Rapid, Sensitive, and Selective Quantification of Spores Using xMAP Technology.

is a spore-forming ubiquitous bacterium notable as a food poisoning agent. Detection of spores using selective media is laborious and non-specific. Herein, the quantitative detection of spores was investigated with commercial antibodies and published aptamer sequences. Several detection reagents were screened for affinity to collagen-like protein A (BclA), an abundant exosporium glycoprotein. Sensitivity and selectivity toward spores were tested using immunoassays and multi-analyte profiling (xMAP). A recombinant antibody developed in llama against BclA protein showed spore selectivity and sensitivity between 10 and 10 spores/mL using xMAP. DNA aptamer sequences demonstrated sensitivity from 10 to 10 spores/mL and no cross-reaction to and . Selectivity for spores was also demonstrated in a mixture of several diverse microorganisms and within a food sample with no compromise of sensitivity. As proof of concept for multiplexed measurement of human pathogens, and three other microorganisms, , and , were simultaneously detected using xMAP. These data support the development of a rapid, sensitive, and selective system for quantitation of spores and multiplexed monitoring of human pathogens in complex matrices.