Consider a population of Clostridium difficile living in the human gut. Regular ingestion of an antibiotic is a selective process on the gut ecosystem. Which of the following events could be considered adaptive mutations for C. difficile in this environment? A. Acquisition of a plasmid with a gene encoding an enzyme to inactivate the antibiotic B. Deletion of the gene encoding a restriction endonuclease C. Duplication of the gene encoding flagellin D. Point mutation changing a single amino acid in a membrane transporter

Acquisition of a plasmid with a gene encoding an enzyme to inactivate the antibiotic

Explanation:

Clostridium difficile is a Gram-positive gastroimtestinal bacteria that forms spore it cause a range of diseases like antibiotic-associated diarrhea (AAD).

C. difficile genome harbors a variety of resistance genes that makes it resistance to different classes of antibiotics. Analysis conducted on C. difficile 630 genome identified genes encoding β-lactamase-like proteins and penicillin-binding proteins (PBPs) as one that mediate the resistance to the β-lactam antibiotics such as penicillin and cephalosporins this is done by an enzymes that unlocks the drug active site making the bacteria resistance to it.