MS-H: A Novel Proteomic Approach to Isolate and Type the E. coli H Antigen Using Membrane Filtration and Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)

摘要: Serotyping is the long-standing gold standard method to determine E. coli H antigens; however, this requires a panel of H-antigen specific antibodies and often culture-based induction flagellar motility. In study, rapid accurate isolate identify Escherichia (E. coli) antigen was developed using membrane filtration liquid chromatography-tandem mass spectrometry (LC-MS/MS). Flagella were isolated from pure culture, digested with trypsin, then subjected LC-MS/MS one two systems (Agilent-nano-LC-QSTAR XL or Proxeon-nano-LC-LTQ-Orbitrap XL). The resulting peptide sequence data searched against custom flagella/H database. This approach evaluated flagella reference strains representing all 53 known types 41 clinical strains. classifications (MS-H) concordant serogroup for types, isolates tested, 38 (92.7%) serogroup. MS-H clearly also identified (4.9%) that untypeable by serotyping. Notably, successful detection classification antigens did not generally require motility, establishing proteomic as more cost-effective than traditional methods, while providing equitable specificity typing antigens.