Podcast Beta
Questions and Answers
Which type of antibiotic is Doripenem?
How is the mechanism of action of antibiotics best categorized?
Based on the structure of the bacteria
Anti-pseudomonal penicillin includes Piperacillin-tazobactam.
True
Which antibiotic is considered the last resort?
Signup and view all the answers
Which category of antibiotics kills the bacteria?
Signup and view all the answers
Fluoroquinolones are especially used for ________.
Signup and view all the answers
Beta-Lactam antibiotics inhibit the synthesis of (blank)
Signup and view all the answers
Match the following antibiotics with their types:
Signup and view all the answers
What are the mechanisms of antibiotic resistance discussed in the content?
Signup and view all the answers
Why is reducing permeability one of the mechanisms of antibiotic resistance?
Signup and view all the answers
Enzymes can inactivate antibiotics, rendering them ineffective. (True/False)
Signup and view all the answers
Match the antibiotic with the correct category it belongs to:
Signup and view all the answers
Which drugs can be used for MSSA + Strep A infections orally?
Signup and view all the answers
Which antibiotic inhibits RNA polymerase?
Signup and view all the answers
DNA gyrase inhibitors inhibit the ligating portion of the DNA gyrase while increasing the cutting portion, which fragments the DNA into pieces. One example of DNA gyrase inhibitor antibiotics is ___________.
Signup and view all the answers
Which drug is a common empiric antibiotic for Pyelonephritis?
Signup and view all the answers
Trimethoprim inhibits dihydrofolate reductase.
Signup and view all the answers
What is the most common pathogen for Acute Cystitis?
Signup and view all the answers
What is the mechanism of action of Polymyxin?
Signup and view all the answers
Neisseria gonorrhoeae can spread to joints.
Signup and view all the answers
Match the pathogens with the appropriate antibiotics for Community-Acquired Meningitis:
Signup and view all the answers
What is the mechanism of action of Levofloxacin?
Signup and view all the answers
What are the three mechanisms by which DNA/RNA material can bring opportunities for bacteria when it gets destroyed?
Signup and view all the answers
What are the methods of horizontal gene transfer in bacteria?
Signup and view all the answers
Overprescribing antibiotics in hospitals does not contribute to the risk of antibiotic resistance, True or False?
Signup and view all the answers
In conjugation, bacteria connect via a ____.
Signup and view all the answers
Match the mechanisms of resistance to antibiotics with their descriptions:
Signup and view all the answers
Why do we get a sputum culture for a patient with an infection like pneumonia?
Signup and view all the answers
What is the purpose of getting a urinary culture for a patient with a UTI?
Signup and view all the answers
What method is used to determine the minimum inhibitory concentration (MIC) of antibiotics?
Signup and view all the answers
Match the antibiotics with their categories:
Signup and view all the answers
Susceptibility testing helps in determining which antibiotics the bacteria are resistant to.
Signup and view all the answers
The following drug can be used in both community and hospital-acquired meningitis:
Signup and view all the answers
What is the mechanism of action of Vancomycin?
Signup and view all the answers
Which drug is NOT used for pseudomonas infections?
Signup and view all the answers
Which drug will you give to treat a patient's infection if the antibiotic susceptibility testing shows resistance to the commonly used drug for the particular organism?
Signup and view all the answers
A triad of rashes, muscle spasms, and hypotension are side effects of the following:
Signup and view all the answers
Which of the following is NOT an anti-Pseudomonal antibiotic?
Signup and view all the answers
Which of the following can be used conveniently in methicillin-susceptible S. aureus infection of the skin?
Signup and view all the answers
Which of the following can be used in a pregnant patient with acute cystitis?
Signup and view all the answers
Study Notes
Introduction & Mechanism of Action
- Antibiotics can be categorized based on the structure of the bacteria they target
- Antibiotics can be either bactericidal (killing the bacteria) or bacteriostatic (inhibiting the growth of the bacteria)
Mechanisms of Action
-
Cell Wall Synthesis
- Inhibits the enzymes that synthesize cell wall synthesis
- Limits the wall synthesis, preventing bacteria from dividing properly
- Bacteria become susceptible to materials leaking in or out of the cell, introducing opportunity for bacterial death
-
Cell Membrane Integrity
- Creates efflux pumps in the cell membrane, increasing permeability and risk of cell lysis
- Examples: Daptomycin and Polymyxin
-
Folic Acid Pathway
- Inhibits nucleotide synthesis of bacteria
- Examples: Sulfamethoxazole (SMX) and Trimethoprim (TMP)
-
DNA Integrity
- Increases the formation of reactive oxygen species (ROS), causing damage to DNA, RNA, and/or proteins
- Examples: Metronidazole and Nitrofurantoin
-
Messenger RNA Synthesis
- Inhibits RNA polymerase
- Examples: Rifampin (used in tuberculosis)
-
DNA Gyrase Function
- Inhibits DNA gyrase, which helps maintain DNA topology
- Examples: Fluoroquinolones (Ciprofloxacin, Levofloxacin, Gemifloxacin, Moxifloxacin)
-
Protein Synthesis Inhibitors
- 50S Ribosomal Subunit: Macrolides (Azithromycin, Erythromycin, Clarithromycin), Clindamycin, and Chloramphenicol
- 30S Ribosomal Subunit: Aminoglycosides (Tobramycin, Amikacin, Gentamicin) and Tetracycline (Doxycycline, Tetracycline)
Bacterial Coverage
-
Gram Positive Coverage
- Examples: Beta-Lactams (Penicillin, Cephalosporin, Carbapenem, Monobactam) and Vancomycin
-
Gram Negative Coverage
- Examples: Beta-Lactams (Penicillin, Cephalosporin, Carbapenem, Monobactam) and Fosfomycin
-
Anaerobic Coverage
- Examples: Metronidazole and Nitrofurantoin
-
Atypical Coverage
- Examples: Azithromycin and Rifampin (used in tuberculosis)
Empiric Antibiotics for Common Infections
-
Pulmonary
- Examples: Cephalosporin and Macrolides
-
Gastrointestinal
- Examples: Cephalosporin and Fluoroquinolones
-
Skin and Soft Tissues
- Examples: Cephalosporin and Beta-Lactams
-
Urinary Tract
- Examples: Fluoroquinolones and Cephalosporin
-
Bone and Joint
- Examples: Fluoroquinolones and Cephalosporin
-
CNS
- Examples: Beta-Lactams and Cephalosporin
-
Bloodstream
- Examples: Beta-Lactams and Cephalosporin### Bacterial Coverage
Gram Positive Coverage
- Methicillin Sensitive Staphylococcus aureus (MSSA):
- Treated with anti-staphylococcal penicillin (nafcillin, oxacillin, dicloxacillin)
- 1st generation cephalosporins (cephalexin, cefazolin)
- Fluoroquinolones
- Methicillin Resistant Staphylococcus aureus (MRSA):
- Treated with 5th generation cephalosporin (ceftaroline)
- Vancomycin
- Trimethoprim-sulfamethoxazole
- Clindamycin
- Linezolid
- Doxycycline
- Daptomycin
- Streptococcus pneumoniae:
- Treated with penicillin
- Aminopenicillins
- 3rd generation cephalosporins (ceftriaxone)
- Fluoroquinolones (moxifloxacin, levofloxacin)
- Macrolides
- Clindamycin
- Streptococcus (Group A & B):
- Treated with anti-staphylococcal penicillin (nafcillin, oxacillin, dicloxacillin)
- 1st generation cephalosporins (cephalexin, cefazolin)
Gram Negative Coverage
- HENS-PEcK organisms:
- Hemophilus influenzae
- Enterobacter
- Neisseria gonorrhoeae and meningitidis
- Serratia
- Proteus
- Escherichia coli
- Klebsiella
- Treated with aminopenicillins (ampicillin)
- Anti-pseudomonal penicillin (piperacillin-tazobactam)
- 1st generation cephalosporins (cephalexin, cefazolin)
- 2nd, 3rd, 4th generation cephalosporins
- Carbapenems (doripenem, imipenem, meropenem, ertapenem)
- Monobactams
- Fluoroquinolones
- Aminoglycosides
- Extended spectrum beta lactamase bacteria (ESBL):
- Enterobacteriaceae
- Treated with carbapenems (doripenem, imipenem, meropenem, ertapenem)
- 3rd generation cephalosporin + beta lactamase inhibitor (ceftazidime+avibactam)
Anaerobic Coverage
- CBPFA organisms:
- Clostridium
- Bacteroides
- Peptostreptococcus
- Fusobacterium
- Actinomyces
- Treated with clindamycin
- Metronidazole
- Carbapenems
- Anti-pseudomonal penicillin (piperacillin-tazobactam)
- Fluoroquinolones
- MCL organisms:
- Mycoplasma
- Chlamydia
- Legionella
- Treated with fluoroquinolones
- Macrolides
- Chloramphenicol
- Doxycycline
Empiric Antibiotics for Common Infections
-
Pulmonary:
- Community-Acquired Pneumonia (CAP):
- Fluoroquinolones (respiratory)
- Beta-lactam (ceftriaxone) + macrolide or doxycycline
- Hospital-Acquired Pneumonia (HAP):
- Vancomycin
- Antipseudomonal penicillin (piperacillin-tazobactam)
- Ceftazidime, cefepime, or an aminoglycoside
- Community-Acquired Pneumonia (CAP):
-
Gastrointestinal:
- Gram-Negatives and Anaerobes:
- Carbapenems
- Antipseudomonal penicillins (piperacillin-tazobactam)
- Metronidazole + fluoroquinolone (ciprofloxacin)
- Metronidazole + ceftriaxone
- Metronidazole + cefepime
- Gram-Negatives and Anaerobes:
-
Skin and Soft Tissues:
- MSSA + Strep A:
- PO: dicloxacillin or cephalexin
- IV: nafcillin or oxacillin or cefazolin
- MRSA + Strep A:
- PO: TMP-SMX, doxycycline, or clindamycin
- IV: vancomycin
- MSSA + Strep A:
-
Urinary Tract:
- Pyelonephritis:
- Ceftriaxone
- Fluoroquinolone (ciprofloxacin)
- Aminopenicillin (ampicillin)
- Complicated UTI:
- Vancomycin
- Antipseudomonal penicillin (piperacillin-tazobactam)
- Ceftazidime, cefepime, or an aminoglycoside
- Pyelonephritis:
-
Bone and Joint:
- Septic arthritis, osteomyelitis:
- Vancomycin
- Ceftriaxone
- Cefepime, ceftazidime, or an aminoglycoside
- Septic arthritis, osteomyelitis:
-
CNS:
- Community-Acquired Meningitis (CAM):
- Vancomycin
- 3rd generation cephalosporin (ceftriaxone)### Empiric Antibiotics for Meningitis
- Community-Acquired Meningitis (CAM):
-
Ceftriaxone: good CNS penetration, covers H. catarrhalis and N. meningitidis
-
Ampicillin: consider for Listeria, especially in older patients (> 60 y/o), immunocompromised patients, and babies
-
Hospital-Acquired Meningitis (HAM): consider MRSA and Pseudomonas, use Vancomycin and Cefepime respectively
Empiric Antibiotics for Bloodstream Infections
- Central Line Bloodstream Infection (CLABSI): consider MRSA, use Vancomycin and +/- Pip-Tazo
- Sepsis: consider Vancomycin and Pip-Tazo for Gram-positives and Gram-negatives respectively
Antibiotics Pharmacology
- Adverse effects:
- Neurotoxicity: seizures, myoclonus, encephalopathy, serotonin syndrome
- Pancytopenia: hemolytic anemia, especially with beta-lactams
- Teratogenicity: avoid during pregnancy, especially with TMP-SMX
- Hyperkalemia: TMP-SMX
Mechanisms of Antibiotic Resistance
- Reduced permeability:
- Vancomycin
- Aminoglycosides
- Tetracyclines
- Beta-lactams
- Increased efflux:
- Fluoroquinolones
- Aminoglycosides
- Tetracyclines
- Macrolides
- Decreased target binding:
- Fluoroquinolones
- Aminoglycosides
- Tetracyclines
- Beta-lactams
- Macrolides
- Linezolid
- Trimethoprim-Sulfamethoxazole
- Increased inactivating enzymes:
- Beta-lactams: beta-lactamase, carbapenemase
- Aminoglycosides: phosphorylation, acetylation, methylation reactions
- Macrolides
Transmission of Antibiotic Resistance
- Bacteria can pass on resistance mechanisms to other bacteria through:
- Reduced permeability
- Increased efflux
- Decreased target binding
- Increased inactivating enzymes
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Test your knowledge on antibiotics, their uses, and effects in medical treatment. Learn about different types of antibiotics and their applications.