Salmonella bacteria are one of the most common causes of foodborne illness around the world, according to the World Health Organization . In the United States alone, 1.4 million infections result in more than150,000 doctor visits, 15,000 hospitalizations and 500 deaths each year, according to the WHO. Although drug treatment is required in only 2 percent of cases, drug resistance is a growing problem.
Quinolones and Fluoroquinolones
Quinolones and fluoroquinolones are the "drugs of choice" in the treatment of salmonella in adults, according to the WHO. Examples of quinolones and fluoroquinolones used to treat salmonella include ciprofloxacin, levofloxacin, norfloxacin and ofloxacin. Drugs in this family inactivate a bacterial enzyme called topoisomerase II which unwinds DNA in preparation for duplication. Compared to earlier drugs, quinolones and fluoroquinolones are relatively inexpensive, well-tolerated and rapidly effective. Rare but serious side effects of quinolones and fluoroquinolones include abnormal heart rhythms, seizures, tendon rupture and low blood sugar. Quinolones and fluoroquinolones should not be taken by pregnant women because they are associated with birth defects.
Cephalosporins
Third-generation cephalosporins are widely used in children with serious infections because of the relatively high risk of tendon rupture and abnormal collagen production with quinolones and fluoroquinones in children. The most common choices are cefotaxime and ceftriaxone, according to the WHO.
Much like penicillins, cephalosporins work by disrupting the structure of bacterial cell walls, causing them the break open. Unlike penicillins, cephalosporins are classified as beta-lactams because they are effective against bacteria which produce the enzyme beta-lactamase. The drugs are given intravenously or intramuscularly; they are not effective orally. In children, this may be an advantage. Rare but serious side effects include seizures, decrease in certain kinds of white blood cells, decrease in red blood cells (anemia), liver problems, and severe diarrhea.
Other Drugs
Earlier drugs such as chloramphenicol, ampicillin, amoxicillin and trimethoprim-sulfamethoxazole are still occasionally used as alternatives when other drugs are not available, not effective or not appropriate due to allergy or other reasons. They may be used as single agents or as adjuncts in cases of drug-resistant salmonella.
Drug resistance is an increasing problem around the world due to the widespread use of antibiotics. While doctors may begin treating salmonella infections presumptively, in almost all cases "culture and sensitivity" tests will also be ordered. These confirm the diagnosis and identify drugs resistance where it occurs.
