Antiinfective drugs

Question 1

Types of microorganisms

Answer 1

Bacteria
Fungi
Viruses
Protozoa

Question 2

bacteriostatic antibiotics

Answer 2

Inhibit the growth of bacteria

Question 3

bactericidal antibiotics

Answer 3

Kill bacteria

Question 4

in vitro

Answer 4

artificial environment

Question 5

minimum inhibitory concentration

Answer 5

(MIC) is the lowest level of antibiotics that will stop the growth of the organism and gives an idea of how resistant the organism will be to the antibiotic.

Question 6

Aminoglycosides

Answer 6

antibiotic
bactericidal antibiotics that inhibit protein synthesis in bacteria.
These drugs are concentrated at high levels in the kidneys
these include the: Aminocyclitols, Gentamicin,

Question 7

Carbapenems

Answer 7

antibiotic
Usually bactericidal because they inhibit bacterial cell wall synthesis
Only human meds exist

Question 8

Cephalosporins

Answer 8

Bactericidal and interfere with bacterial cell-wall synthesis.
Generally excreted through the kidneys.
Many different kinds exist
Whether they work against gram-negative or gram-positive or both depends on the generation.
Examples- Cephalexin (1st generation, gram positive), Cefazolin (2nd generation, gram negative)

Question 9

Macrolides

Answer 9

Antibiotics primarily effective against gram-positive organisms.
many inhibit protein synthesis
Generally excreted through bile

Examples include erythromycin, tulathromycin, azithromycin, and tylosin.

can cause diarrhea and vomiting in small animals.
Can cause diarrhea in both ruminants and horses.

Question 10

lincosamides

Answer 10

Antibiotics
primarily effective against gram-positive organisms.
Also effective against anaerobes and toxoplasma parasites,
used to treat wounds, abscesses, and dental infections.
Lincosamides are distributed into most tissues and can cross the placenta.
Are partially metabolized in the liver.
Unchanged drug and metabolites are excreted in the urine, feces, and bile.

Bonus: Example clindamycin

Question 11

Polymyxin B and bacitracin

Answer 11

Used topically to treat skin and eye conditions.
Often combined with other drugs such as steroids or neomycin.

Question 12

Penicillin

Answer 12

bactericidal
effective against gram-positive microorganisms and tend to be excreted through the kidneys and urine.
mechanism of action is to bind to enzymes involved in cell-wall synthesis in bacteria.

ALL THIS IS BONUS —bacteria eventually burst and die, because their cell wall breaks down.
resistance to penicillins is through an enzyme called beta-lactamase (penicillinase).
The addition of a chemical such as clavulanic acid (which inhibits beta-lactamase)
–called potentiated penicillins.

examples amoxicillin and amoxicillin/clavulanate.

Question 13

Tetracyclines

Answer 13

are bacteriostatic
At very high doses, they’re bactericidal.
They have a wide spectrum of activity against gram-positive and gram-negative bacteria.
Most are excreted through the kidneys.
Examples- tetracycline and doxycycline

Bonus- If given to young can permanently stain the teeth of young animals (younger than six months)

Question 14

Quinolones and Fluoroquinolones

Answer 14

Bactericidal
It’s believed they prevents DNA supercoiling and DNA synthesis
They work against gram-negative bacilli and cocci
Eliminated through the production of bile by the liver and urine by the kidneys
- An example is enroflaxin (fluoroquinolones)

Bonus
Spread rapidly into the tissues and body fluids

Question 15

Quinolones and Fluoroquinolones contraindications

Answer 15

Should not be used in growing animals because they may cause cartilage abnormalities
Some fluoroquinolones are prohibited for use in cattle

Question 16

beta-lactamases

Answer 16

an enzyme that degrades beta-lactam antibiotics (penicillin) before they reach the bacteria’s cell wall.

Question 17

Sulfonamides

Answer 17

Bactericidal drugs with a broad spectrum of activity against gram-positive and gram-negative organisms.
also works against some protozoa
Kidney/liver

Question 18

Sulfonamides warnings

Answer 18

may also cause keratoconjunctivitis (inflammation of the eye and eyelid) and may be associated with autoimmune-mediated hemolytic anemia in small animals.

Question 19

anti-viruls

Answer 19

not commonly used
can be used for herpes eye infections in cats or Pacheco’s virus (herpesvirus infections in birds)
Interferon alfa has been used in cats to treat eye and skin diseases.

Question 20

Alcohol (as a cleaning agent)

Answer 20

kills bacteria, some viruses, and tuberculosis, although it doesn’t affect spores or fungi.
doesn’t penetrate organic material

Question 21

Formaldehyde

Answer 21

is effective against spores, bacteria, fungi, and viruses on inanimate objects.

Bonus-
Toxic to the skin and mucous membranes
Formaldehyde requires a long time to work and doesn’t work well with organic material.

Question 22

Chlorines and iodines

Answer 22

Kill Bacteria, Viruses, Fungi, Tuberculosis
Chlorines are used to clean floors and other hard surfaces. Iodines can be used to disinfect an animal’s skin before surgery, used against bacterial spores and also be used to sanitize food dishes and utensils.

Question 23

Zoonotic –

Answer 23

disease from animal can affect you,
include roundworms, hookworms, toxoplasmosis, and trichinella

Question 24

A disinfectant

Answer 24

is primarily for use on inanimate (not alive) objects
to kill microorganisms or inactivate viruses.

Question 25

hospital based infections

Answer 25

nosocomial

Question 26

Antiseptics

Answer 26

are for use on living tissues to kill
microorganisms

Question 27

Antimicrobials that inhibit cell wall synthesis -info and examples

Answer 27

Drugs that interfere with bacterial cell wall formation can kill or inhibit bacterial organisms only when the bacteria are growing or dividing.

• Penicillins
• Cephalosporins
• Bacitracin
• Vancomycin

Question 28

Damaging the bacterial cell membrane alters its barrier and allows antimicrobial drugs to enter and leave the cell. Give one example

Answer 28

• Polymixin B

Question 29

Antimicrobials that inhibit protein synthesis - info and examples

Answer 29

Antimicrobial drugs target bacterial protein synthesis by binding to the ribosomes and disrupting the bacteria’s metabolism leading to inhibition of growth or death.

• Aminoglycosides
• Tetracyclines
• Macrolides
• Lincosamides
• Chloramphenicol

Question 30

Antimicrobials that Inhibit nucleic acid synthesis -info and examples

Answer 30

Antimicrobial drugs bind to components involved with DNA and RNA synthesis and interfere with division and survival.
* Fluoroquinolones
* Metronidazole
* Rifampin

Question 31

Antimicrobials that inhibit metabolic processes -info and examples

Answer 31

These drugs interfere with cellular processes (block or bind to bacterial enzymes) essential for the bacteria’s survival.
* Sulfonamides

Question 32

Gram-positive bacteria

Answer 32

A type of bacteria that have a thick cell wall.
This cell wall helps protect the bacteria from antibiotics and other substances that might damage them.
Examples- staph and strep

Question 33

Gram-negative bacteria

Answer 33

Gram-negative bacteria have an outer membrane that protects them against certain antibiotics, such as penicillin. When disrupted, this membrane releases toxic substances called endotoxins
Examples- Pseudomonas and e-coli