Treatment of infections due to gram-negative bacilli: a perspective of past, present, and future

Bacteremia due to gram-negative rods is a disease of the antimicrobial era. Mortality is critically related to the presence of underlying disease and to the appropriateness of therapy. During the last 15 years, survival has significantly improved for patients who have severe underlying disease and who are treated with aminoglycosides and beta-lactam agents possessing antipseudomonal activity. Newer broad-spectrum beta-lactam agents offer considerable therapeutic promise, but clinical results have been disappointing in serious infections caused by Enterobacter and Serratia species and a number of the "nonfermenting" bacilli, including Pseudomonas aeruginosa. A number of major problems exist in interpreting open or comparative clinical trials. Treatment of the critically ill patient with sepsis due to gram-negative bacteria will remain the definitive test of efficacy of any new broad-spectrum antimicrobial agent.