Irrigation water is well known as potential source of pathogens in fresh produce. However, its role in transferring antibiotic resistance determinants is less well investigated. Therefore, we analyzed the contribution of surface and tap water to the resistome of overhead-irrigated chive plants. Field-grown chive was irrigated with either surface water (R-system) or tap water (D-system), from planting to harvest. Water along the two irrigation chains as well as the respective plants were repeatedly sampled and screened for 264 antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs), using high-capacity qPCR. Differentially abundant (DA) ARGs were determined by comparing the two systems. On R-chive, β-lactam ARGs, multidrug-resistance (MDR) determinants, and MGEs were most abundant, while D-chive featured DA ARGs from the vancomycin class. Diversity and number of DA ARGs was the highest on young chives, strongly diminished at harvest, and increased again at the end of shelf life. Most ARGs highly enriched on R- compared to D-chive were also enriched in R- compared to D-sprinkler water, indicating that water played a major role in ARG enrichment. Of note, bla_KPC was detected at high levels in surface water and chive. We conclude that water quality significantly affects the resistome of the irrigated produce.

中文翻译：

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沿着灌溉水链追踪抗生素抗性基因到韭菜：自来水或地表水有区别吗？

众所周知，灌溉水是新鲜农产品中病原体的潜在来源。然而，其在转移抗生素耐药性决定因素中的作用尚不清楚。因此，我们分析了地表水和自来水对高架灌溉香葱植物抗性的贡献。从种植到收获，田间种植的细香葱均使用地表水（R 系统）或自来水（D 系统）进行灌溉。使用高容量 qPCR 对两条灌溉链沿线的水以及各自的植物进行了重复采样并筛选 264 个抗生素抗性基因 (ARG) 和移动遗传元件 (MGE)。通过比较两个系统来确定差异丰度 (DA) ARG。在 R-chive 上，β-内酰胺 ARG、多药耐药 (MDR) 决定簇和 MGE 最丰富，而 D-chive 则以万古霉素类的 DA ARG 为特色。DA ARG 的多样性和数量在幼韭中最高，在收获时急剧减少，并在保质期结束时再次增加。与 D-细香葱相比，大多数在 R- 上高度富集的 ARG 在 R- 中也比 D-洒水器中富集，这表明水在 ARG 富集中发挥了主要作用。值得注意的是，地表水和细香葱中检测到高含量的bla _{KPC 。}我们得出的结论是，水质显着影响灌溉产品的抗性。