TABLE 1

Synergistic activity of combinations of fluconazole and sulfonamide antibacterial drugs against different resistant strains of Candida albicans isolates

Sulfa drugMIC50 (μg/ml)aFIC indexInterpretationc
FLCSulfa drug
AloneIn combination (MICc)bAloneIn combination (MICc)
4-Amino phenyl sulfone (dapsone)5121512320.0625SYN
Sulfadiazine5120.5512320.0625SYN
Sulfamethazine1,024110241280.125SYN
Sulfamethoxazole5121512160.0312SYN
Sulfanilamide>1,024>128>1,024>1,0242IND
Sulfacetamide>1,024>128>1,024>1,0242IND
Sulfabenzimide>1,024>128>1,024>1,0242IND
Sulfadoxine5121512640.125SYN
Sulfanitran>1,024>128>1,024>1,0242IND
Sulfamerazine1,0240.51,0241280.125SYN
Sulfamonomethoxine5120.5512160.0312SYN
Sulfadimethoxine1,0240.51,024640.0625SYN
Succinylsulfathiazole>1,024>128>1,024>1,0242IND
Sulfathiazole1,0240.51,0241280.125SYN
Sulfaguanidine>1,024>128>1,024>1,0242IND
Sulfapyridine5121512640.125SYN
Sulfametopyrazine (sulfalene)1,0240.51,024640.0625SYN
Sulfametoxydiazine (sulfameter)5120.5512640.125SYN
Sulfisomidine1,0240.51,0241280.125SYN
Sulfisoxazole (sulfafurazole)1,02411,0241280.125SYN
Sulfamethoxypyridazine5121512320.0625SYN
  • a MIC50 is the lowest concentration of the drug that showed at least 80% reduction of the growth of 50% of the tested Candida strains.

  • b MICc is the MIC of the drug when used in combination with fluconazole.

  • c FIC index interpretations: ≤0.5, synergism (SYN); >0.5 to 4, indifferent (IND); >4, antagonism.