Indications: Infections caused by gram-positive aerobic bacteria Bronchitis otitis media,skin infections, sinusitis, and tonsilitis are often caused by strains of Streptococcus or Staphylococcus susceptible to amoxicillin. Infections caused by enterococci Urinary tract infections often respond to high urinary concentrations of amoxicillin. Endocarditis caused by these organisms is best treated simultaneously with an aminoglycoside and penicillin such as amoxicillin. Infections caused by gram-negative aerobic bacteria Susceptible bacteria may include Escherichia coli, Hemophilus influenzae, Neisseria gonorrhoeae, Proteus mirabilis, and Salmonella. These organisms commonly cause infections of the urinary tract. Hemophilus causes ear infections and meningitis. Prophylaxis Amoxicillin is used to prevent bacterial endocarditis in patients with prosthetic heart valves who must undergo minor procedures likely to seed bacteria into the blood, such as instrumentation of the genitourinary tract.