Synergism of ciprofloxacin and trimethoprim against Salmonella enterica serovar typhi isolates showing reduced susceptibility to ciprofloxacin.
The activity of the combination of ciprofloxacin and trimethoprim against 16 Salmonella enterica serovar typhi isolates from blood cultures were tested by agar dilution checkerboard technique. When used in combination, minimum inhibitory concentrations (MICs) of ciprofloxacin and trimethoprim ranged from 0.5 to 1.25 and from 10 to 125 microg/ml, respectively, and fractional inhibitory concentrations (FICs) from 0.025 to 0.125 and from 2.5 to 10 microg/ml, respectively. The FIC index was 0.140-0.483, indicating a marked synergy between ciprofloxacin and trimethoprim against trimethoprim-resistant S. enterica serovar typhi isolates (100%) with high MICs for ciprofloxacin.
Department of Bacteriology and Serology, Calcutta School of Tropical Medicine, C.R. Avenue, Calcutta, India.
Shyamapada
S
Mandal
Manisha Deb
MD
Mandal
Nishith Kumar
NK
Pal
D000890:Anti-Infective Agents / Q000494:pharmacology*; D002939:Ciprofloxacin / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial; D004357:Drug Synergism; D006801:Humans; D008826:Microbial Sensitivity Tests; D012485:Salmonella typhi / Q000187:drug effects* / Q000302:isolation & purification; D014295:Trimethoprim / Q000494:pharmacology*
D000890:Anti-Infective Agents; D002939:Ciprofloxacin; D014295:Trimethoprim