Again in your capacity working for the DHS, you have just received an urgent call from the CDC to consult on another, unrelated case of an unusual disease outbreak that researchers at the CDC have...

Again in your capacity working for the DHS, you have just received an urgent call from the CDC to consult on another, unrelated case of an unusual disease outbreak that researchers at the CDC have been investigating. The researchers isolated a new grampositive bacterium related to Listeria from an outbreak of food poisoning in Wisconsin due to contaminated cheese that appears to cause painful gastritis and, in about half of exposed individuals, sudden onset of bleeding ulcers, followed by death from toxic shock within 2 to 3 days. Upon biopsy of infected individuals, it was found that the bacteria were growing on the surfaces of epithelial cells lining the gastric pit of the stomach. Autopsy of individuals who died showed that bacteria were present only in the stomach and not in any of the other body organs. The researchers at the CDC have subsequently determined that, unlike L. monocytogenes, this bacterium does not invade epithelial cells or spread from cell to cell. When the researchers grew the bacteria in laboratory medium overnight and then introduced the filtered culture medium onto the surface of the stomach epithelial layer in experimental rabbits, they found that bleeding stomach ulcers were formed and the rabbits died from toxic shock within 1 to 2 days. When they analyzed the filtered culture medium by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, they found that five protein bands were present on the gel. The researchers cut out each of these bands from the gel and subjected the proteins to protease digestion, followed by N-terminal sequencing of the cleaved peptide fragments. When they compared the sequences of the cleaved peptides from each protein with the known protein databases, they found that protein 1 had sequence homology to Helicobacter pylori urease, protein 2 had sequence homology to the mucinases of H. pylori and V. cholerae, protein 3 had sequence homology to the catalytic A subunit of Shiga toxin, protein 4 had sequence homology to anthrax lethal factor, and protein 5 had sequence homology to the protective antigen of anthrax toxin. In your expert opinion as a microbiologist and researcher in the field of bacterial pathogenesis, is there plausible cause for the DHS to be concerned that either one or both of these incidences could be a potential act of bioterrorism? Be sure to state your rationale.