摘要
      土壤是微生物多样性的宝库，也是获取和传播抗微生物耐药性的最有利栖息地。耐药性转移通常发生在动物与土壤之间，反之亦然，最终可能出现在临床病原体中。在这项研究中，对沙特阿拉伯西南高地进行了研究，以评估该地区旅游业的持续发展可能影响的细菌多样性和抗微生物耐药性。这种影响可能会对当地环境和社区产生长期影响。使用培养依赖性、定量聚合酶链式反应（qPCR）和基于鸟枪测序的宏基因组方法来评估从收集的土壤样本中分离的细菌的多样性、功能能力和抗微生物耐药性。西南高地的细菌群落主要由变形杆菌、拟杆菌和放线菌组成。在土壤微生物群中共鉴定出102个抗微生物耐药性基因（ARGs）和变异体，主要与多药耐药性有关，其次是大环内酯类、四环素类、糖肽类、杆菌肽类和β-内酰胺类抗生素耐药性。耐药机制包括外排、抗生素靶点改变和抗生素失活。qPCR证实检测到18个临床上重要的ARG。此外，在49个已鉴定的分离株中，有一半对测试的15种抗生素中的至少一种具有表型耐药性。总体而言，ARGs和人类活动的指示基因（人类线粒体[hmt]基因和整合素整合酶[int1]）的丰度相对较低。随着细菌群落的高度多样性，在沙特阿拉伯西南高地的采样点之间，细菌分类群的相对丰度也出现了变化。
Abstract
Soil is a reservoir of microbial diversity and the most supportive habitat for acquiring and transmitting antimicrobial resistance. Resistance transfer usually occurs from animal to soil and vice versa, and it may ultimately appear in clinical pathogens. In this study, the southwestern highlands of Saudi Arabia were studied to assess the bacterial diversity and antimicrobial resistance that could be affected by the continuous development of tourism in the region. Such effects could have a long-lasting impact on the local environment and community. Culture-dependent, quantitative polymerase chain reaction (qPCR), and shotgun sequencing-based metagenomic approaches were used to evaluate the diversity, functional capabilities, and antimicrobial resistance of bacteria isolated from collected soil samples. Bacterial communities in the southwestern highlands were mainly composed of Proteobacteria, Bacteroidetes, and Actinobacteria. A total of 102 antimicrobial resistance genes (ARGs) and variants were identified in the soil microbiota and were mainly associated with multidrug resistance, followed by macrolide, tetracycline, glycopeptide, bacitracin, and beta-lactam antibiotic resistance. The mechanisms of resistance included efflux, antibiotic target alteration, and antibiotic inactivation. qPCR confirmed the detection of 18 clinically important ARGs. In addition, half of the 49 identified isolates were phenotypically resistant to at least one of the 15 antibiotics tested. Overall, ARGs and indicator genes of anthropogenic activities (human-mitochondrial [hmt] gene and integron-integrase [int1]) were found in relatively lower abundance. Along with a high diversity of bacterial communities, variation was observed in the relative abundance of bacterial taxa among sampling sites in the southwestern highlands of Saudi Arabia.

https://www.sciencedirect.com/science/article/pii/S1319562X21010081