title: A factor found in aged tungstate solution enhanced the antibacterial effect of beta-lactams on methicillin-resistant Staphylococcus aureus.
abstract: We have found a factor (Factor T) in aged mixtures of tungstate and phosphate which greatly enhances the antibacterial effects of beta-lactams on both inducible and constitutive methicillin-resistant Staphylococcus aureus, but not on methicillin-susceptible S. aureus. Factor T alone did not strongly inhibit bacterial growth. There was no synergism of Factor T with other classes of antibiotics, nor with other groups of bacteria, and it reduced the efficacy of amino-glycosides and tetracycline. Upon preparation of Factor T, acidifying and heating the mixture of tungstate and phosphate resulted in a high yield and reproducibility, and no enhancing effect was observed when other anions such as sulfate or molybdate were used instead. Factor T is heat- and acid-stable but labile to alkalization, and is probably a complex of phosphate and tungstate.
authors.affiliation: Clinical Laboratory, Saga Medical School Hospital, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Tajima
authors.forename: Z
authors.initials: Z
authors.lastname: Nagasawa
authors.forename: J
authors.initials: J
authors.lastname: Tadano
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests; D012996:Solutions; D013045:Species Specificity; D013211:Staphylococcus aureus / Q000187:drug effects*; D017973:Tungsten Compounds / Q000737:chemistry / Q000494:pharmacology*; D047090:beta-Lactams
chemical_list: D000900:Anti-Bacterial Agents; D012996:Solutions; D017973:Tungsten Compounds; D047090:beta-Lactams