What are the drugs of choice for treating infections with Enterobacteriaceae?

• A. Aminoglycosides, trimethoprim-sulfamethoxazole, third-generation cephalosporins
• B. Ampicillin and nalidixic acid
• C. Streptomycin and isoniazid
• D. Chloramphenicol, ampicillin, and colistin

Answer: (A)

The choice of drugs primarily used against Enterobacteriaceae is based on their effectiveness and the resistance patterns commonly observed in this family of bacteria. Aminoglycosides, trimethoprim-sulfamethoxazole, and third-generation cephalosporins are often considered the drugs of choice due to their broad-spectrum activity and the ability to target a variety of Enterobacteriaceae species.

Aminoglycosides are effective against many Gram-negative bacteria, including Enterobacteriaceae, by inhibiting protein synthesis. Trimethoprim-sulfamethoxazole provides a synergistic effect, inhibiting bacterial folic acid synthesis, which is crucial for growth and replication. Third-generation cephalosporins offer improved efficacy against certain resistant strains and are often a first-line treatment for serious infections caused by Enterobacteriaceae.

In contrast, the other options do not present a comprehensive approach or may not be effective against common strains of Enterobacteriaceae. Ampicillin and nalidixic acid, for instance, may be limited in their effectiveness due to resistance. Streptomycin and isoniazid are not typically employed for Enterobacteriaceae infections as they primarily target Mycobacterium species, particularly in tuberculosis. Lastly,