Quinolone Antibiotics in the Treatment of Salmonella Infections

The 4-fluoroquinolones are a new class of antimicrobial agents that possess broad in vitro antibacterial activity, including efficacy against enteric pathogens such as Salmonella, Shigella, Campylobacter, Yersinia, and Vibrio species. These drugs are clinically effective against both drug-sensitive and multiresistant strains of Salmonella typhi and Salmonella paratyphi that cause enteric fever. In salmonella enterocolitis, the quinolones--unlike older antimicrobial agents that may have little impact on the duration of symptomatic illness and can in fact prolong fecal carriage of salmonellae--actually shorten the course of clinical disease and terminate excretion of these organisms in the stool. Similarly, for chronic carriers of both typhoidal and nontyphoidal Salmonella strains, the quinolones are effective in eradicating biliary and fecal reservoirs of infection. Immunosuppressed persons with salmonellosis, such as those with AIDS, may benefit from both short-term treatment and prolonged prophylaxis with a quinolone antibiotic. The optimal agent, dose, and duration of quinolone therapy for all salmonella syndromes remain to be determined by larger controlled trials.