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Chloramphenicol-resistant Salmonella typhi in Saigon
JAMA
|January 13, 1975
Summary
Chloramphenicol-resistant Salmonella typhi emerged in Saigon in 1971. Alternative antibiotics like ampicillin and trimethoprim-sulfamethoxazole proved effective against these resistant strains.
Area of Science:
- Microbiology
- Infectious Diseases
- Pharmacology
Background:
- Emergence of antibiotic resistance in bacterial pathogens poses a significant public health threat.
- Salmonella typhi is a major cause of typhoid fever, a systemic infection.
- Chloramphenicol was a primary treatment for typhoid fever before the rise of resistance.
Purpose of the Study:
- To investigate the prevalence of chloramphenicol-resistant Salmonella typhi in Saigon.
- To evaluate the susceptibility of these resistant strains to alternative antibiotics.
- To assess the clinical efficacy of different treatment options for infections caused by resistant strains.
Main Methods:
- Isolation and identification of Salmonella typhi strains from clinical samples.
- Agar-disk diffusion method to determine chloramphenicol resistance.
- Broth-dilution method to determine minimal inhibitory concentrations (MICs) for chloramphenicol and other antibiotics.
- Clinical response assessment for patients treated with chloramphenicol, ampicillin, or trimethoprim-sulfamethoxazole.
Main Results:
- 46% of isolated Salmonella typhi strains in Saigon (1971) exhibited chloramphenicol resistance.
- 37% of studied strains showed high MICs for chloramphenicol (>250 µg/ml).
- All resistant strains remained susceptible to ampicillin (0.4 µg/ml MIC) and trimethoprim-sulfamethoxazole.
Conclusions:
- Chloramphenicol resistance in Salmonella typhi was a significant issue in Saigon in 1971.
- Ampicillin and trimethoprim-sulfamethoxazole represent effective therapeutic alternatives for treating chloramphenicol-resistant typhoid fever.
- The findings underscore the need for continuous surveillance of antibiotic resistance patterns.
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