Wang Tingting, Sun Silu, Xu Yanxing, Waigi Michael Gatheru, Odinga Emmanuel Stephen, Vasilyeva Galina K, Gao Yanzheng, Hu Xiaojie
Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China.
Institute of Physicochemical and Biological Problems in Soil Science, Russian Academy of Sciences, Pushchino, Russia.
Front Microbiol. 2022 Mar 14;13:848750. doi: 10.3389/fmicb.2022.848750. eCollection 2022.
The increasing antibiotic resistance genes (ARGs) in fertilizer-amended soils can potentially enter food chains through their transfer in a soil-vegetable system, thus, posing threats to human health. As nitrogen is an essential nutrient in agricultural production, the effect of nitrogen (in the forms NH -N and NO -N) on the distribution of ARGs (, , and ) and a mobile genetic element (MGE; ) in a soil-Chinese cabbage system was investigated. Not all the tested genes could transfer from soil to vegetable. For transferable ones (, , and ), nitrogen application influenced their abundances in soil and vegetable but did not impact their distribution patterns (i.e., preference to either leaf or root tissues). For ARGs in soil, effects of nitrogen on their abundances varied over time, and the positive effect of NH -N was more significant than that of NO -N. The ARG accumulation to vegetables was affected by nitrogen application, and the nitrogen form was no longer a key influencing factor. In most cases, ARGs were found to prefer being enriched in roots, and nitrogen application may slightly affect their migration from root to leaf. The calculated estimated human intake values indicated that both children and adults could intake 10-10 copies of ARGs per day from Chinese cabbage consumption, and nitrogen application affected ARG intake to varying degrees. These results provided a new understanding of ARG distribution in vegetables under the agronomic measures such as nitrogen application, which may offer knowledge for healthy vegetable cultivation in future.
施肥土壤中日益增加的抗生素抗性基因（ARGs）可能通过在土壤-蔬菜系统中的转移进入食物链，从而对人类健康构成威胁。由于氮是农业生产中的一种必需养分，因此研究了氮（以NH -N和NO -N形式）对土壤-大白菜系统中ARGs（、和）和一种可移动遗传元件（MGE；）分布的影响。并非所有测试基因都能从土壤转移到蔬菜中。对于可转移的基因（、和），施氮影响它们在土壤和蔬菜中的丰度，但不影响它们的分布模式（即对叶或根组织的偏好）。对于土壤中的ARGs，氮对其丰度的影响随时间变化，且NH -N的积极影响比NO -N更显著。ARGs在蔬菜中的积累受施氮影响，且氮形态不再是关键影响因素。在大多数情况下，发现ARGs更喜欢在根中富集，施氮可能会轻微影响它们从根向叶的迁移。计算得出的估计人类摄入量值表明，儿童和成人每天从食用大白菜中可摄入10-10个ARGs拷贝，且施氮对ARGs摄入量有不同程度的影响。这些结果为氮施用等农艺措施下蔬菜中ARGs的分布提供了新的认识，这可能为未来健康蔬菜种植提供知识。
