摘要
      抗生素耐药性基因（ARG）是一种生物污染物，由于人类活动的增加而在全球范围内分布。由于全球变暖，冰冻圈中的ARGs越来越受到关注，预计冰川中的ARG将在冰川融化期间释放到下游生态系统中。在本研究中，对来自21个西藏冰川的85个样本的ARG分布及其影响因素进行了调查，这些样本覆盖了雪、冰和冰锥岩栖息地。结果显示，在西藏冰川中，抗29种抗生素的ARGs主要是四环素、杆菌肽、大环内酯和氟喹诺酮耐药性。雪中的ARGs表现出受大气环流影响的生物地理学模式。具体而言，季风主导的冰川比西风主导的冰川表现出更高的ARGs丰度，这可能与印度次大陆更高的抗生素使用量有关。在获得的3241个宏基因组组装基因组中，36.8%被鉴定为ARG宿主，33.8%具有多重耐药性。此外，90个ARGs与可移动遗传元件（MGE）相连。在45个携带ARGs和MGE的MAG中，分别有90.9%和9.1%的MGE被鉴定为质粒和噬菌体。我们的研究表明，以季风为主的冰川释放ARGs的风险更大，这些冰川以高速融化，因此需要仔细监测。
Abstract
Antibiotic-resistance gene (ARG) is a biological pollutant and is globally distributed due to increased anthropogenic activities. ARGs in the cryosphere have received increased attention due to global warming, and ARGs in glaciers are predicted to be released into downstream ecosystems during glacier melting. In this study, ARG distribution and influential factors were investigated in 85 samples from 21 Tibetan glaciers, covering snow, ice, and cryoconite habitats. The results revealed ARGs against 29 antibiotics in Tibetan glaciers, dominated by tetracycline, bacitracin, macrolide, and fluoroquinolone resistance. ARGs in snow exhibited biogeographic patterns influenced by atmospheric circulation. Specifically, monsoon-dominated glaciers exhibited a significantly higher abundance of ARGs than the westerly-dominated glaciers, which could be associated with higher antibiotic usage in the Indian subcontinent. Of the 3241 metagenome-assembled genomes obtained, 36.8% of which were identified as ARG hosts and 33.8% were multidrug-resistant. In addition, 90 ARGs were linked to mobile genetic elements (MGEs). 90.9% and 9.1% of MGEs were identified as plasmid and phage in 45 MAGs carrying both ARGs and MGEs. Our study suggests a greater risk of ARGs being released from the monsoon-dominated glaciers, which were the glaciers that melt at high rates and thus need to be carefully monitored.

https://www.sciencedirect.com/science/article/abs/pii/S0269749122020243