title: Differentiation of Aeromonas isolated from drinking water distribution systems using matrix-assisted laser desorption/ionization-mass spectrometry.
abstract: The genus Aeromonas is one of several medically significant genera that have gained prominence due to their evolving taxonomy and controversial role in human diseases. In this study, matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) was used to analyze the whole cells of both reference strains and unknown Aeromonas isolates obtained from water distribution systems. A library of over 45 unique m/z signatures was created from 40 strains that are representative of the 17 recognized species of Aeromonas, as well as 3 reference strains from genus Vibrio and 2 reference strains from Plesiomonas shigelloides. The library was used to help speciate 52 isolates of Aeromonas. The environmental isolates were broken up into 2 blind studies. Group 1 contained isolates that had a recognizable phenotypic profile and group 2 contained isolates that had an atypical phenotypic profile. MALDI-MS analysis of the water isolates in group 1 matched the phenotypic identification in all cases. In group 2, the MALDI-MS-based determination confirmed the identity of 18 of the 27 isolates. These results demonstrate that MALDI-MS analysis can rapidly and accurately classify species of the genus Aeromonas, making it a powerful tool especially suited for environmental monitoring and detection of microbial hazards in drinking water.
authors.affiliation: National Exposure Research Laboratory, Office of Ground Water and Drinking Water, National Council on the Aging, and National Risk Management Research Laboratory, U.S. Environmental Protection Agency, Cincinnati, Ohio 45268, USA. Donohue.maura@epa.gov
authors.forename: Maura J
authors.initials: MJ
authors.lastname: Donohue
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Best
authors.forename: Anthony W
authors.initials: AW
authors.lastname: Smallwood
authors.forename: Mitchell
authors.initials: M
authors.lastname: Kostich
authors.forename: Mark
authors.initials: M
authors.lastname: Rodgers
authors.forename: Jody A
authors.initials: JA
authors.lastname: Shoemaker
mesh_terms: D000333:Aeromonas / Q000145:classification* / Q000302:isolation & purification; D015373:Bacterial Typing Techniques / Q000379:methods*; D004784:Environmental Monitoring / Q000379:methods*; D010802:Phylogeny; D016981:Plesiomonas / Q000145:classification; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D014733:Vibrio / Q000145:classification; D014871:Water Microbiology; D014881:Water Supply