Re-emergence of susceptibility to conventionally used drugs among strains of Salmonella Typhi in central west India

Abstract

Introduction: Typhoid fever (enteric fever) is a global health problem causing high morbidity and mortality, especially in endemic areas such as India. The problem is exacerbated as the causative agent, Salmonella enterica subspecies enterica serovar Typhi (S. Typhi), rapidly develops resistance to drugs used in treatment. However, non-responsiveness of S. Typhi to quinolones has been reported simultaneously with the re-emergence of susceptibility to chloramphenicol. The present study investigates the re-emergence of sensitivity to conventionally used drugs among strains of S. Typhi in the central west part of India. Methodology: We evaluated 128 S. Typhi isolates received at the National Salmonella and Escherichia Centre for chloramphenicol, ampicillin and trimethoprim susceptibility using standard methods. Minimum inhibitory concentrations were also evaluated. Results: The proportion of S. Typhi isolates showing susceptibility to chloramphenicol, ampicillin, and trimethoprim was 95.3%, 94.5%, and 94.5%, respectively. These findings may help the health authorities in reconsidering the addition of these antimicrobial drugs into the treatment regime of typhoid fever and therefore may help combat the problem of increasing resistance to quinolones and cephalosporins. Conclusion: The changing trends of S. Typhi resistance patterns necessitate reconsideration of conventionally used drugs in typhoid fever treatment in India. In the present study, S. Typhi strains exhibited increased susceptibility toward chloramphenicol, ampicillin and trimethoprim, therefore suggesting the possibility of their use for treatment of typhoid fever.