High level ciprofloxacin resistance in Salmonella enterica isolated from blood

Indian J Med Microbiol. 2008 Jan-Mar;26(1):50-3. doi: 10.4103/0255-0857.38858.

Abstract

Purpose: Over the last few years, resistance to ciprofloxacin in Salmonella enterica has become a global concern. The present study was undertaken to find out the susceptibility pattern of Salmonella enterica isolates in our hospital.

Methods: Blood cultures were done using BacT/ALERT 3D system. The antimicrobial susceptibility testing was carried out by the Kirby-Bauer disc diffusion method using CLSI breakpoints. Minimum inhibitory concentration was determined for ciprofloxacin-resistant strains using E-test and Vitek-1 automated system.

Results: A total of 25,953 samples of blood culture yielded 431 Salmonella enterica serotype Typhi and 198 serotype Paratyphi A isolates. Twenty-two isolates of serotype Typhi were resistant to ciprofloxacin, while two isolates of Typhi and two Paratyphi A were intermediately susceptible to ciprofloxacin. Ciprofloxacin resistance is 5.6% (24 isolates) among Salmonella enterica serotype Typhi. Ampicillin, chloramphenicol and co-trimoxazole resistance in Salmonella enterica serotype Typhi appears to have decreased to 14.9% (64/431) in comparison to the 27% (55/205) during 2003. All isolates were sensitive to ceftriaxone.

Conclusions: Ciprofloxacin can no longer be considered as the drug of choice in treating Salmonella infections. While first-line antimicrobials may still have a role to play in the treatment of enteric fever, ceftriaxone remains the sole defence against ciprofloxacin-resistant Salmonella infections.

MeSH terms

  • Anti-Bacterial Agents / pharmacology*
  • Bacteremia / microbiology*
  • Blood / microbiology
  • Ciprofloxacin / pharmacology*
  • Drug Resistance, Bacterial*
  • Humans
  • Microbial Sensitivity Tests
  • Paratyphoid Fever / microbiology*
  • Salmonella paratyphi A / drug effects*
  • Salmonella paratyphi A / isolation & purification
  • Salmonella typhi / drug effects*
  • Salmonella typhi / isolation & purification
  • Typhoid Fever / microbiology*

Substances

  • Anti-Bacterial Agents
  • Ciprofloxacin