摘要

    即食沙拉含有可能携带各种抗生素抗性基因（ARG）的微生物。然而，很少有研究集中在沙拉上ARG的流行，因此低估了ARG从沙拉转移到消费者的风险。在这项小型研究中，使用高通量定量PCR来研究与从两种餐厅类型（快餐连锁店和独立休闲餐厅）采购的色拉有关的ARG的存在，流行和丰富。在所评估的色拉产品上总共检测到156种独特的ARG和9种移动遗传元素（MGE）。独立快餐店的ARGs和MGEs的含量显着高于快餐连锁店。在快餐店和休闲餐厅，每克沙拉的ARG绝对拷贝数分别为1.34×107至2.71×108和1.90×108至4.87×108拷贝。从色拉样品中检出的主要细菌菌群是细菌杆菌，拟杆菌，放线菌和硬毛菌。假单胞菌，不动杆菌，Exiguobacterium，Weissella，肠杆菌，Leuconostoc，Pantoea，Serratia，Erwinia和Ewingella是色拉样品中发现的10个最主要的细菌属。检测到ARG和MGE之间存在显着的正相关。这些结果整合了即食沙拉中有关ARGs的知识，并强调了ARGs转移给消费者的潜在影响。

    Ready-to-eat salad harbors microorganisms that may carry various antibiotic resistance genes (ARGs). However, few studies have focused on the prevalence of ARGs on salad, thus underestimating the risk of ARGs transferring from salad to consumers. In this small-scale study, high-throughput quantitative PCR was used to explore the presence, prevalence and abundance of ARGs associated with serving salad sourced from two restaurant types, fast-food chain and independent casual dining. A total of 156 unique ARGs and nine mobile genetic elements (MGEs) were detected on the salad items assessed. The abundance of ARGs and MGEs were significantly higher in independent casual dining than fast-food chain restaurants. Absolute copies of ARGs in salad were 1.34 × 107 to 2.71 × 108 and 1.90 × 108 to 4.87 × 108 copies per g salad in fast-food and casual dining restaurants, respectively. Proteobacteria, Bacteroidetes, Actinobacteria, and Firmicutes were the dominant bacterial phyla detected from salad samples. Pseudomonas, Acinetobacter, Exiguobacterium, Weissella, Enterobacter, Leuconostoc, Pantoea, Serratia, Erwinia, and Ewingella were the 10 most dominant bacterial genera found in salad samples. A significant positive correlation between ARGs and MGEs was detected. These results integrate knowledge about the ARGs in ready-to-eat salad and highlight the potential impact of ARGs transfer to consumers.

    https://www.frontiersin.org/articles/10.3389/fpubh.2020.00092/full?report=reader