Arcadi Erika, Rastelli Eugenio, Tangherlini Michael, Rizzo Carmen, Mancuso Monique, Sanfilippo Marilena, Esposito Valentina, Andaloro Franco, Romeo Teresa
Department of Integrative Marine Ecology, Stazione Zoologica "Anton Dohrn", Sicily Marine Centre, Contrada Porticatello, 29, 98167 Messina, Italy.
Department of Marine Biotechnology, Stazione Zoologica "Anton Dohrn", Fano Marine Centre, Viale Adriatico 1-N, 61032 Fano, Italy.
Microorganisms. 2022 Feb 21;10(2):479. doi: 10.3390/microorganisms10020479.
Environmental contamination by heavy metals (HMs) poses several indirect risks to human health, including the co-spreading of genetic traits conferring resistance to both HMs and antibiotics among micro-organisms. Microbial antibiotic resistance (AR) acquisition is enhanced at sites anthropogenically polluted by HMs, as well as in remote systems naturally enriched in HMs, such as hydrothermal vents in the deep sea. However, to date, the possible role of hydrothermal vents at shallower water depths as hot spots of microbial AR gain and spreading has not been tested, despite the higher potential risks associated with the closer vicinity of such ecosystems to coasts and human activities. In this work, we collected waters and sediments at the Panarea shallow-water hydrothermal vents, testing the presence of culturable marine bacteria and their sensitivity to antibiotics and HMs. All of the bacterial isolates showed resistance to at least one antibiotic and one HM and, most notably, 80% of them displayed multi-AR on average to 12 (min 8, max 15) different antibiotics, as well as multi-HM tolerance. We show that our isolates displayed high similarity (≥99%) to common marine bacteria, affiliating with Actinobacteria, Gammaproteobacteria, Alphaproteobacteria and Firmicutes, and all displayed wide growth ranges for temperature and salinity during in vitro physiological tests. Notably, the analysis of the genomes available in public databases for their closest relatives highlighted the lack of genes for AR, posing new questions on the origin of multi-AR acquisition in this peculiar HM-rich environment. Overall, our results point out that shallow-water hydrothermal vents may contribute to enhance AR acquisition and spreading among common marine bacteria in coastal areas, highlighting this as a focus for future research.
重金属（HMs）造成的环境污染对人类健康构成了若干间接风险，包括微生物中赋予对HMs和抗生素抗性的遗传性状的共同传播。在人为污染的HMs场所，以及在自然富含HMs的偏远系统中，如深海热液喷口，微生物对抗生素的抗性（AR）获得有所增强。然而，迄今为止，尽管浅水热液喷口这类生态系统距离海岸和人类活动更近，相关潜在风险更高，但尚未测试其作为微生物AR获得和传播热点的可能作用。在这项研究中，我们在帕纳雷阿浅水热液喷口采集了水样和沉积物，检测可培养海洋细菌的存在及其对抗生素和HMs的敏感性。所有细菌分离株均对至少一种抗生素和一种HMs表现出抗性，最值得注意的是，其中80%平均对12种（最少8种，最多15种）不同抗生素表现出多重AR，以及多重HMs耐受性。我们发现，我们的分离株与常见海洋细菌具有高度相似性（≥99%），隶属于放线菌门、γ-变形菌纲、α-变形菌纲和厚壁菌门，并且在体外生理测试中均表现出较宽的温度和盐度生长范围。值得注意的是，对其最接近亲属在公共数据库中可用基因组的分析突出表明缺乏AR基因，这对在这种特殊的富含HMs的环境中多重AR获得的起源提出了新问题。总体而言，我们的结果指出，浅水热液喷口可能有助于增强沿海地区常见海洋细菌中AR的获得和传播，突出表明这是未来研究的一个重点。
