Antimicrobial Stewardship Flashcards
What is an antimicrobial?
Any substance that destroys or inhibits the growth of microorganisms, especially pathogenic ones.
ex: Antiviral, Antifungal, Antibacterial.
What is a microorganism?
An organism of microscopic or ultramicroscopic size.
ex: Bacteria, Fungus, Virus, Amoeba.
When and where did Alexander Fleming discover penicillin?
1928 in his laboratory at St. Mary’s Hospital in London.
What is the story behind the discovery of penicillin?
Alexander Fleming left some petri dishes he had been working with on his lab bench. He went on vacation for a week and came back to find that Penicillium mold had grown in the petri dishes. Upon closer inspection, he discovered that rings of inhibition had formed around the Penicillium mold, meaning the mold was secreting something that inhibits bacterial growth.
What was discovered in 1945 by British scientists?
The beta-lactam ring.
What has happened with the invention of penicillin?
Antibiotic resistance.
What class of drugs was discovered in the 1930s?
Sulfonamides.
What is the function of sulfonamides?
To inhibit bacterial growth.
What were sulfonamides first used to treat?
Mastitis.
Sulfonamides become more effective when combined with what drug?
Diaminopyrimidines.
What is the most commonly used diaminopyrimidine used in combination with sulfonamides?
Trimethoprim.
What are the mechanisms of action that antibiotics may have?
- Metabolic pathway inhibition (Trimethoprim, Sulfonamides).
- Nucleic acid synthesis inhibitors (Fluoroquinolones).
- Protein synthesis inhibition (Tetracyclines, Aminoglycosides).
- Cell membrane depolarization (Lipopeptides).
- Cell wall synthesis inhibitors (Cephalosporins, Beta-lactams).
What are the 2 types of mechanisms of resistance that bacteria can have?
- Intrinsic.
- Acquired.
What is an intrinsic trait?
A universally shared trait by bacteria in a given species.
ex: Cell wall permeability, efflux pump.
What is an acquired trait?
A trait individual bacteria gain through horizontal gene transfer, plasmid gene transfer, and/or self-mutations.
What are some mechanisms of resistance that bacteria can have?
- Efflux of a drug.
- Drug inactivation.
- Limiting drug uptake.
- Modification of the drug target.
- Alteration of metabolic pathway.
What contributes to AMR?
- Increased antimicrobial usage-both animal and human.
- Early discontinuation of therapy.
- Sharing medications.
- Prescription of the incorrect antimicrobial.
- Poor hygiene and preventative medicine.
- Antimicrobials in the food supply.
What are the strategies to combat resistance?
- New innovations.
- Judicious antibiotic use.
- Regulation of antibiotic use.
- Combination products.
- Antibiotic additives.
- Disease prevention.
What strategies fall under disease prevention?
- Vaccination program.
- Vitamin and mineral supplementation as needed.
- Sanitation.
- Proper nutrition.
What falls under judicious antibiotic use?
- In-house diagnostic testing.
- Laboratory diagnostic testing.
- Evidence based medicine.
- Following the instructions on the label*.
*Veterinarians can use certain medications off-label.
What falls under combination products?
Sulfonamides + Trimethoprim.
What falls under antibiotic additive?
Amoxicillin + clavulanic acid.
What are the characteristics of Campylobacter jejuni?
- Gram negative.
- Helical shape.
- Zoonotic.
How is C.jejuni shed?
In the feces.
What are the reservoirs for C.jejuni?
- Dogs.
- Wildlife.
- Sheep.
- Cattle.
What is C.jejuni clone sheep abortion (SA)?
- The most common cause of abortions in sheep.
- Contributes to foodborne illness in people.
What class of drugs is C. jejuni resistant to in sheep?
Tetracyclines.
What are the characteristics of Staphylococcus spp. ?
- Gram positive.
- Cocci bacteria.
- Commensal, but opportunistic.
- Zoonotic, but interspecies transmission is not common.
*Associated with MRSA
What are MRSP skin infections common in?
- Dogs.
- Cats.
What is the challenging agent associated with mastitis?
Non-MRSA S. aureus.
What is Staph. aureus transmitted by?
Flies or within the milking parlor.
What does Staph. aureus cause on the mammary gland?
Micro-abscesses.
Why is Staph. aureus extremely challenging to cure?
It is shed intermittently, which is why good parlor hygiene is imperative.
What is vibrio spp. a pathogen of?
- Fish.
- Shellfish.
Where is vibrio spp. found?
Marine and brackish water, especially in May-August.
How is vibrio spp. transmitted?
- Humans ingesting raw fish or shellfish.
- Open wounds when swimming in marine or brackish environments.
What are the characteristics of salmonella spp.?
- Enteric organism, often asymptomatic.
- Gram negative.
- Rod-shaped.
How is salmonella spp. transmitted?
Foodborne via fecal oral transmission.
*Many animals are asymptomatic carriers.
What animal has MDR resistant salmonella spp. strains been found in?
Swine.
What are the characteristics of Pseudomonas aeruginosa?
- Gram negative.
- Rod bacteria.
- High level of intrinsic resistance.
Where is P. aeruginosa commonly found?
- Otitis externa in dogs.
- Chronic wounds in horses.
What are the characteristics of Pasteurellaceae?
- Gram negative.
- Coccobacillus.
- High morbidity.
- High mortality.
What are some strains of Pasteurellaceae?
- Histophilus somni.
- Manneheimia hemolytica.
- Pasteurella multocida.
What are two industries economically impacted by Pasteurellaceae?
- Dairy.
- Beef.
Where is pasteurellaceae found?
Upper respiratory tract, opportunistic.
*Causes severe pneumonia.
