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Rapid O serogroup identification of the six clinically relevant Shiga toxin-producing Escherichia coli by antibody microarray

Narasimha V. Hegde, Craig Praul, Andrew Gehring, Pina Fratamico, Chitrita DebRoy
Journal of microbiological methods 2013 v.93 no.3 pp. 273-276
Food Safety and Inspection Service, Shiga toxin-producing Escherichia coli, antibodies, bacterial contamination, detection limit, food contamination, ground beef, pathogen identification, public health, screening, serotypes
An antibody microarray was developed to detect the “top six” non-O157 serogroups, O26, O45, O103, O111, O121, and O145 of Shiga toxin-producing Escherichia coli (STEC), that have been declared as adulterant in meat by the Food Safety and Inspection Service of the United States Department of Agriculture. The sensitivity of the array was 105 CFU and the limit of detection of each serogroup in artificially inoculated ground beef was 1–10 CFU following 12 h of enrichment. Optimal concentrations of antibodies for printing and labeling and bacterial dilutions for binding to the antibodies were assessed. The array utilized a minimal amount of antibodies and other reagents and may be utilized for screening of multiple target O groups of STEC in parallel, directly from enriched samples in less than 3 h. Furthermore, the antibody array provides the flexibility to include other O serogroups of E. coli and may be adopted for high throughput screening. The method is potentially applicable to detect the pathogenic STEC O groups of E. coli in meat and other food, thus improving food safety and public health.