title: Magneto-actuated immunoassay for the detection of Mycobacterium fortuitum in hemodialysis water.
abstract: This paper addresses a sensitive method for the detection of mycobacteria in hemodialysis water samples based on a magneto-actuated immunoassay with optical readout. In this approach, micro (2.8μm) sized magnetic particles were modified with an antibody against the lipoarabinomannan (LAM) located in the mycobacterial cell wall. The system relies on the immunocapturing of the mycobacteria with the tailored antiLAM magnetic particles to pre-concentrate the bacteria from the hemodialysis samples throughout an immunological reaction. The performance of the immunomagnetic separation on the magnetic carrier was evaluated using confocal microscopy to study the binding pattern, as well as a magneto-actuated immunoassay with optical readout for the rapid detection of the bacteria in spiked hemodialysis samples. In this approach, the antiLAM polyclonal antibody was labeled with fluorescein isothiocyanate. The optical readout was achieved by the incubation with a secondary anti-fluorescein antibody labeled with peroxidase as optical reporter. The magneto-actuated immunoassay was able to detect mycobacteria contamination in hemodialysis water at a limit of detection of 13CFUmL(-1) in a total assay time of 3h without any previous culturing pre-enrichment step.
authors.affiliation: Grup de Sensors i Biosensors, Departament de Química, Universitat Autònoma de Barcelona, Bellaterra, Spain; Department of Analytical Chemistry, Institute of Chemistry, UNESP-Univ Estadual Paulista, Araraquara, SP, Brazil.
authors.forename: Michelle Fernanda
authors.initials: MF
authors.lastname: Brugnera
authors.affiliation: Grup de Sensors i Biosensors, Departament de Química, Universitat Autònoma de Barcelona, Bellaterra, Spain; Department of Chemistry, College of Arts and Sciences, Angeles University Foundation, Angeles City, Philippines.
authors.forename: Reynaldo
authors.initials: R
authors.lastname: Bundalian
authors.affiliation: Grup de Sensors i Biosensors, Departament de Química, Universitat Autònoma de Barcelona, Bellaterra, Spain.
authors.forename: Tamara
authors.initials: T
authors.lastname: Laube
authors.affiliation: Departament de Genética i de Microbiologia, Facultat de Biociències, Universitat Autònoma de Barcelona, Bellaterra, Spain.
authors.forename: Esther
authors.initials: E
authors.lastname: Julián
authors.affiliation: Departament de Genética i de Microbiologia, Facultat de Biociències, Universitat Autònoma de Barcelona, Bellaterra, Spain.
authors.forename: Marina
authors.initials: M
authors.lastname: Luquin
authors.affiliation: Department of Analytical Chemistry, Institute of Chemistry, UNESP-Univ Estadual Paulista, Araraquara, SP, Brazil.
authors.forename: Maria Valnice Boldrin
authors.initials: MV
authors.lastname: Zanoni
authors.affiliation: Grup de Sensors i Biosensors, Departament de Química, Universitat Autònoma de Barcelona, Bellaterra, Spain. Electronic address: isabel.pividori@uab.cat.
authors.forename: Maria Isabel
authors.initials: MI
authors.lastname: Pividori
mesh_terms: D007118:Immunoassay; D018189:Immunomagnetic Separation; D008280:Magnetics; D019907:Mycobacterium fortuitum; D006435:Renal Dialysis; D014867:Water
chemical_list: D014867:Water
keywords: Hemodialysis water; Immunomagnetic separation; Magneto-actuated immunoassay; Mycobacterium fortuitum