title: Multiple sample flow through immunomagnetic separator for concentrating pathogenic bacteria.
abstract: The standard method of immunomagnetic separation for isolating pathogenic bacteria from food and environmental matrices processes 1 ml volumes. Pathogens present at low levels (<0.5 pathogenic bacteria/g) will not be consistently detected by this method. Here a multiple sample flow through immunomagnetic separator has been designed and tested to process large volume samples (50 to 250 ml). Preliminary results show >97% recovery of polydisperse magnetic particles (diameter range 1 to 8 microm) containing 29-33% w/w Fe3O4 content. Between 70 and 130 times more of the pathogenic bacteria Escherichia coli O157 is recovered from PBS compared with the standard 1 ml method. Also, the recovery of E. coli O157 from beef mince homogenates, after a 4 h incubation at 42 degrees C, is between 80 and 180 times higher than the standard 1 ml method.
authors.affiliation: School of Biological Sciences, University of Aberdeen, Cruickshank Building, St. Machar Drive, Aberdeen, UK.
authors.forename: Ovidiu
authors.initials: O
authors.lastname: Rotariu
authors.forename: Iain D
authors.initials: ID
authors.lastname: Ogden
authors.forename: Marion
authors.initials: M
authors.lastname: MacRae
authors.forename: Laura Elena
authors.initials: LE
authors.lastname: Udrea
authors.forename: Norval J C
authors.initials: NJ
authors.lastname: Strachan
mesh_terms: D001419:Bacteria / Q000302:isolation & purification* / Q000472:pathogenicity*; D004867:Equipment Design; D004926:Escherichia coli / Q000302:isolation & purification / Q000472:pathogenicity; D005516:Food Microbiology; D018189:Immunomagnetic Separation / Q000295:instrumentation / Q000379:methods*; D012680:Sensitivity and Specificity