title: Effect of growth conditions on antimicrobial activity of DU-6859a and its bactericidal activity determined by the killing curve method.
abstract: The effect of growth conditions on the antibacterial activity of DU-6859a against Staphylococcus auerus, Escherichia coli, and Pseudomonas aeruginosa was compared with those of levofloxacin, sparfloxacin, and ciprofloxacin. This activity was not affected by different media, inoculum size or the addition of human serum, but was decreased under acidic conditions, in human urine, and in the presence of magnesium and ferrous ion, as were the other quinolones tested. Time-kill curve studies demonstrated the bactericidal action of DU-6859a against S. aureus, Streptococcus pneumoniae, E. coli, and P. aeruginosa. Morphological alteration of these bacteria after exposure to DU-6859a also demonstrated its bactericidal activity. The frequency of spontaneous resistance to DU-6859a was less than or equal to those of the reference drugs.
authors.affiliation: New Product Research Laboratories I, Daiichi Pharmaceutical Co, Ltd., Tokyo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Tanaka
authors.forename: K
authors.initials: K
authors.lastname: Hoshino
authors.forename: M
authors.initials: M
authors.lastname: Hohmura
authors.forename: H
authors.initials: H
authors.lastname: Ishida
authors.forename: A
authors.initials: A
authors.lastname: Kitamura
authors.forename: K
authors.initials: K
authors.lastname: Sato
authors.forename: I
authors.initials: I
authors.lastname: Hayakawa
authors.forename: T
authors.initials: T
authors.lastname: Nishino
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects; D002939:Ciprofloxacin / Q000494:pharmacology; D003470:Culture Media; D016895:Culture Media, Serum-Free; D004352:Drug Resistance, Microbial / Q000502:physiology; D004926:Escherichia coli / Q000187:drug effects / Q000254:growth & development; D024841:Fluoroquinolones; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D064704:Levofloxacin; D008670:Metals / Q000737:chemistry / Q000494:pharmacology; D008826:Microbial Sensitivity Tests / Q000379:methods*; D008854:Microscopy, Electron; D015242:Ofloxacin / Q000494:pharmacology; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000254:growth & development; D015363:Quinolones / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000187:drug effects / Q000254:growth & development; D014556:Urine / Q000382:microbiology
chemical_list: D000890:Anti-Infective Agents; D003470:Culture Media; D016895:Culture Media, Serum-Free; D024841:Fluoroquinolones; D008670:Metals; D015363:Quinolones; D002939:Ciprofloxacin; D064704:Levofloxacin; C076246:sitafloxacin; D015242:Ofloxacin; C061363:sparfloxacin