"Cultures" are a brand of traditional probiotic foods, popular on Venus, Luna and Mars. They are small cookies of edible plastic, shaped like petri dishes, filled with sauerkraut, kefir, miso, yogurt or soft cheeses. The probiotic nature of the filling means that they cannot be preserved as long as most foods; they are usually sold from vending machines maintaining vats of slowly fermenting bacteria, filling the cookies as ordered.
Plot Hook: Cultures vending machines are a good vector for bacterial infection. An unknown person or persons has inoculated a kefir vat with a retrovirus causing the bacteria to excrete the fear-instilling toxin flight. Authorities have treated those effected, destroyed the vending machine and dismissed the act as Autonomist art-sabotage. Firewall, however, believes this was a dry run for a larger, much more lethal attack.