Ampicillin and sulbactam for injection is indicated for the treatment of infections due to susceptible strains of the designated microorganisms in the conditions listed below. Skin and Skin Structure Infections caused by beta-lactamase producing strains of Staphylococcus aureus, Escherichia coli,* Klebsiella spp.* , Proteus mirabilis,* Bacteroides fragilis,* Enterobacter spp.,* and Acinetobacter calcoaceticus.* NOTE: For information on use in pediatric patients. Intra-Abdominal Infections caused by beta-lactamase producing strains of Escherichia coli, Klebsiella spp. , Bacteroides spp. , and Enterobacter spp.* Gynecological Infections caused by beta-lactamase producing strains of Escherichia coli,* and Bacteroides spp.* . * Efficacy for this organism in this organ system was studied in fewer than 10 infections. While ampicillin and sulbactam for injection is indicated only for the conditions listed above, infections caused by ampicillin-susceptible organisms are also amenable to treatment with ampicillin and sulbactam for injection due to its ampicillin content. Therefore, mixed infections caused by ampicillin-susceptible organisms and beta-lactamase producing organisms susceptible to ampicillin and sulbactam for injection should not require the addition of another antibacterial. Appropriate culture and susceptibility tests should be performed before treatment in order to isolate and identify the organisms causing infection and to determine their susceptibility to ampicillin and sulbactam for injection. Therapy may be instituted prior to obtaining the results from bacteriological and susceptibility studies when there is reason to believe the infection may involve any of the beta-lactamase producing organisms listed above in the indicated organ systems. Once the results are known, therapy should be adjusted if appropriate. To reduce the development of drug-resistant bacteria and maintain effectiveness of ampicillin and sulbactam for injection and other antibacterial drugs, ampicillin and sulbactam for injection should be used only to treat infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.