Ready, Set, Type! Proteomics vs Agglutination for Escherichia coli H Antigen Confirmation

[摘要] Initial detection and reporting by clinical microbiology laboratories is a sentinel marker for foodborne outbreak surveillance systems. Initiation of a public health investigation is reliant on the rapid initial identification of pathogens of interest (Fig. 1). Diagnostics for Escherichia coli have evolved to reduce identification turnaround time, incorporating technologies for rapid identification (MALDI-TOF MS) and serogrouping (O157 antiserum or latex agglutination) (1). Reporting of these isolates to a public health agency may initiate further laboratory investigations, such as pulsed-field gel electrophoresis, for confirmation that isolates may be related to a common source (clonal population). In addition, H antigen flagellar antigen testing with serotyping, or whole-genome sequencing, can be performed to confirm E. coli O157:H7 and other outbreak-associated strains.Fig. 1. Investigation of an E. coli outbreak [adapted from CDC (5)].Although methods used at either end of the outbreak investigation spectrum—initial bacterial identification by MALDI-TOF MS and confirmation of clonality by next-generation sequencing—have evolved considerably in the last decade, the intermediate steps of identifying possible outbreak organisms with O and H antigen typing have remained relatively unchanged since the 1940s. This is where novel approaches, such as the mass spectrometric H antigen typing protocol (MS-H)2 presented in this issue of Clinical Chemistry by Cheng and colleagues (2) can complement and update existing workflows for outbreak investigations. MS-H is a qualitative proteomics approach for typing H …

[学科分类] 过敏症与临床免疫学