Sulfamethizole

Sulfamethizole is a sulfathiazole antibiotic. Sulfamethizole inhibits the synthesis of folic acid and thymine, and selectively suppresses Photobacterium phosphoreum bioluminescence. Sulfamethizole exerts antibacterial activity against Escherichia coli-mediated urinary tract infections but no activity against sulII gene-positive Escherichia coli. Sulfamethizole is applicable for the research of urinary tract infections and Photobacterium phosphoreum bioluminescence mechanisms^[1][2]. In Vitro:Sulfamethizole (3×10^-4-10^-3 M; 5-14 h) does not reduce in vitro luciferase or flavin reductase activities in cell-free extracts from Photobacterium phosphoreum strain 496 after 5 h and 14 h of incubation, with over 90% of extractable specific enzyme activity retained at 5 h for both concentrations^[1].
Sulfamethizole exhibits distinct in vitro MIC values against different type 1-fimbriated E. coli clinical isolates, with MICs of 128 μg/mL, 512 μg/mL, and > 2048 μg/mL for strains KMA-26883, UVI-203, and KMA-28523, respectively^[2]. In Vivo:Sulfamethizole (1.25 mg; s.c.; twice daily; 3 days) produces significant dose-dependent reductions in bacterial counts in urine, bladder, and kidneys of infected mice for E. coli strains with MICs ≤ 512 μg/mL, but has no effect on a sulII gene-positive strain with an MIC > 2048 μg/mL^[2].