High prevalence of antibiotic-resistant and metal-tolerant cultivable bacteria in remote glacier environment
High prevalence of antibiotic-resistant and metal-tolerant cultivable bacteria in remote glacier environment
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DOI：
10.1016/j.envres.2023.117444
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发表时间：
2023-10-20
影响因子：
8.3
通讯作者：
Kang，Shichang
中科院分区：
文献类型：
--
作者：
Sajjad，Wasim;Ali，Barkat;Kang，Shichang
耐药菌（ARB）的研究主要来自人类影响的环境，与原始环境的信息有限。偏远的寒冷环境是ARB的主要储存库，并已在极地地区确定;然而，它们在非极地寒冷栖息地的丰度还未得到充分探索。本研究对白水1号冰川碎屑和融水中分离到的38株ARB进行了抗生素和金属耐药谱、抗生素耐药基因（ARG）和金属耐受基因（MTG）的检测。分子鉴定显示变形菌（39.3%）占主导地位的碎片，而融水占主导地位的放线菌（30%）和变形菌（30%）。细菌分离株表现出多个抗生素耐药指数值> 0.2。革兰阴性菌对抗生素和金属的耐药性高于革兰阳性菌。在β-内酰胺类抗生素耐药菌中，CTX-M（21.1-71.1%）、ACC（21.1-60.5%）、四环素耐药菌（21.1 - 60.5%）和磺胺类抗生素耐药菌（18.4-52.6%）的PCR扩增结果显示出明显的ARG。耐汞菌A（21.1-63.2%）、耐铜菌B（18.4-57.9%）、耐铬菌A（15.8-44.7%）和耐砷菌B（10.5-44.7%）。这突出了MTG和ARG在偏远冰川环境中的共同选择和共同出现。不同的细菌具有相同的ARG，这意味着物种之间的水平基因转移。据报告，ARG和MTG之间存在很强的正相关。耐金属范围显示革兰氏阴性菌和革兰氏阳性菌明显聚集。革兰氏阴性菌对重金属有明显的耐受性。blaACC、blaCTX-M、blaSHV、blaampC、qnrA、sulI、tetA和blaTEM的氨基酸序列发生变异。这项研究提出了有前途的ARB，窝藏ARG与氨基酸序列的变化，强调需要评估冰川细菌赋予ARG和MTG的转录组研究。
Studies of antibiotic-resistant bacteria (ARB) have mainly originated from anthropic-influenced environments, with limited information from pristine environments. Remote cold environments are major reservoirs of ARB and have been determined in polar regions; however, their abundance in non-polar cold habitats is underexplored. This study evaluated antibiotics and metals resistance profiles, prevalence of antibiotic resistance genes (ARGs) and metals tolerance genes (MTGs) in 38 ARB isolated from the glacier debris and meltwater from Baishui Glacier No 1, China. Molecular identification displayed Proteobacteria (39.3%) predominant in debris, while meltwater was dominated by Actinobacteria (30%) and Proteobacteria (30%). Bacterial isolates exhibited multiple antibiotic resistance index values > 0.2. Gram-negative bacteria displayed higher resistance to antibiotics and metals than Gram-positive. PCR amplification exhibited distinct ARGs in bacteria dominated by β-lactam genesblaCTX-M(21.1–71.1%),blaACC(21.1–60.5%), tetracycline-resistant genetetA(21.1–60.5%), and sulfonamide-resistant genesulI(18.4–52.6%). Moreover, different MTGs were reported in bacterial isolates, including mercury-resistantmerA(21.1–63.2%), copper-resistantcopB(18.4–57.9%), chromium-resistantchrA(15.8–44.7%) and arsenic-resistantarsB(10.5–44.7%). This highlights the co-selection and co-occurrence of MTGs and ARGs in remote glacier environments. Different bacteria shared same ARGs, signifying horizontal gene transfer between species. Strong positive correlation among ARGs and MTGs was reported. Metals tolerance range exhibited that Gram-negative and Gram-positive bacteria clustered distinctly. Gram-negative bacteria were significantly tolerant to metals. Amino acid sequences ofblaACC,blaCTX-M,blaSHV,blaampC,qnrA,sulI, tetAandblaTEMrevealed variations. This study presents promising ARB, harboring ARGs with variations in amino acid sequences, highlighting the need to assess the transcriptome study of glacier bacteria conferring ARGs and MTGs.