Question

Despite some evidence that antibiotic resistance can confer a fitness disadvantage to bacteria in nonantibiotic environments as compared to susceptible strains, research has also documented that ________.

1) compensatory evolution by way of mutation events in other genes may very well make antibiotic resistant strains as fit, or even more fit, than sensitive strains

2) an energy balance trade-off outweighs the advantages that antibiotic sensitive strains have otherwise

3) lstrains sensitive to antibiotics will readily and spontaneously mutate at will to achieve antibiotic resistance, even in the absence of antibiotics

4) None of the above.

Answer 1

Compensatory evolution may make antibiotic-resistant bacteria as fit or fitter than sensitive strains. Antibiotic resistance evolves through natural selection acting on pre-existing genetic variations, leading to greater frequency of resistant genes in bacterial populations and a concern for public health.

Step-by-step explanation:

Research has documented that compensatory evolution by way of mutation events in other genes may very well make antibiotic-resistant strains as fit, or even more fit, than sensitive strains. This occurs because while antibiotic resistance may initially confer a fitness disadvantage to bacteria in nonantibiotic environments, mutations in other genes can offset this disadvantage. The excessive use of antibiotics selects for resistant forms of bacteria, leading to the spread and persistence of antibiotic-resistant genes in the bacterial population.

It's crucial to recognize that the antibiotic resistance is a form of evolution that relies on genetic variation already present within bacterial populations, rather than mutations arising as an immediate response to antibiotics application. Over time, the exposure to antibiotics results in a natural selection process where resistant bacteria are more likely to survive and reproduce, outcompeting the non-resistant varieties. This phenomenon illustrates why the emergence of antibiotic-resistant bacteria is a significant concern for public health.