Question

When first used in medicine in the 1940s, penicillin was uniformly effective in killing the bacterium staphylococcus aureus. today, ____________________ has led to an increase in antibiotic-resistant alleles, and humans are increasingly at risk from untreatable staphylococcus aureus infections. a. molecular genetics b. natural selection in staphylococcus aureus populations c. natural selection in human populations d. uncleanliness in hospitals e. the substitution of methicillin for penicillin?

Answer 1

When first used in medicine in the 1940s, penicillin was uniformly effective in killing the bacterium staphylococcus aureus. today, natural selection in staphylococcus aureus populations has led to an increase in antibiotic-resistant alleles.
Staphylococcus aureus is a Gram-positive, round-shaped bacterium and common cause of skin infections.
Antibiotic resistant strains of S. aureus such as methicillin-resistant S. aureus (MRSA) is problem in medicine.