit nucleic acid synthesis
Bacteriostatic and bactericidal when combined
Inhibit DNA synthesis directly or by interrupting precursors for DNA synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Trimethoprin and sulphamethoxazole

A

Often used in combination as co-trimoxazole
Does not predispose C.difficle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Fluroquinolones

A

Bactericidal
Inhibit nucleic acid synthesis
Particularly effective against gram negative organisms
Inhibit DNA synthesis more directly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Ciprofloxacin and levofloxacin

A

Fluroquinolones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the two types on antibiotic resistance

A

Inherent and acquired

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Inherent resistance

Study These Flashcards
A

When all strains of a given species are resistant to an antibiotic
Streptococci are always resistant to aminoglycosides
Gram negative organisms are always resistant to vancomycin

25
Acquired resistance
May be present in certain strains but not others Laboratory sensitivity testing is required to establish the sensitivity of the patients bacterial isolate
26
What is antibiotic resistance a good example of?
Natural selection
27
Two ways that resistance is acquired
1) Spontaneous mutation 2) Genes that code for resistance can be spread from organism to organism or species to species Genes can be carried on plasmids or transposons
28
Conjugation
DNA transfer between bacterial cells
29
Transformation
Naked DNA uptake by bacteria
30
Transduction
Bacterial viruses transferred by viruses
31
Beta lactamases
Enzymes produced that cleave the beta lactam ring of an antibiotic and thus render it inactive
32
Where are beta lactamases most often seen?
In most hospital strains of staph. aureus and also in many gram-negative bacilli
33
Two ways of combatting beta lactamase
1) Modify the antibiotic side chain to include a beta lactamase inhibitor 2) Introduce a second compartment to the antibiotic (beta lactamase inhibitor) protecting the antibiotic from enzymatic degradation
34
Co-amoxiclav
Amoxicillin plus beta lactamase inhibitor clavulanic acid
35
Flucoxaicillin
Modified form of penicillin that resists beta lactamase
36
Extended spectrum beta lactamases
Enzymes that mediate resistance to extended spectrum cephalosporins Antibiotic resistance transferred by conjugation
37
Carbapenemase-producing enterobacteriaceae
Bacteria resistant to carbapenem family of antibiotics by producing carbapenemase
38
Carbapenem Resistant Enterobacteriaceae
Bacteria resistant to carbapenem family of antibiotics by any mechanism Serious problem as this sometimes leaves no options for antimicrobial therapy.
39
What mechanism has MRSA developed to become multi-drug resistant?
It has developed resistance to beta lactams by changing the shape of its penicillin protein binding sites. The PBP changes shape causing a modified binding site that beta lactams can't bind to.
40
What can MRSA be treated with?
Vancomycin or Linezolid
41
Glycopeptide resistance
Before gram positive resistance to glycopeptides was virtually unknown. Recently vancomycin resistant enterococci have been emerging The peptidoglycan precursor that vancomycin usually binds to has an altered structure.
42
Agents used only in UTI's
Nalidixic acid and nitrofurantoin
43
What can cause thrush (overgrowth of candida albicans)
Therapy with penicillin's or cephalosporins
44
Polyenes
Anti-fungal drug Binds to ergosterol, present in the fungal cell wall Active against yeasts and filamentous fungi
45
Amphotericin B
Polyene Only available for IV use and used in serious fungal infections Extremely toxic
46
Nystatin
Polyene Available for topical use
47
Azoles
Anti-fungal drug Inhibits ergosterol synthesis
48
Fluconazole
Azole Oral and parenteral treatment of yeast infections No serious toxicity Some yeasts are resistant
49
Itraconazole
Active against yeasts and filamentous fungi
50
Allylamines
Suppress ergosterol synthesis Anti-fungal Only allylamine used is terbinafine which is active against dermatophyte infections of the skin
51
Echinocandins
Anti-fungal Inhibit the synthesis of glucan polysaccharide in several types of fungi Only used in serious candida and aspergillus infections
52
Nucleoside analogues
Most anti viral drugs Interfere with nucleic acid synthesis
53
Aciclovir
Nucleoside analogue Anti-herpes virus drugs Specific for virus infected cells Active against herpes simplex and varicella zoster
54
Valaciclovir, famciclovir, valganciclovir
Anti-herpes virus drugs
55
Herpes viruses
Herpes simplex, CMV, varicella-zoster, epstein-barr virus
56
Zidovudine
First anti-HIV drug
57
How do we usually treat HIV now?
Combination therapy with at least 3 drugs Drugs active on at least 2 different stages of HIV replication 2 nucleoside analogue reverse transcriptase inhibitors plus a non-nucleoside reverse transcriptase inhibitor or a viral protease inhibitor
58
Interferon-A, ribavirin, adevofir dipivoxil
Drugs for chronic hepatitis B and C
59
Drugs for viral respiratory infections
Zanamivir, oseltamivir, ribavirin

Bacteria (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions