40 Questions
What term is defined as the time that must elapse between the last administration of a veterinary medicine and the slaughter or production of food from that animal?
Withdrawal period
Which type of resistance is acquired by bacteria through processes like conjugation, transduction, and transformation?
Acquired resistance
What is the main mechanism behind innate resistance in bacteria?
Genomic property
What does AMR stand for in the context of drug therapy and antibiotic use?
Antimicrobial Resistance
Which process involves bacteria passing acquired resistance to other bacteria?
Horizontal gene transfer
What can lead to an increase in resistant bacteria even during treatment with antimicrobials?
Error-prone polymerases resulting in resistant mutations
How do antimicrobials contribute to the spread of antibiotic resistance genes (ARGs) between bacteria?
Activation of DNA repair mechanisms
What is one of the consequences of stress-induced activation of mutagenesis response in bacteria?
Increased generation of resistant mutations
Under supra-MIC conditions, what happens to the mutation rates as compared to original conditions?
Increase in mutation rates
Why do various components of the environment act as a depository for the accumulation, formation, and spread of antibiotic resistance?
As a result of horizontal gene transfer mechanisms
How do antibacterials interfere with bacterial cell life or growth?
By interacting with a vital structure or blocking a metabolic pathway
Which of the following is NOT a common administration route for drug therapy?
Intercostal
What is the primary purpose of antimicrobial agents?
Preventing microbial multiplication
Which principle is referred to as ADME in drug therapy?
Absorption, Distribution, Metabolism, and Excretion
What is a key property of a drug related to maintaining concentrations at the site of action without causing toxicity?
Selectivity
What is the primary consideration to prevent the emergence of antimicrobial resistance?
Selecting antimicrobials based on the wild-type population susceptibility
Which factor is crucial for the effectiveness of drug therapy in killing pathogens?
Concentration and time of exposure within the bacterium
In drug therapy, which killing pattern is characterized by antimicrobial effect increasing with a greater drug concentration?
Concentration-dependent killing pattern
What does the hybrid pattern in drug therapy refer to?
Simultaneous time-dependent and concentration-dependent killing effects
Which factor determines the effectiveness of antibiotics in killing pathogens according to the text?
Duration of pathogen exposure to the antibiotic
What does the area under the serum concentration curve (AUC) after a dose of antibiotic measure?
The height of the antibiotic concentration and the duration it remains above the target MIC
How are breakpoints for defining bacterial susceptibility set?
By considering microbiological, pharmacological, and clinical parameters
What does the term 'Intermediate' mean when categorizing bacterial strains?
Uncertain probability of successful treatment
What is the Acceptable Daily Intake (ADI) defined as?
The daily intake of a substance that appears to be without adverse effects over a human lifetime
What is the purpose of a withdrawal period in food-producing animals?
To minimize the risk of antibiotic residues in food products
What does PHARMACOKINETICS (PK) primarily study?
Drug absorption, distribution, metabolism, and excretion
Which of the following is NOT a component of the ADME principle in pharmacokinetics?
Therapeutic effects
What is the minimum inhibitory concentration (MIC) defined as?
The lowest concentration of antibiotic that completely inhibits growth
Potency of a drug is determined by:
The concentration at which 50% of the maximum effect is achieved
In what way do PK/PD relationships influence drug therapy?
Representing an exposure/response relationship
Which type of antibiotic requires active growth of bacteria to be effective?
Bactericidal
What does the Minimum Bactericidal Concentration (MBC) measure in relation to antibiotics?
The lowest concentration at which bacteria are killed
Which type of antimicrobial acts against a limited group of bacteria?
Narrow-spectrum
What is the main difference between bacteriostatic and bactericidal antibiotics?
Effect on bacterial growth
What do broad-spectrum antimicrobials act against?
A large group of bacteria
In the disk diffusion test, what do the diameters of inhibition zones indicate?
Susceptibility or resistance to the antibiotic
What does the term 'bacteriostatic' mean in relation to antibiotics?
Inhibits bacterial growth
'Spectrum of activity' in drug therapy refers to the antibiotics' ability to act against:
A large group of bacteria
'Minimum Bactericidal Concentration' (MBC) is defined as the lowest concentration at which:
'Bacteria are killed'
'BacteriCIDAL agents' differ from 'BacterioSTATIC agents' in that they:
Require active growth for effectiveness
Study Notes
Drug Therapy Principles
- Definition of Drug Therapy: Any medical treatment that utilizes one or more drugs to provide symptomatic relief, treat the underlying condition, or act as a prevention for diseases.
Factors Affecting Drug Choice
- Factors to Consider: Selectivity, Concentrations, Time
- Selectivity: Target vs non-desired targets
- Concentrations: Sufficient at the site of action vs toxicity
- Time: Maintenance vs depletion
Antibiotics/Antimicrobials
- Definition: Any substance of natural, semisynthetic, or synthetic origin that either kills microbes or prevents their multiplication, reducing their pathogenic effect.
-
Mechanisms of Action:
- Destroying bacterial cell membranes
- Preventing bacterial cell wall synthesis
- Disrupting bacterial metabolic pathways
- Interfering with bacterial DNA synthesis
Administration Routes
- Systemic Routes: Enteral, Parenteral, Inhalation
- Local Routes: Topical, Transdermal, Intramammary, Rectal, Intramuscular, Subcutaneous
Antimicrobial Resistance (AMR)
- Definition: The ability of microorganisms to resist the effects of antimicrobial agents.
-
Mechanisms of Resistance:
- Innate (natural) resistance
- Acquired resistance (mutation or horizontal gene transfer)
-
Factors Contributing to AMR:
- Antibiotic Stress Response
- Mutation rates increased under supra-MIC conditions
- Horizontal gene transfer
- Environmental reservoirs of antibiotic resistance genes
Pharmacokinetics (PK) and Pharmacodynamics (PD)
- PK: Study of what the body does to the drug (absorption, distribution, metabolism, and excretion)
- PD: Study of what the drug does to the body and the target
- PK/PD together: Exposure/response relationship
In Vitro Evidence
- Minimum Inhibitory Concentration (MIC): Lowest concentration of antibiotic that completely inhibits growth of the specific organism being tested
- Minimum Bactericidal Concentration (MBC): Lowest concentration of antibiotic that kills bacteria
- Disk Diffusion Test: Reference susceptibility test evaluating the diameters of inhibition zones around antibiotic-containing disks
Spectrum of Activity
- Narrow-Spectrum Antimicrobials: Act against a limited group of bacteria
- Broad-Spectrum Antimicrobials: Act against a large group of bacteria
Test your knowledge on how antimicrobials can lead to the development of antimicrobial resistance (AMR) in bacteria during drug therapy. Learn about mutagenesis due to stress, the SOS response, error-prone polymerases, and increased mutation rates.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
