Aims

To identify the main spoilage bacterium on fresh-cut leafy vegetables and establish a multiplex PCR assay.

Methods and results

Based on physiological-biochemical, molecular identification, and artificial contamination tests, the main bacterium to spoil fresh-cut leafy vegetables was identified as Exiguobacterium spp. and Exiguobacterium acetylicum. Comparative genomics showed that P401_RS0117025 and oxi_50,582,462 genes are specific to Exiguobacterium spp. and E. acetylicum. Based on this, three pairs of primer sets to EaG-291, EaS-2B, and Ea16S-12 genes were designed and used to develop a multiplex PCR assay, which exhibited 100% specificity among 16 Exiguobacterium and 10 non-Exiguobacterium strains. Finally, 84 fresh-cut leafy vegetable samples were analyzed by multiplex PCR assay and standard physiological-biochemical experiments, the results showed multiplex PCR assay reached a detection rate of 96%.

Conclusions

The main spoilage bacterium was identified as Exiguobacterium spp. and E. acetylicum on fresh-cut leafy vegetables based on the novel specific genes explored in this study.

Significance and impact of study

A rapid, specific, and sensitive PCR assay was developed for the detection of Exiguobacterium spp. and E. acetylicum.

中文翻译：

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检测 Exiguobacterium spp。和 E. acetylicum 在鲜切叶菜上的多重 PCR 检测

宗旨

鉴定鲜切叶菜的主要腐败菌并建立多重PCR检测方法。

方法和结果

经生理生化、分子鉴定和人工污染试验，鉴定鲜切叶菜变质的主要细菌为Exiguobacterium spp。和乙酰微小杆菌。比较基因组学表明P401_RS0117025和oxi_50,582,462基因是针对微小杆菌属。和E. acetylicum。在此基础上，设计了 EaG-291、EaS-2B 和 Ea16S-12 基因的三对引物组并用于开发多重 PCR 检测，该检测在 16 种微小杆菌属和 10 种非微小杆菌属中表现出 100% 的特异性。菌株。最后对84份鲜切叶菜样品进行多重PCR检测和标准生理生化实验，结果表明多重PCR检测的检出率达到96%。

结论

主要腐败菌被鉴定为Exiguobacterium spp。和E. acetylicum在基于本研究探索的新特定基因的鲜切叶菜上。

研究的意义和影响

开发了一种快速、特异且灵敏的 PCR 检测方法，用于检测Exiguobacterium spp。和E. acetylicum。