Difficulty: Medium
Correct Answer: Cephalosporin C
Explanation:
Introduction / Context:
Cephalosporins are beta-lactam antibiotics with a broader Gram-negative spectrum than many penicillins. This question asks which cephalosporin, among the options, is known to be more active than penicillin against Salmonella species.
Given Data / Assumptions:
Concept / Approach:
Cephalosporin C is a natural cephalosporin with better inherent activity against many Gram-negative rods than classic penicillins. While cephalosporin N is penicillin-like and historically considered closer to a penicillin derivative, cephalosporin C exhibits the broader Gram-negative profile aligning with Salmonella susceptibility compared to early penicillins.
Step-by-Step Solution:
Recognize Salmonella as Gram-negative enteric bacteria.Recall that cephalosporin C shows improved Gram-negative activity over early penicillins.Note that cephalosporin N is less distinct from penicillins in activity spectrum.Select cephalosporin C as the better option against Salmonella.
Verification / Alternative check:
Historical antimicrobial spectra summaries place cephalosporin C ahead of baseline penicillin against many enteric Gram-negatives in vitro, consistent with the question’s framing.
Why Other Options Are Wrong:
Cephalosporin N: more penicillin-like; not superior to penicillin across Salmonella.Synnematin: not a standard cephalosporin used for Salmonella and not superior to penicillin in this context.Both (a) and (c): includes incorrect elements.
Common Pitfalls:
Assuming all cephalosporins outperform penicillins on every Gram-negative organism; activity varies by agent and species.
Final Answer:
Cephalosporin C
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