Abstract
Introduction Typhoid fever, caused by Salmonella typhi and paratyphi, is a generalized infection with case fatality of about 10%. The symptoms may be
severe, with life threatening sequelae of infection in a proportion of cases. Antimicrobial
agents are the mainstay of therapy in enteric fever so as to prevent the complications
associated with severe illness and mortality in the patients. Fluoroquinolones (e.g.,
ciprofloxacin) are very effective against completely susceptible Salmonella bacteria. However, their efficacy is doubtful once any resistance is detected. Pefloxacin
testing has ultimately helped in the accurate identification of quinolone susceptibility
for a better therapeutic success rate. In the present study we have tried to evaluate
the quinolone susceptibility in Salmonella isolates based on minimum inhibitory concentration (MIC) determination.
Materials and Methods The method used in the study is quinolone susceptibility in Salmonella isolates based on MIC determination. Salmonella isolates show intermediate susceptibility to ciprofloxacin using disk diffusion.
Both ciprofloxacin and pefloxacin MIC evaluation has been done to corroborate the
results with pefloxacin disk diffusion testing.
Results There was a positive correlation between the susceptibility to ciprofloxacin and
pefloxacin. However, the isolates with intermediate susceptibility had variations
in terms of susceptibility to pefloxacin. MIC values for pefloxacin and our findings
suggested that pefloxacin susceptible on disk diffusion as per Clinical and Laboratory
Standards Institute guidelines showed lower values for MIC using Pefloxacin HICOMB
test and pefloxacin resistant isolates showed higher MIC values.
Keywords
MIC determination - pefloxacin - pefloxacin susceptible - quinolone susceptibility
-
Salmonella isolates
