Difficulty: Medium

Average Score: 67%

A population of Pseudomonas aeruginosa is exposed to successive, short rounds of ampicillin and chloramphenicol. What will happen to the population?

Rationale

The population will become resistant to chloramphenicol.

Exposure to successive rounds of antibiotics like chloramphenicol can lead to selective pressure on Pseudomonas aeruginosa, resulting in the development of resistance mechanisms against the drug. Over time, the bacteria can acquire mutations or gain resistance genes, allowing them to survive despite the presence of the antibiotic.

A (The population will become resistant to chloramphenicol.) CORRECT

With repeated exposure to chloramphenicol, the bacteria face selective pressure that favors those with resistance traits. This can lead to genetic changes such as mutations in target sites or the acquisition of resistance genes, ultimately resulting in a resistant population capable of surviving future chloramphenicol exposure.

B (The population will die.) YOUR ANSWER

While some bacteria may initially be killed by chloramphenicol, the population as a whole is likely to survive if resistant individuals emerge. Not all members of the population will succumb to the antibiotic, particularly if they possess or develop resistance mechanisms, allowing the population to persist and potentially grow.

C (The population will become resistant to ampicillin and chloramphenicol.) YOUR ANSWER

This choice suggests that the population would develop resistance to both antibiotics; however, the question specifies exposure to chloramphenicol. Resistance to ampicillin would not necessarily develop unless the bacteria were exposed to it directly, as resistance mechanisms are often specific to the antibiotic used.

D (The population will become resistant to ampicillin.) YOUR ANSWER

Similar to choice C, the resistance to ampicillin would not occur as a direct result of exposure solely to chloramphenicol. Resistance mechanisms often require specific selection pressure from the antibiotic in question, and without exposure to ampicillin, there is no basis for the development of resistance to it.

Conclusion

In conclusion, repeated exposure to chloramphenicol creates an environment where resistant strains of Pseudomonas aeruginosa can emerge, while the overall population may not die out. This highlights the importance of understanding antibiotic resistance mechanisms, which can have significant implications for treatment efficacy in clinical settings.

Related Questions

View all