Contamination investigation and pathogenic characteristics analysis of Burkholderia gladioli pv. cocovenenans

ObjectiveTo investigate the contamination levels of foods such as woodear， Tremella fuciformis （white jelly fungus）， and rice noodles caused by Burkholderia gladioli pv. cocovenenans， and to elucidate the pathogenic traits of the isolated Burkholderia cocovenenans strains.MethodsAccording to GB 4789.29—2020， a total of 650 samples from seven different food types were collected. Real-time fluorescent quantitative PCR was used to detect the bon gene cluster， while bongkrekic acid levels were measured according to GB 5009.189—2016. Genomic sequencing was performed to elucidate the pathogenic features of Burkholderia cocovenenans.ResultsAmong the 650 samples， 26 strains of Burkholderia cocovenenans were detected， with 22 of these strains isolated from woodear， resulting in a positive detection rate of 15.71%. All strains of Burkholderia cocovenenans harbored the bon and tox gene cluster. The antibiotic resistance analysis revealed that all the strains carry the three antibiotic resistance genes： ceoA， ceoB， and opcM. Phylogenetic analysis indicated that the strains isolated in this experiment belong to the same evolutionary clade as Burkholderia gladioli pv. cocovenenans in the NCBI database， and no significant mutations were observed. Each genome contained between 167 and 184 genes involved in carbohydrate metabolism， with comprehensive metabolic pathways for various polysaccharides， including cellulose， chitin， and starch.ConclusionWoodear are susceptible to contamination by Burkholderia gladioli pv. cocovenenans， which underscores the need for enhanced risk monitoring of this pathogenic bacterium， particularly in woodear.