Predictive efficacy of nalidixic acid resistance as a marker of fluoroquinolone resistance in Salmonella enterica var Typhi.

Abstract

NA susceptibility was a good marker for fluoroquinolone susceptibility but NA resistance had a poor predictive value for ciprofloxacin resistance. NA resistant isolates should be tested for ciprofloxacin MIC before deciding a change in therapeutic regimen. Higher MIC for gatifloxacin was also noticed in NA resistant isolates.