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.
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.
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.
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.
| 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 |