Question

in 2015, doctors in the united states identified a strain of escherichia coli (e. coli) that carried a gene called mcr - 1, which makes the bacteria resistant to colistin, an antibiotic considered a \last resort\ when other drugs fail. the patient carrying this strain had not traveled abroad, showing that the resistant bacteria were already spreading within u.s. communities. colistin resistance is especially concerning because colistin is one of the few antibiotics effective against certain multi - drug resistant infections. scientists warn that if genes like mcr - 1 spread widely, we could enter a \post - antibiotic era\ where even common infections are much harder to treat. why is resistance to colistin especially alarming? colistin is a last - resort antibiotic for multi - drug resistant infections colistin is an inexpensive drug colistin is used only in animals colistin is no longer prescribed in the u.s.

Explanation:

The text states that colistin is a "last - resort" antibiotic for multi - drug resistant infections. Resistance to it is alarming because it's one of the few effective drugs against such infections.

Answer:

Colistin is a last - resort antibiotic for multi - drug resistant infections