What term describes bacteria that are not killed by antibiotics?

• A. Antibiotic Susceptibility
• B. Antibiotic Resistance
• C. Tolerance
• D. Virulence

Answer: (B)

The main idea here is how some bacteria survive even when an antibiotic is present. That describes antibiotic resistance: genetic changes or acquired genes that let a bacterium continue to grow in the presence of an antibiotic that would normally stop it. Resistance can arise through mechanisms like altering the drug’s target, destroying or inactivating the drug, reducing drug uptake, or pumping the drug out of the cell. It can be spread between bacteria, making resistant strains a major public health concern.

Antibiotic susceptibility means the organism is inhibited or killed by the antibiotic, which is the opposite. Tolerance means bacteria can survive exposure for a longer time without being killed quickly, but they aren’t necessarily able to grow in that antibiotic’s presence or pass on resistance. Virulence relates to how harmful a bacterium is, not how it responds to antibiotics.