If you have an infected cut or are developing a systemic infection, see a doctor. Once a cut gets infected, you’re going to need a doctor’s help. Once an infection is identified, antibiotics will be necessary to eliminate it. There are many antibiotics available, and different antibiotics work on different bacteria.
To figure out which drug is right for your situation, the physician might need to swab your injury and send the swab to be cultured. The material will be examined microscopically and will be placed in culture media to see if any concerning bacteria grow.
As soon as the bacteria grow enough, the exact types will be identified. If nothing concerning grows other than what is expected from healthy skin, the cut is not infected and no antibiotics will be needed. If concerning bacteria are found, they are tested to see which antibiotics are best at killing them and stopping the infection.