湖北省一起米酵菌酸引起食物中毒事件的调查分析

Investigation and analysis of a food poisoning incident caused by bongkrekic acid in Hubei Province

中文关键词:  唐菖蒲伯克霍尔德氏菌椰毒致病种  米酵菌酸  食物中毒

英文关键词:Burkholderia gladioli  bongkrekic acid  food poisoning

中文摘要:

      目的 调查分析湖北省孝感市一起米酵菌酸(bongkrekic acid, BA)引起的中毒事件, 分离鉴定病原菌, 并检测其毒素。方法 采用超高效液相色谱-串联质谱(ultra performance liquid chromatography-tandem mass spectrometry, UPLC-MS/MS)法测定2份暴露食品(凉皮)、3份食品储存环境样本及2份病例血液样本中BA。参照GB/T 4789.29—2020《食品卫生微生物检验 唐菖蒲伯克霍尔德氏菌(椰毒假单胞菌酵米面亚种)检验》, 对2份暴露食品及3份环境样本中的病原菌进行分离培养、飞行时间质谱、16S rDNA测序、实时荧光定量聚合酶链式反应(polymerase chain reaction, PCR)分析、产毒实验等微生物鉴定。结果 两例病例血液样本中BA质量浓度分别为92.2 μg/L、1059.0 μg/L, 待售凉皮与冻存凉皮中BA含量分别为2.26 mg/kg、0.39 mg/kg, 环境样本均未检出BA。从疑似暴露食品中分离出两株可疑菌株, VITEK MS飞行时间质谱仪及16S rDNA测序比对结果表明两株可疑菌株均为唐菖蒲伯克霍尔德氏菌, 实时荧光定量PCR分析及产毒实验结果表明两株可疑菌株均可产生BA且bon基因阳性, 均具备产毒能力, 综合判定为唐菖蒲伯克霍尔德氏菌椰毒致病种。环境样本中未鉴定出唐菖蒲伯克霍尔德氏菌。结论 本次食物中毒事件由受唐菖蒲伯克霍尔德氏菌椰毒致病种污染的凉皮食品引起, 有关部门需加强食品安全监管, 防范类似中毒事件发生。

英文摘要:

      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.