785884
Description
Flashcards by sophietevans, updated more than 1 year ago
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Created by sophietevans
over 10 years ago
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| Question | Answer |
| Which group of antibiotics do cephalosporins have the same mechanism of action as? | Penicillins, as they are a large group of natural and semi-synthetic β-lactam drugs too. |
| How do cephalosporins inhibit bacterial cell wall synthesis? | By inhibiting transpeptidases, preventing N-acetylmuramic acid cross-linking, resulting in cell lysis due to osmotic pressure. Peptidoglycan is composed of alternating N-acetylglucosamine and N-acetylmuramic acid residues, and the N-acetylmuramic acid residues cross-link with short peptide side chains. Cephalosporins form covalent bonds with transpeptidases which catalyse the cross-link formation, so the cell wall cannot resist the high osmotic pressure and the bacterial cell lyses. |
| Cephalosporins are broad-spectrum. What does this mean? | They can be used against a wide range of both Gram-positive and Gram-negative bacteria. |
| List some of the conditions that cephalosporins can be used to treat. | Septicaemia, meningitis, urinary and biliary tract infections, peritonitis, and some STIs such as gonorrhea (caused by Neisseria gonorrheae), as well as nosocomial infections such as Pseudomonas aeruginosa, Staphylococcus aureus, and Streptococcus pneumoniae. |
| Is there wide-spread resistance to cephalosporins? | No. Although resistance to cephalosporins does occur, such as its low affinity for methicillin-resistant Staphylococcus aureus which has a modified transpeptidase enzyme, many cephalosporins are stable to β-lactamases which render penicillins ineffective, so their use is maintained. |
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