Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

VET302! > Anti-biotics > Flashcards

Anti-biotics Flashcards

(63 cards)

Start Studying
1
Q

Main anti-bacterial target of BETA LACTAMS

A

Inhibitors of cell wall synthesis

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

Main anti-bacterial target of AMINOGLYCOSIDES, TETRACYCLINES & MACROLIDES

A

Inhibitors of transcription and translation

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

Main anti-bacterial target of SULPHONAMIDES & FLUROQUINOLONES

A

Inhibitors of DNA synthesis AND integrity

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

What are the 3 main mechanisms of resistance by beta lactams?

A
  • Gram-Negative Cell Wall Barrier
    Beta-lactams generally work better on Gram-positive bacteria.
    Gram-negative bacteria have a less permeable outer membrane, making it harder for beta-lactams to penetrate and reach their targets.
    This is not a dead-end resistance—some beta-lactams can still get through.
  • Beta-Lactamase Enzymes (including Penicillinases and Cephalosporinases)
    These enzymes break down beta-lactam antibiotics via hydrolysis.
    The term “beta-lactamase” is broad and can refer to:
    Enzymes that destroy only penicillins (penicillinases)
    Or enzymes that destroy all types of beta-lactams
  • Altered Penicillin-Binding Proteins (PBPs)
    Seen in organisms like MRSA (methicillin-resistant Staphylococcus aureus)
    These bacteria have PBPs with reduced affinity for beta-lactams.
    This is a “dead-end” resistance:
    It cannot be overcome by increasing the drug dose or frequency.
    Beta-lactams simply cannot bind effectively to the altered PBPs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How can we regain efficacy against Beta-Lactamase Enzymes (one of the mechanisms of resistance) produced by bacteria?
Give an example

A

Use a second beta-lactam that will irreversibly bind to the beta-lactamase and therefore spare the first (more clinically efficacious) beta-lactam
Eg. Clavulanic acid is the most commonly used beta-lactamase inhibitor
– e.g. amoxycillin – clavulanic acid - the amoxycillin may still be able to work despite the presence of beta-lactamase
– e.g. piperacillin – tazobactam

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

Toxicity of beta lactams?

Side effects?

Allergies?

A
  • Usually safe: can be used in geriatrics, juveniles, pregnancy and during lactation
    why? - MOA is on the cell wall, animals don’t have a cell wall therefore they are very safe!
  • Side effects
    Usually come about through a dysbiosis
    Killing good bacteria, recolonisation by a monomorphic population, toxins, GIT signs
    Diarrhoea, vomiting most common
    Small herbivores – could be more of an issue for herbivores due to their effects on the microbiome in their gut (effects adults more than young)
    Accidental IV with some preparations
  • Allergies- seems to be a human problem only
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Why do you have do be careful when administering beta lactams to small herbivores? (ie exotics)

A
  • Disruption of intestinal floral population –> clostridial and/or coliform proliferation = exotoxin release
  • especially when given orally – higher GIT concentrations – therefore killing more bugs
  • instead administer parenterally – relies on distribution - therefore diluted!
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Benzylpenicillin
- Kind of drug?
- What route can it be given?
- Diminished effect against what?

A
  • Beta Lactam - Natural penicillin - SAs & LAs
  • Can be given IV
  • Diminished effect against beta lactamase producing bacteria
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Procaine penicillin
- Gram and oxygen usage
- Against beta lactamase producing bacteria?
- NEVER give via what route?
- Procaine part?

Procaine penicillin + Benzyl penicillin (“Norocillin LA”, “Duplocillin”, “Benacillin”)
- What is the benefit of these preparations?

A
  • Beta Lactam - Natural penicillin - LAs
  • Gram pos and anerobic coverage
  • Does NOT work against beta lactamase producing bacteria?
  • NEVER IV!
  • Procaine - prolongs DOA

Procaine penicillin + Benzyl penicillin
- benzathine and procaine - are insoluble therefore make the DOA of penicillin longer!

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

Penethamate
- Kind of drug?
- Good for what?

A
  • Beta Lactam - Penicillin
  • Alkaline penicillin that will concentrate and persist in the acidic udder
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Ampicillin
- Kind of drug?
- What route can it be given?
- Diminished effect against what?

A
  • Beta Lactam - Aminopenicillin - SAs
  • Can be given IV
  • Diminished effect against beta lactamase producing bacteria
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Amoxycillin
- Kind of drug?
- What route can it be given?
- Diminished effect against what?

A
  • Beta Lactam - Aminopenicillin - SAs
  • Can be given IV
  • Diminished effect against beta lactamase producing bacteria
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Cloxacillin
- Kind of drug?
- Route of administrations (2)

IMM
- Selection of IMM preparation will be based on
- Important to never….

Ointment
- Used primarily for what, mainly in what species?

A
  • Beta Lactam - Beta-lactamase stable penicillin - SAs & LAs (mainly)
  • Intramammary (IMM) or ointment (for eyes)

IMM
- Selection of IMM preparation will be based on
> vet, farmer personal preference
> cost of antibiotic
> C&S
> milk WHP
- Important to never give a dry cow therapy to a lactating cow!

Ointment
- Used primary for bacterial keratoconjunctivitis (pinkeye) in cattle, not effective in sheep
- registered for cattle, sheep, horses, dogs and cats

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

Amoxyclav-clav acid (“Clavulox”, “Amoxyclav”)
- Kind of drug?
- Gram?
- Oxygen usage?
- Never give via which route of administration?
- Why is it only registered for calves and not cows?

A
  • Beta Lactam - Aminopenicillin - SAs
  • Gram pos and anaerobic coverage
  • Still works against beta lactamase producing bacteria
  • Never IV!!
  • technically monogastric, not ruminants yet
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Piperacillin-tazobactam
- What kind of drug?
- Important point? - Use after what?

A

*Extended spectrum penicillin’s with beta lactamase inhibitors
- Beta Lactam - Extended spectrum penicillin - SAs
- Special use antibiotic
- Use after you’ve done culture and susceptibility

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

Ticarcillin - clav acid
- What kind of drug?
- Important point? - Use after what?

A
  • Beta Lactam - Extended spectrum penicillin - SAs
  • Special use antibiotic
  • Use after you’ve done culture and susceptibility
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Cefazolin
- Kind of drug?
- What route can it be given?
- Diminished effect against what?

A
  • Beta Lactam - 1st gen cephalosporin - SAs
  • Can be given IV
  • Diminished effect against beta lactamase producing bacteria
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Cephalexin
- Kind of drug?
- Gram?
- Good for what?

A
  • Beta Lactam - 1st gen cephalosporin - SAs
  • gram pos
  • good for staph pyoderma (skin infection)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Cefovecin
- Kind of drug?
- Gram?
- Good for what?

A
  • Beta Lactam - 3rd gen cephalosporin - SAs
  • gram neg, decreased efficacy for gram pos BUT still good for staph!
  • good for skin (eg staph), urinary (eg. e.coli), dental conditions (eg aerobes)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Ceftiofur
- Kind of drug?
- Gram?
- Good for?

A
  • Beta Lactam - 3rd gen cephalosporin - LAs (horses & production animals)
  • gram neg, decreased efficacy for gram pos BUT still good for staph!
  • good for many respiratory infections
  • in cows good for septicemia given systemically - does not distribute into an udder very well! Hence 0d milk WHP
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Ceftazidime
- What kind of drug?
- Gram?
- Important point? - Use after what?

A
  • Beta Lactam - 3rd gen cephalosporin - SAs
  • gram neg, decreased efficacy for gram pos BUT still good for staph!
  • Special use antibiotic
  • Use after you’ve done culture and susceptibility
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What route are aminoglycosides best given?
What are their issues with toxicity?
How should you dose to avoid this?

A
  • Poor oral absorption! so if given orally will only effect the gut
    Give IV
  • Toxicity - struggles to get across fatty membranes/plasma membranes - get stuck! - places with lots of fatty stuff ie ears and kidneys
    = ototoxicity
    = nephrotoxicity
  • Give large infrequent doses (rather than small frequent doses)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is important to note for food producing species and aminoglycosides?

A

*INJECTABLES PROHIBITED IN FOOD PRODUCING SPECIES! *
Only poor absorption administration to be used ie IMM or PO in cattle!

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

Gentamicin
- Kind of drug?
- Common in what species?
- Do not use in what species?

A
  • Aminoglycoside
  • Common use in horses
  • Do NOT use in food producing species
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Neomycin - Kind of drug - Still in some what preparations? - Out of date - why?
- Aminoglycoside - Still in some ear and eye med - Quite old, lots of resistance - bit out of date
26
Amikacin - Kind of drug - Disadvantage that ends up being an advantage?
- Aminoglycoside - Expensive therefore not used much - therefore less resistance - therefore safer!
27
MOA of the fluroquinolones
Inhibit DNA gyrase leading to breaks in bacterial DNA and cell death --> bactericidal
28
Do NOT use fluroquinolones for what species in Australia?
Food producing!!! - human health concerns regarding emerging resistance
29
Toxicity from fluroquinolones? Avoid its use in animals with what type of growth?
- Quite safe - Uncommon - most common is mild GIT upset - CNS stimulation at very high doses! - so avoid IV use - other routes have slower absorption - Avoid use in animals that have lots of growth in long bones ie giant breeds, foals = Cartilage deformities - chondrotoxicity
30
Enrofloxacin ("Baytril") - Kind of drug? - Don't exceed on label dose for what species? - Dont use in what animals (young or old?) - Do NOT use in what species? - Used commonly in what group of animals?
- Fluroquinolones - DO NOT EXCEED on label dose for CATS! = retinal degeneration - DONT use in young animals (esp with long bone growth)- chelates Mg and chondrotoxicity (= cartilage deformities) - Do NOT use in food producing species! - Used commonly in exotics with Baytril deficiency
31
Marbofloxacin - Kind of drug - Use is based on what?
- Fluroquinolones - Use is based on C&S
32
Pradofloxacin - Kind of drug - Use is based on what?
- Fluroquinolones - Use is based on C&S
33
What are tetracyclines the gold standard for? and have good activity against?
- Chlamydia - Mycoplasma and Rickerrsia
34
Which route of administration for tetracyclines should be used for horses and ruminants?
Parenteral - due to severe GIT flora disturbances
35
Name 2 side effects of tetracyclines
- GIT upset - Nephrotoxicity - Chelation with cations (esp Ca) - can result in drug accumulation in areas of high Ca
36
Oxytetracycline - What kind of drug - Used for - Issue with one of the preparations
- Tetracycline - NO 1 choice for ruminants - Used for mastitis IMM, pink eye (powder and spray preparations) (but gold standard for pink is cloxacillin) - long acting formulation - oily vehicle - given IM - painful, multiple injection sites - can form sterile abscesses
37
Doxycycline - What kind of drug - Benefits - Issues - Often used to treat what in birds?
- Tetracycline - Safest of the tetracyclines - Benefits - palatable, ease of administration (paste), compliance - Issue - expensive - Treat avian chlamydiosis - but is a difficult dx to treat! - water preparations makes water unpalatable ("Psittavet")
38
MOA of the lipoamides and trimethoprim
Inhibit the synthesis and conversion of folate (required by bacteria!)
39
What are sulphonamides coupled with the make them go from bacteriostatic to bactericidal?
Coupled with trimethoprim
40
What is a big issue with the sulphonamides? What are 2 side effects in specific breeds?
- Resistance! - Doberman - Hypersensitivity = hepatic necrosis, glomerulopathy, polymyositis, polyarthritis, skin rash, fever - KCS - Keratoconjunctivitis
41
(Trimethoprim)-sulfadiazine - What kind of drug - Multiple preparations different preparations - one is an exception to rule, the other is good for what?
- Sulphonamide - Different preparations One of the exceptions that white liquid CAN go IV (but is a suspension so = risk of emboli) Power preparation -good take home choice for horse owners
42
(Trimethoprim)-sulfadimidine - What kind of drug - Commonly used for what
- Sulphonamide - powder - Commonly used for cold in horses
43
Silver sulfadiazine ("Flamazine") - What kind of drug? - Widely used for what?
- Sulphonamide - cream - Widely used for burns
44
Drug chemistry of macrolides means it gets trapped where?
In acidic environments
45
Macrolides play a big role in the treatment of what?
Bovine pneumonia
46
Toxicity concerns with macrolides?
- Dont use in adult horses --> GIT dysbiosis --> colitis - Tilmicosin - Human operator toxicity - significant OH&S concerns - Avoid in small herbivores - affects normal anaerobic flora
47
Tylosin - Kind of drug - Suited for what? - Benefit in fairy cattle?
- Macrolide - Suited for footrot, mastitis and resp dx - concentrates in milk - registered for dairy cattle - short milk WHP
48
Tilmicosin - Kind of drug - Should be given my what route of administration, and never? - Not to be used in what food producing species? - Toxicity for operator?
- Macrolide - SC (NEVER IM or IM) - One study suggests its better than ceftiofur and oxytet and florenfenicol for treating BRD - prolonged activity in lungs AND can be bactericidal against pasterurella multocida - NOT to be used in dairy cows - hangs around for too long! - Human operator toxicity - significant OH&S concerns
49
Tulathromycin - Kind of drug - Not to be used in what food producing species? -Should be given my what route of administration for cattle and pigs?
- Macrolide - Registered only for respiratory dx and has 12wk dosing interval - NOT to be used in dairy cows (except dairy heifers prior to 1st mating) - SC only for cattle, IM only for pigs
50
Azithromycin - Kind of drug - Predominately used for?
- Macrolide - Rhodoccus equi (intracellular) - Predominately used for equine resp disorders esp foals Good intracellular penetration to alveolar macrophages, GIT side effects in adult horses
51
Clarithromycin - Kind of drug - Predominately used for?
- Macrolide - Rhodoccus equi (intracellular) - Predominately used for equine resp disorders esp foals Good intracellular penetration to alveolar macrophages, GIT side effects in adult horses
52
Chloramphenicol - gram, O2 use - resistance - drug distribution - dont use in what kind of species - systemic preparation?
- Other - Gram pos & neg aerobes and anaerobes - moderate resistance esp gram negs, but excellent anaerobic activity - excellent drug distribution - eg crosses the cornea - useful topical ophthalmic preparation - do NOT use in food producing species - systemic preparation pulled off the market!
53
Florenfenicol - registered for what - NOT to be used in what species - route of administration
- Other - Registered for resp dx, pink-eye and footrot - NOT to be used in dairy cows - IM
54
Clindamycin - targets what specific O2 requirement bacteria - gram and O2 use - suited for - toxicity - coverage against what protozoa
- Other - "antirobe' targets anaerobic infections - gram pos (some g neg) anaerobes (high!) - suited to abscesses, wounds, bone infections, periodontal dx - GIT toxicity if given to herbivores orally - important coverage against toxoplasma (protozoa)
55
Metronidazole - static or cidal? - excellent for what O2 requirement bacteria AND another kind of microbe - preperations
- Other - bactericidal - excellent anaerobic and anti-protozoal efficacy (*kills clostridium difficile) - different preparations - suspension, paste, IV infusion
56
Polymixin B - static or cidal? - O2 requirement bacteria? - good for coverage against what specific sp.? - systemic use?
Other - bactericidal - disrupts gram neg cell membs to alter cell permeability = lysis = bactericidal - primarily used for coverage against pseudomonas spp. (good bcs there's not many that does this!!) - not used systemically
57
Ecoli Gram? Oxygen usage?
gram neg facultative anaerobe
58
Staph pseudointermedius Gram? Oxygen usage?
gram pos facultative anaerobe
59
Clostridium sp Gram? Oxygen usage?
gram pos obligate aerobe
60
Pseudomonas aeruginosa Gram? Oxygen usage?
gram neg aerobe
61
Minimum inhibitory conc (MIC) vs Minimum bactericidal conc (MBC)
MIC = specific conc of an antibiotic that will inhibit the growth of a particular bacterium MBC = lowest conc where 99.9% of a culture is KILLED after 24 hrs incubation MBC >>> MIC = bacteriostatic (arrestor/inhibitor) MBC ~ MIC = bactericidal
62
Name 6 principle mechanisms of resistance
1. Intrinsic resistance eg. aminoglycosides and anaerobes 2. Decreased permeability to the drug in the cytoplasmic memb eg. some beta lactams and many gram -vs 3. Increased production of drug-destroying enzyme eg. beta lactamases 4. Target enzyme/protein is replaced by one with less affinity for the drug eg. altered penicillin binding protein in MRSA 5. Active extrusion of the drug by MDR P-glycoprotein pump eg. pseudomonas spp. 6. Biofilms provide a barrier to hosts immune system and many antibiotics eg. bladder wall, joints, IV catheters, ear canals
63
Classify the antibiotics by bactericidal/bacteriostatic and how they work

VET302! (10 decks)

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