云南省市售木耳、银耳中唐菖蒲伯克霍尔德氏菌污染调查及毒力基因分析

Investigation of Burkholderia gladioli contamination and analysis of virulence genes in commercially available Auricularia auricula and Tremella fuciformis in Yunnan Province

中文关键词:  木耳  银耳  唐菖蒲伯克霍尔德氏菌  bon基因簇  米酵菌酸  系统发育

英文关键词:Auricularia auricula  Tremella fuciformis  Burkholderia gladioli  bon gene cluster  bongkrekic acid  phylogenetics

中文摘要:

      目的 调查云南省2022—2024年食用菌中唐菖蒲伯克霍尔德氏菌(Burkholderia gladioli)污染状况, 对分离菌株进行全基因组测序, 分析产毒菌株基因特征。方法 从云南省采集样品724份, 对分离鉴定得到的菌株进行二代全基因组测序, 分析其遗传特性、米酵菌酸生物合成相关bon基因簇携带情况。结果 724份样品唐菖蒲伯克霍尔德氏菌检出率为12.85% (93/724), 其中木耳、银耳检出率分别为13.20% (61/462)、12.87% (26/202), 无统计学差异(P>0.05)。该菌的污染有明显的地域差异性(P<0.05), 流通环节检出率无差异(P>0.05)。17份样品中检出携带完整bon基因簇的唐菖蒲伯克霍尔德氏菌椰毒致病变种, 但产毒能力有差异, 发现2株高产毒椰毒致病变种。系统发育分析表明97株分离株分在多支进化树上, 部分木耳和银耳中的分离株有明显的聚类倾向, bon基因簇与核心基因组进化树高度一致。结论 云南省市售木耳、银耳中的唐菖蒲伯克霍尔德氏菌污染有明显地域差异性, 应对高风险地州实施专项食品监测。

英文摘要:

      Objective To investigate the contamination status of Burkholderia gladioli in edible fungi in Yunnan Province from 2022 to 2024, perform whole-genome sequencing on isolated strains, and analyze the genetic characteristics of toxin-producing strains. Methods A total of 724 samples were collected from Yunnan Province. The isolated and identified strains were subjected to second-generation whole-genome sequencing to analyze their genetic characteristics and the presence of bon gene clusters related to bongkrekic acid biosynthesis. Results The detection rate of Burkholderia gladioli in the 724 samples was 12.85% (97/724), the detection rates of Auricularia auricula and Tremella fuciformis were 13.20% (61/462) and 12.87% (26/202) (P>0.05), respectively, with no statistical difference (P<0.05). The contamination of this bacterium had obvious regional differences (P>0.05), and the detection rate in the circulation link had no difference. The 17 samples were found to contain Burkholderia gladioli pathovar cocovenenans carrying complete bon gene clusters, but with varying toxin-producing abilities, 2 highly toxic cocovenenans variants were identified. Phylogenetic analysis showed that the 97 isolates were distributed on multiple branches of the evolutionary tree, with some isolates from Auricularia auricula and Tremella fuciformis showing a clear tendency to cluster. The bon gene clusters were highly consistent with the core genome phylogenetic tree. Conclusion There are significant regional differences in the contamination of Burkholderia gladioli in commercially available Auricularia auricula and Tremella fuciformis across Yunnan Province. Targeted food monitoring shall be implemented in high-risk prefectures.