State Key Lab of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
State Key Lab of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
Sci Total Environ. 2022 Apr 1;815:152851. doi: 10.1016/j.scitotenv.2021.152851. Epub 2022 Jan 4.
Fresh vegetables are considered as a reservoir of pathogenic bacteria and antibiotic resistance genes (ARGs), which are the emerging environmental contaminants, posing increasing concerned risk to human health. However, the prevalence of pathogens in phyllosphere of fresh vegetables, as well as the association of ARGs with pathogenic bacteria, have not been well elaborated. In this study, we explored the structure of microbial communities and ARGs through high-throughput quantitative PCR and 16S rRNA gene Illumina sequencing, and characterized the microorganisms resisting to antibiotics by pure culture. From phyllosphere of six different kinds of vegetables, 205 ARGs were detected and genes for multidrug resistance was the most abundant. The predominant potential pathogens were classified to Pseudomonas, Klebsiella, and Acinetobacter genera, which carried various ARGs such as multidrug and beta-lactam resistance genes presumedly. Among six kinds of vegetables, Lactuca sativa var. asparagina carried the highest abundance of potential pathogens and ARGs, while Allium sativum L harbored the lowest abundance of pathogens and ARGs. In addition, various culturable bacteria resisting to colistin or meropenem could be isolated from all vegetables, remarkably, all the isolates resistant to both antibiotics are potential pathogens. Our study highlighted the risks of pathogens and ARGs from raw vegetables to consumers, characterized their structure patterns among different vegetables, and analyzed the potential mechanisms regulating phyllosphere pathogens and resistome of fresh vegetables, which would be helpful for reducing the microbial risk from vegetable ingestion.
新鲜蔬菜被认为是病原菌和抗生素耐药基因（ARGs）的储存库，这些都是新兴的环境污染物，对人类健康构成了越来越大的风险。然而，叶际新鲜蔬菜中病原菌的流行情况，以及 ARGs 与病原菌的关联，尚未得到充分阐述。在本研究中，我们通过高通量定量 PCR 和 16S rRNA 基因 Illumina 测序探索了微生物群落和 ARGs 的结构，并通过纯培养鉴定了对抗生素有抗性的微生物。从 6 种不同蔬菜的叶际中，检测到 205 个 ARGs，其中多药耐药基因最为丰富。主要的潜在病原菌分为假单胞菌、克雷伯氏菌和不动杆菌属，它们可能携带各种 ARGs，如多药和β-内酰胺类耐药基因。在 6 种蔬菜中，生菜携带的潜在病原菌和 ARGs 丰度最高，而大蒜携带的病原菌和 ARGs 丰度最低。此外，从所有蔬菜中均可分离出对黏菌素或美罗培南有抗性的各种可培养细菌，值得注意的是，所有同时耐受这两种抗生素的分离株都是潜在的病原菌。本研究强调了生食蔬菜中病原菌和 ARGs 对消费者的风险，描述了它们在不同蔬菜之间的结构模式，并分析了调节叶际病原菌和新鲜蔬菜抗性组的潜在机制，这有助于降低蔬菜摄入的微生物风险。
