Related Experiment Videos
Multidrug resistant Salmonella typhi in Delhi
1Department of Microbiology, All India Institute of Medical Sciences, New Delhi.
Abstract:
In 1990, we isolated 158 strains of Salmonella typhi from blood cultures of patients suffering from typhoid fever. Seventy nine (50%) of these isolates were found to be simultaneously resistant to chloramphenicol, ampicillin and cotrimoxazole. These strains were also resistant to streptomycin and tetracycline, but sensitive to gentamicin, amikacin and cephalexin. The minimum inhibitory concentrations of chloramphenicol and trimethoprim for a representative number of these strains were found to be greater than 1024 micrograms/ml and greater than 128 micrograms/ml respectively. Majority of the multidrug resistant (MDR) strains tested against cefotaxime (23/23), ciprofloxacin (38/38) and amoxycillin plus clavulanic acid (23/24) were sensitive to these drugs.
Insights
In 1990, 50% of Salmonella typhi strains showed multidrug resistance (MDR) to common antibiotics like chloramphenicol. However, these strains remained sensitive to newer drugs such as ciprofloxacin, indicating potential treatment options.
Area of Science:
- Microbiology
- Infectious Diseases
- Antimicrobial Resistance
Background:
- Typhoid fever, caused by Salmonella typhi, remains a significant global health concern.
- The emergence of multidrug-resistant (MDR) Salmonella typhi strains poses a substantial challenge to effective treatment.
- Understanding resistance patterns is crucial for guiding antimicrobial therapy and public health strategies.
Purpose of the Study:
- To investigate the prevalence of multidrug resistance in Salmonella typhi isolates from typhoid fever patients.
- To determine the susceptibility profiles of resistant strains to a range of commonly used and newer antibiotics.
Main Methods:
- Isolation and identification of Salmonella typhi from blood cultures of patients diagnosed with typhoid fever.
- Antimicrobial susceptibility testing using standard microbiological methods.
- Determination of minimum inhibitory concentrations (MICs) for key antibiotics.
Main Results:
- Out of 158 Salmonella typhi isolates, 79 (50%) exhibited simultaneous resistance to chloramphenicol, ampicillin, and cotrimoxazole.
- These MDR strains were also resistant to streptomycin and tetracycline but remained sensitive to gentamicin, amikacin, and cephalexin.
- High minimum inhibitory concentrations (MICs) were observed for chloramphenicol (>1024 µg/ml) and trimethoprim (>128 µg/ml).
- A majority of MDR strains showed sensitivity to cefotaxime, ciprofloxacin, and amoxicillin-clavulanic acid.
Conclusions:
- A significant proportion of Salmonella typhi isolates in 1990 displayed multidrug resistance, highlighting a growing public health threat.
- While resistance to older antibiotics is prevalent, newer agents like ciprofloxacin and cefotaxime show promise for treating MDR typhoid fever.
- Continued surveillance of antimicrobial resistance patterns is essential for effective management of typhoid fever.