In the treatment of infections caused by P. aeruginosa, the antimicrobial agent that has proved to be effective is
1.Penicillin G
2.Penicillin
3.Nafcillin
4.Erythromycin
5.Tetracycline
Explanation
Piperacillin is a broadspectrum, semisynthetic penicillin for parenteral use. Its spectrum of activity includes various Gram-positive and Gram-negative organisms including Pseudomonas. The indications for piperacillin are similar to those for carbenicillin, ticarcillin, and mezlocillin, with the primary use being sus-pected or proven infections caused by P. aeruginosa. Penicillin G, nafcillin, erythromycin, and tetracycline are ineffective against Pseudomonas.