Antibiotics are used to cure typhoid fever victims. The Salmonella typhi bacteria have developed, and continue to develop, immunity to several antibiotics. Outbreaks in areas of South America have been known for major resistance to many antibiotics. Fluoroquinolones are the main type of antibiotic that typhoid fever has shown resistance to. Fluoroquinolones, or just quinolones, are a group of relatively generic antibiotics that work on both gram-negative and gram-positive bacterium. Chloramphenicol was the original antibiotic of choice until the medicine was found to have rare but deadly side effects.
Antibiotics that are still used to treat typhoid and be known to work are ceftriaxone and azithromycin. Patients who do not have access continue to have the illness for weeks or, in extreme cases, months. Untreated typhoid fever has a mortality rate of about 20 percent. The mortality rate of treated typhoid is only 1-2 percent.
Antibiotics work by killing all the bacteria in your body that infected you with an illness. Antibiotics kill the Salmonella typhi bacteria to cure you of typhoid. To kill the bacteria, the antibiotic deprives the cell wall of the bacteria of a very important molecule that provides the cell wall with enough strength to keep the bacteria alive in the human body and continue to infect a human. It typically takes about 1-2 days after antibiotics are first taken for a patient to feel better and only about a week until patients are completely recovered.
3-5 percent of all become chronically ill/carriers of typhoid. Those must take special measures to make sure they do not spread the disease to others. One way to protect themselves and others around them is to take long-term antibiotics.
Here is a common quinolone, Levaquin. While this medicine might not necessarily be used for typhoid, it kills bacteria in the same way
This gif shows how antibiotics work to kill bacteria.