The effects of environmental metals on the spread of antimicrobial resistance genes in the stickleback skin microbiome

抗菌素耐药性(AMR)是对人类、动物和我们的环境的一大威胁。虽然这常常与人类和牲畜为主的环境中滥用和过度使用抗生素有关，但它在更广泛的环境中发生的情况却鲜为人知。新的证据表明，AMR基因(ARGs)经常在共生生物体中被发现，例如宿主相关和环境微生物群的成员。这构成了一个重大风险，因为共生耐药生物可能成为耐药基因的储存库，这些基因可能在未来水平转移到病原体或导致机会性感染。为了有效地对抗AMR，我们需要了解环境变化(例如，pH和温度)如何鼓励ARGs在细菌之间传播(即水平基因转移(HGT))。已有研究表明，对金属(如铜、锌、铅等)的抗性。和AMR通常是细菌基因组中的共同选择，并与环境金属水平直接相关(Pal C等人。2017 ADV Micro Physio)。三刺刺鱼是一种研究广泛的模式生物，原产于北部淡水和海洋水域。虽然各种环境因素与它们肠道微生物群的组成有关(Rennison等人)。2019年PREC Royal Soc B)，皮肤微生物群仍未得到充分研究。鱼的皮肤是与环境直接接触的一种粘液膜，是预防感染的重要机制，是微生物组研究的理想对象(Reverter等人，2018年Fish Sahul)。该项目调查苏格兰北乌伊斯特岛金属浓度的环境变化是否导致刺鱼皮肤微生物群中ARGs的存在、丰富和传播(通过HGT)。为了实现该项目的目标，我们将：a.对皮肤微生物群(和周围的水)进行测序，以确定背景细菌污染(Krotman等人。2020个微生物组)，并解释了基因/环境差异b。微生物组的培养和AMR细菌的图谱。此外，在诺丁汉水族馆，将研究从低金属环境和高金属环境中用皮肤微生物群定植具有灵知生物(即无细菌)的鱼，并纵向采样皮肤微生物群以识别新的HGT事件。这项研究将提供有价值的洞察，了解环境变化如何为ARGs的转移提供有利条件，并提供有效的策略来对抗抗生素耐药性。

Antimicrobial resistance (AMR) is a major threat to humans, animals, and our environment. Although this is often associated with the misuse and overuse of antibiotics in human and livestock-dominated environments, its wider environmental occurrence is poorly understood. Emerging evidence suggests that AMR genes (ARGs) are frequently identified in commensal organisms, such as members of host-associated and environmental microbiomes. This poses a major risk as commensal-resistant organisms might serve as a reservoir of resistance genes that can be horizontally transferred to pathogens or cause opportunistic infections in the future. To effectively combat AMR, we need to understand how environmental variation (e.g., pH and temperature) encourages the spread of ARGs between bacteria (i.e., horizontal gene transfer (HGT). It has been shown that resistance to metals (e.g., copper, zinc, lead, etc.) and AMR are often co-selected in bacterial genomes and directly correlate with environmental metal levels (Pal C et al. 2017 Adv Micro Physio). The three-spined stickleback is a well-studied model organism native to fresh and oceanic northern waters. While a variety of environmental factors have been associated with the composition of their gut microbiome (Rennison et al. 2019 Proc Royal Soc B), the skin microbiome remains under-explored. The skin of fish, a mucus membrane in direct contact with the environment, is an important mechanism in infection prevention and ideal for microbiome study (Reverter et al., 2018 Fish Sahul).This project investigates whether environmental variation in metal concentrations on the island of North Uist, Scotland, leads to increased presence, abundance, and spread (via HGT) of ARGs in stickleback skin microbiomes. To address the objective of the project, we will:a. Sequence the skin microbiome (and the surrounding water to determine background bacterial contamination (Krotman et al. 2020 Microbiome)) of stickleback populations, and account for genotype/environmental differencesb. Culture the microbiome and profile AMR bacteriac. Also, in the Nottingham aquariums, colonize gnotobiotic (i.e., germ-free) fish with a skin microbiome from low- vs. high-metal environments will be studied, and longitudinally sample the skin microbiome to identify new HGT events.The study will provide valuable insight into how environmental variations can provide favourable conditions for the transfer of ARGs and offer effective strategies to combat antibiotic resistance.