许多企鹅可以将具有抗生素抗性基因(ARGs)的病原体传播到南极洲。然而,通过鸟粪沉积,企鹅传播对湖泊ARG的影响仍然很少受到关注。这里,我们已经对来自南极洲16个湖泊的企鹅鸟粪(OLS)和非鸟源性沉积物(NOLS)的鸟源性沉积物中的ARG进行了分析。在所有沉积物样本中共检测到191种ARGs,OLS的丰度和多样性比NOLS高得多。令人惊讶的是,在OLS中发现了高度多样化和丰富的ARG,检测频率>40%,绝对丰度为(2.34×109)-(4.98×109)拷贝g-1,与沿海河口沉积物和养猪场相当。确定的抗性基因与企鹅鸟粪输入量的强相关性,环境因素,移动遗传元素,和细菌群落,结合网络和冗余分析,都表明企鹅是通过鸟粪沉积在湖泊沉积物中传播和高度富集ARGs的原因,这可能会大大超过当地人类活动的影响。我们的研究结果表明,ARGs可以通过企鹅的迁徙进入南极洲的湖泊,食物链,和鸟粪沉积,这与全球范围内广泛的ARGs污染密切相关。
Numerous penguins can propagate pathogens with antibiotic resistance genes (ARGs) into
Antarctica. However, the effects of penguin dissemination on the lake ARGs still have received little attention via guano deposition. Here, we have profiled ARGs in ornithogenic sediments subject to penguin guano (OLS) and nonornithogenic sediments (NOLS) from 16 lakes across
Antarctica. A total of 191 ARGs were detected in all sediment samples, with a much higher abundance and diversity in OLS than in NOLS. Surprisingly, highly diverse and abundant ARGs were found in the OLS with a detection frequency of >40% and an absolute abundance of (2.34 × 109)-(4.98 × 109) copies g-1, comparable to those in coastal estuarine sediments and pig farms. The strong correlations of identified resistance genes with penguin guano input amount, environmental factors, mobile genetic elements, and bacterial community, in conjunction with network and redundancy analyses, all indicated that penguins were responsible for the dissemination and high enrichment of ARGs in lake sediments via the guano deposition, which might greatly outweigh local human-activity effects. Our results revealed that ARGs could be carried into lakes across the
Antarctica through penguin migration, food chains, and guano deposition, which were closely connected with the widespread pollution of ARGs at the global scale.