Bongkrekic acid (BKA) is a tricarboxylic fatty acid that inhibits adenine nucleotide translocase as a kind of mitochondrial toxins. BKA is produced by the bacterium Burkholderia gladioli pathovar cocovenenans. An investigation was performed to determine the source of possible BKA poisoning of a family in H City, Guangdong Province, People's Republic of China, who consumed a commercially produced rice noodle product that was not fermented or noticeably spoiled. Clinical and food samples were tested. BKA concentration was detected by liquid chromatography-tandem mass spectrometry. We isolated and identified the suspicious strains from the rice noodles and performed toxicity determination through an animal experiment. BKA detected in the cases and the dead dog was 2.15 to about 343 μg/kg. The cases and dead dog shared a unique history of food exposure. The BKA in the factory's food samples was 150 and 160 μg/kg. All mice given the BKA extract by gavage died within 24 h. In conclusion, the food poisoning was caused by the high BKA concentration of expired (4 days over the 24-h shelf life) wet rice noodle products, with corn and wheat starch contaminated by B. gladioli cocovenenans. Different from traditional BKA poisoning caused by fermented and spoiled corn or coconut products, there was no noticeable spoilage because of the nonfermentation process and overused sodium dehydroacetate. The risk of BKA in wet rice noodle products and application of antiseptics, such as sodium dehydroacetate, in such food should be quantitatively evaluated to prevent the recurrence of similar events.
Keywords: Bongkrekic acid; Burkholderia gladioli pathovar cocovenenans; Fermentation; Sodium dehydroacetate; Spoilage; Wet rice noodle products.