Podcast
Questions and Answers
What is the source of the first members of the cephalosporin class?
What is the source of the first members of the cephalosporin class?
- Bacteria
- Penicillium mold
- Cephalosporium acremonium (correct)
- Fungus Florey
Which of the following bacteria produces peptidoglycan and is affected by natural penicillins?
Which of the following bacteria produces peptidoglycan and is affected by natural penicillins?
- Chlamydia spp.
- Streptococcus pneumoniae (correct)
- Leptospira spp.
- Mycoplasma spp.
How are cephalosporins categorized?
How are cephalosporins categorized?
- By generation (correct)
- By their spectra of activity
- By their chemical structure
- By their side chains
What is the mechanism of resistance of some bacteria to natural penicillins?
What is the mechanism of resistance of some bacteria to natural penicillins?
What is the nucleus of a cephalosporin composed of?
What is the nucleus of a cephalosporin composed of?
Which of the following bacteria is susceptible to natural penicillins?
Which of the following bacteria is susceptible to natural penicillins?
What is the characteristic of cephalosporins within the β-lactam group?
What is the characteristic of cephalosporins within the β-lactam group?
What is the characteristic of antistaphylococcal penicillins?
What is the characteristic of antistaphylococcal penicillins?
What is the common feature of agents in each generation of cephalosporins?
What is the common feature of agents in each generation of cephalosporins?
What is the term used to describe the categorization of cephalosporins?
What is the term used to describe the categorization of cephalosporins?
Which of the following bacteria is resistant to antistaphylococcal penicillins?
Which of the following bacteria is resistant to antistaphylococcal penicillins?
What is the significance of the generation categorization of cephalosporins?
What is the significance of the generation categorization of cephalosporins?
What is the mechanism of action of natural penicillins?
What is the mechanism of action of natural penicillins?
Which of the following bacteria produces β-lactamases that degrade natural penicillins?
Which of the following bacteria produces β-lactamases that degrade natural penicillins?
What is the benefit of understanding the properties of cephalosporins?
What is the benefit of understanding the properties of cephalosporins?
What is the limitation of natural penicillins?
What is the limitation of natural penicillins?
Which type of penicillins is useful in treating infections caused by Staphylococcus aureus?
Which type of penicillins is useful in treating infections caused by Staphylococcus aureus?
What is the primary mechanism of action of penicillins?
What is the primary mechanism of action of penicillins?
What is the effect of adding a β-lactamase inhibitor to an aminopenicillin?
What is the effect of adding a β-lactamase inhibitor to an aminopenicillin?
What is the primary difference between natural penicillins and aminopenicillins?
What is the primary difference between natural penicillins and aminopenicillins?
Which type of bacteria are natural penicillins most active against?
Which type of bacteria are natural penicillins most active against?
What is the primary advantage of extended-spectrum penicillins over aminopenicillins?
What is the primary advantage of extended-spectrum penicillins over aminopenicillins?
Which of the following is a characteristic of extended-spectrum penicillins?
Which of the following is a characteristic of extended-spectrum penicillins?
What is the effect of using extended-spectrum penicillins in combination with β-lactamase inhibitors?
What is the effect of using extended-spectrum penicillins in combination with β-lactamase inhibitors?
Study Notes
Penicillins
- Act by binding to PBPs, which are bacterial enzymes that function to assemble peptidoglycan.
- Natural penicillins have moderate activity against aerobic gram-positive bacteria and anaerobic bacteria, but poor activity against aerobic gram-negative bacteria and most atypical bacteria.
- Limitations of natural penicillins include:
- Producing penicillinases that degrade natural penicillins (e.g., some anaerobes, such as Bacteroides fragilis).
- Some bacteria produce PBPs that do not bind natural penicillins with high affinity (e.g., some strains of Streptococcus pneumoniae).
- Some bacteria do not make peptidoglycan and are not affected by natural penicillins (e.g., Mycoplasma and Chlamydia spp.).
Antistaphylococcal Penicillins
- Have bulky residues on their R side chains that prevent binding by staphylococcal β-lactamases.
- Useful in treating infections caused by S. aureus and Staphylococcus epidermidis, but not effective against methicillin-resistant S. aureus (MRSA) and methicillin-resistant S. epidermidis (MRSE).
Extended-Spectrum Penicillins
- Active against even more enteric gram-negative rods and importantly, Pseudomonas aeruginosa.
- Addition of a β-lactamase inhibitor to an extended-spectrum penicillin extends its activity to include most enteric gram-negative bacilli.
Cephalosporins
- Constitute a large extended family of antibiotics within the β-lactam group.
- Can be categorized by "generation", with each generation having similar spectra of activity.
- Each cephalosporin is composed of a nucleus with two side chains.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
This quiz covers various bacteria species, their characteristics, and how they interact with antibiotics. Topics include Actinomyces israelii, Spirochetes, Treponema pallidum, Leptospira spp., and Bacteroides fragilis.
