Objective To investigate and analyze a food poisoning incident caused by bongkrekic acid (BA) in Xiaogan City, Hubei Province, isolate and identify the pathogenic bacteria, and detect the toxin. Methods Ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was used to measure BA levels in 2 exposed food samples (cold rice noodles), 3 food storage environment samples, and 2 patient blood samples. Following GB/T 4789.29—2020 Microbiological examination of food hygiene—Examination of Burkholderia gladioli (Pseudomonas cocovenenans subsp. farinofermentans), microbial identification was performed on 2 exposed food samples and 3 environmental samples, including isolation and culture, matrix-assisted laser desorption/ ionization time-of-flight mass spectrometry, 16S rDNA sequencing, real-time quantitative polymerase chain reaction (PCR) analysis, and toxin production experiments. Results The BA concentrations in the 2 patients’ blood samples were 92.2 μg/L and 1059.0 μg/L, respectively. The BA content in the unsold and frozen cold rice noodles was 2.26 mg/kg and 0.39 mg/kg, respectively, while no BA was detected in the environmental samples. Two suspected strains were isolated from the implicated food. VITEK MS MALDI-TOF MS and 16S rDNA sequencing identified both strains as Burkholderia gladioli. Real-time quantitative PCR and toxin production experiments confirmed that both strains could produce BA and tested positive for the bon gene, indicating toxigenic potential. They were comprehensively identified as Burkholderia gladioli pathovar cocovenenans. No Burkholderia gladioli was detected in the environmental samples. Conclusion This food poisoning incident is caused by cold rice noodles contaminated with Burkholderia gladioli pathovar cocovenenans. Relevant authorities need to strengthen food safety supervision to prevent similar poisoning incidents.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |