3.33

3.33 understand how resistance to antibiotics can increase in bacterial populations

Staphylococcus aureus treated by methicillin (antibiotic)

At first the susceptible form is more common (MSSA), but as the antibiotic is applied, the bacteria that does not die (MRSA) will become more common. The mutation has created genes that break down the antibiotic. As antibiotics are used across time, MRSA increasingly survives and becomes more common. This can be a serious problem in hospitals and treatment.