Identification of Bacillus and Yersinia species and hoax agents by protein profiling using microfluidic capillary electrophoresis with peak detection algorithms

Abstract

Bacillus anthracis and Yersinia pestis are biological agents that pose an increasing concern to national security if deliberately disseminated. Hoax agents, including suspicious white powders and environmental bacterial species, can also cause disruption. In either scenario it is of high importance to rapidly and accurately identify any suspicious powder as hazardous or hoax. Protein profiling, using microfluidic capillary electrophoresis, provides a rapid (less than 40 minutes), reliable and field-based screening method. Two commonly encountered hoax agents, three Bacillus species (including B. anthracis Sterne strain), two Yersinia species and E. coli were profiled on the Experion™ System (Bio-Rad). Peak detection algorithms were developed for the identification of protein peaks in electropherograms. Boolean logic paths were then employed to predict the electrophoretic pattern of samples. Parameters assessed included variation within and between Experion™ Pro260 chips and the ability to discriminate between samples over time intervals, between operators and between field and laboratory analyses. Classification with optimal Boolean logic paths reported no misclassification with an accuracy of 100% for B. anthracis Sterne strain, B. thuringiensis (powder and culture-based), B. cereus and plain wheat flour. Overall there was 75% correct identification for the eight sample types tested.