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Chloramphenicol drug failure in typhoid fever
S S El-Din1, N M Haseeb, M M Hussein
1Department of Tropical Medicine, Faculty of Medicine, Ain Shams University, Cairo.
The Journal of the Egyptian Public Health Association
|January 1, 1996
Summary
Twenty-five percent of typhoid patients exhibited resistance to chloramphenicol, despite therapeutic drug levels. This highlights the challenge of chloramphenicol resistance in Salmonella Typhi infections.
Area of Science:
- Infectious Diseases
- Microbiology
- Pharmacology
Background:
- Typhoid fever remains a significant global health concern.
- Chloramphenicol has been a cornerstone treatment, but resistance is emerging.
- Understanding resistance mechanisms is crucial for effective management.
Purpose of the Study:
- To assess the prevalence of chloramphenicol resistance in Salmonella Typhi isolates.
- To investigate the correlation between in vitro resistance and clinical outcomes.
- To evaluate chloramphenicol drug levels in patients with varying susceptibility.
Main Methods:
- Prospective study of 200 typhoid patients.
- Inclusion of clinical evaluation, blood/urine/stool cultures, Widal test.
- Antimicrobial susceptibility testing (disk diffusion, MIC), chloramphenicol acetyltransferase assay, and serum drug level monitoring.
Main Results:
- 25% of patients (50/200) showed resistance to chloramphenicol.
- Resistant isolates exhibited reduced susceptibility zone sizes and increased MICs.
- All resistant isolates were positive for chloramphenicol acetyltransferase.
- No significant difference in serum chloramphenicol levels between susceptible and resistant groups.
Conclusions:
- A significant proportion of typhoid cases in the studied population exhibit chloramphenicol resistance.
- Chloramphenicol acetyltransferase is a key mechanism for this resistance.
- Therapeutic drug monitoring did not differentiate between susceptible and resistant groups.
- Alternative antibiotics like quinolones or cephalosporins are necessary for resistant cases.
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