Protein- and RNA-synthesis independent bactericidal activity of ciprofloxacin that involves the A subunit of DNA gyrase.
Ciprofloxacin, unlike nalidixic acid, can kill Escherichia coli cells in the absence of synthesis of protein or RNA. Hence, chloramphenicol or rifampicin do not abolish the bactericidal activity of ciprofloxacin against wild-type E. coli. Protein and RNA synthesis were not required for the bactericidal activity of ciprofloxacin against nalB, nalC and nalD mutants of E. coli. However, the addition of chloramphenicol or rifampicin abolished the bactericidal activity of ciprofloxacin against a nalA mutant in nutrient broth. It is concluded that the ability of ciprofloxacin to kill E. coli in the absence of protein or RNA synthesis involves the A subunit of DNA gyrase.
Department of Bacteriology, University of Edinburgh Medical School.
C S
CS
Lewin
B M
BM
Howard
J T
JT
Smith
D002463:Cell Membrane Permeability / Q000187:drug effects; D002702:Chloramphenicol Resistance; D002939:Ciprofloxacin / Q000494:pharmacology*; D004250:DNA Topoisomerases, Type II / Q000096:biosynthesis*; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D008826:Microbial Sensitivity Tests; D009154:Mutation; D009268:Nalidixic Acid / Q000494:pharmacology; D012329:RNA, Bacterial / Q000096:biosynthesis*; D012293:Rifampin / Q000494:pharmacology
D012329:RNA, Bacterial; D009268:Nalidixic Acid; D002939:Ciprofloxacin; D004250:DNA Topoisomerases, Type II; D012293:Rifampin