Before the 1950s blank was used to blank but during the 1950s blank and other antibiotics were discovered that could treat the new resistance form

Answer 1

Before the 1950s, penicillin was used to effectively treat bacterial infections, but during the 1950s, methicillin and other antibiotics were discovered that could treat the new resistance forms, such as methicillin-resistant Staphylococcus aureus (MRSA).