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Quinolones in the treatment of Salmonella carriers
E Rodríguez-Noriega1, J Andrade-Villanueva, G Amaya-Tapia
1Infectious Diseases Division, Universidad de Guadalajara, Complejo Médico, Hospital Civil de Guadalajara, Jalisco, Mexico.
Abstract:
Infections caused by Salmonella typhi are commonly followed by a chronic carrier state despite positive clinical and initial bacteriologic responses. The use of primary antibiotics like chloramphenicol, ampicillin, and trimethoprim-sulfamethoxazole has several major drawbacks, including in some instances the failure to prevent the carrier state. The appearance worldwide of strains with multiple resistance to the most commonly used regimens has prompted the search for new forms of therapy. Among the agents studied have been third-generation cephalosporins and quinolones, which are active in vitro against bacterial enteropathogens like S. typhi. Resolution of chronic carriage of S. typhi and other salmonellae is difficult, and regimens commonly fail (including those that combine antibiotic administration with removal of the gallbladder). In addition to being active in vitro against Salmonella species, the newer quinolones adequately penetrate the intestinal lumen, liver, bile, and gallbladder. Initial experience with norfloxacin and ciprofloxacin in oral treatment of the chronic S. typhi carrier state in adults has been promising.
Insights
Newer quinolones show promise for treating chronic Salmonella typhi carriers when traditional antibiotics fail. These drugs effectively target resistant strains and reach key infection sites like the liver and gallbladder.
Area of Science:
- Infectious Diseases
- Microbiology
- Pharmacology
Background:
- Chronic Salmonella typhi carrier state persists despite initial treatment.
- Common antibiotics (chloramphenicol, ampicillin, trimethoprim-sulfamethoxazole) often fail to eradicate carriage.
- Increasing antibiotic resistance in Salmonella typhi necessitates novel therapeutic approaches.
Purpose of the Study:
- To evaluate the efficacy of newer antimicrobial agents against chronic Salmonella typhi carriers.
- To explore alternative treatments for persistent Salmonella typhi infections unresponsive to conventional therapies.
Main Methods:
- In vitro susceptibility testing of Salmonella typhi against third-generation cephalosporins and quinolones.
- Assessment of newer quinolones' penetration into intestinal lumen, liver, bile, and gallbladder.
- Review of initial clinical experiences with oral norfloxacin and ciprofloxacin in chronic carriers.
Main Results:
- Third-generation cephalosporins and quinolones demonstrate in vitro activity against Salmonella typhi.
- Newer quinolones exhibit favorable pharmacokinetic properties, including penetration into relevant tissues.
- Preliminary data suggest oral norfloxacin and ciprofloxacin are effective in resolving chronic Salmonella typhi carriage in adults.
Conclusions:
- Novel quinolone antibiotics represent a promising therapeutic option for chronic Salmonella typhi carriers.
- Effective treatment of chronic carriage may require agents with good tissue penetration, including into the biliary system.
- Further clinical studies are warranted to confirm the efficacy and safety of these agents.