摘要
      抗生素耐药性的传播正在成为一个严重的全球健康问题。已经进行了大量的研究来研究抗生素抗性基因（ARGs）在室内和室外环境中的动力学。尽管如此，很少有关于在外层空间环境中应激下抗生素耐药性（微生物培养物或群落中ARGs的总含量）的动力学的研究。在这项研究中，我们旨在通过对先前产生的宏基因组学数据的分析，对国际空间站外BIOMEX实验期间模拟的暴露于类火星条件下的康普茶共生群落（KMC）样本中ARGs和金属抗性基因（MRG）的动力学进行实验研究。因此，我们将它们与各自未暴露的KMC样本进行了比较。抗生素耐药性组通过在暴露后用ARGs丰富其多样性来应对类火星条件，而在未暴露的样本中没有发现ARGs（即分别针对四环素和万古霉素的tet和van基因）。此外，ARGs和MRGs是相关的；因此，它们的共同选择可以被认为是在类火星环境中维持抗生素耐药性的一种机制。总的来说，这些结果突出了抗生素耐药性在对地外条件和没有人为压力的情况下的高可塑性。
Abstract
The spread of antibiotic resistance is becoming a serious global health concern. Numerous studies have been done to investigate the dynamics of antibiotic resistance genes (ARGs) in both indoor and outdoor environments. Nonetheless, few studies are available about the dynamics of the antibiotic resistome (total content of ARGs in the microbial cultures or communities) under stress in outer space environments. In this study, we aimed to experimentally investigate the dynamics of ARGs and metal resistance genes (MRGs) in Kombucha Mutualistic Community (KMC) samples exposed to Mars-like conditions simulated during the BIOMEX experiment outside the International Space Station with analysis of the metagenomics data previously produced. Thus, we compared them with those of the respective non-exposed KMC samples. The antibiotic resistome responded to the Mars-like conditions by enriching its diversity with ARGs after exposure, which were not found in non-exposed samples (i.e., tet and van genes against tetracycline and vancomycin, respectively). Furthermore, ARGs and MRGs were correlated; therefore, their co-selection could be assumed as a mechanism for maintaining antibiotic resistance in Mars-like environments. Overall, these results highlight the high plasticity of the antibiotic resistome in response to extraterrestrial conditions and in the absence of anthropogenic stresses.

https://www.liebertpub.com/doi/abs/10.1089/ast.2021.0176