title: In vitro effect of free and complexed indium(III) against Mycobacterium tuberculosis.
abstract: In mycobacteria, the study of inhibition by metal ions has been limited by the absence of suitable molecular vectors. Recently, we reported on the inhibitory activity of a family of chelators, macrocyclic compounds (MCC), against Mycobacterium tuberculosis. In this study equimolar concentrations of the free cations vanadium(IV), arsenic(III), iron(III), indium(III) and bismuth(III), and as 1:1 complexes with the MCC 1,4,8,11-tetraazacyclotetradecane-1,4,8,11-tetra-acetic acid (TETA) were tested in vitro against M. tuberculosis using the Bactec 460 TB radiometric technology (Becton-Dickinson, MD, USA). Radiometric inhibition above 80% was obtained with free indium(III) and bismuth(III), and ranged from 80% to 99%, with the complexes of TETA with vanadium(IV), bismuth(III) and indium(III), in the order of increasing activity. The highest radiometric inhibition levels were obtained with the [In(TETA)]- complex, which caused drops of up to 4 log units in cellular viability. The minimal inhibitory concentration of this compound was evaluated at 3 microM.
authors.affiliation: Mycobacteriology Unit, Instituto de Higiéne e Medicina Tropical, Universidade Nova de Lisboa (UNL), Rua da Junqueira 96, 1349-008, Lisbon, Portugal. suzanadavid@ihmt.unl.pt
authors.forename: Suzana
authors.initials: S
authors.lastname: David
authors.forename: Vanessa
authors.initials: V
authors.lastname: Barros
authors.forename: Carla
authors.initials: C
authors.lastname: Cruz
authors.forename: Rita
authors.initials: R
authors.lastname: Delgado
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001151:Arsenic / Q000494:pharmacology; D001729:Bismuth / Q000494:pharmacology; D015169:Colony Count, Microbial; D007204:Indium / Q000494:pharmacology*; D007501:Iron / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000254:growth & development; D014639:Vanadium / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D014639:Vanadium; D007204:Indium; D007501:Iron; D001151:Arsenic; D001729:Bismuth