title: Discrimination of single-porin Escherichia (E.) coli mutants by ATR and transmission mode FTIR spectroscopy.
abstract: Vibrational spectroscopy has long been used in bacterial identification with different levels of taxonomic discrimination but its true potential for intra-species differentiation remains poorly explored. Herein, both transmission Fourier-transform infrared (FTIR) and attenuated total reflectance (ATR)-FTIR spectroscopy are used to analyse E. coli strains that differ solely in their porin expression profile. In this previously unreported approach, the applicability of both FTIR-spectroscopy techniques is compared with the same collection of unique strains. ATR-FTIR spectroscopy proved to reliably distinguish between several E. coli porin mutants with an accuracy not replicated by FTIR in transmission mode (using previously optimized procedures). Further studies should allow the identification of the individual contribution of the single porin channel to the overall bacterial infrared spectrum and of molecular predictive patterns of porin alterations.
authors.affiliation: REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, R. do Campo Alegre, 4169-007 Porto, Portugal.
authors.forename: Raúl G
authors.initials: RG
authors.lastname: Saraiva
authors.forename: João Almeida
authors.initials: JA
authors.lastname: Lopes
authors.forename: Jorge
authors.initials: J
authors.lastname: Machado
authors.forename: Paula
authors.initials: P
authors.lastname: Gameiro
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Feio
mesh_terms: D024881:Drug Resistance, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics*; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics; D008958:Models, Molecular; D009154:Mutation; D018272:Porins / Q000737:chemistry* / Q000235:genetics; D011487:Protein Conformation; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*
chemical_list: D029968:Escherichia coli Proteins; D018272:Porins