摘要
      抗生素耐药性病原体引起的感染对全世界的人类和动物健康构成了高风险。近年来，环境和野生动物作为抗生素抗性基因（ARGs）的主要来源和宿主，正受到越来越多的研究。关于蜱虫中细菌群落的报道很多，但对它们携带的ARGs知之甚少，野生蜱虫中的细菌和ARGs之间的相关性也仍然未知。在此，分别使用高通量16S rRNA测序和基于智能芯片的高通量定量PCR方法（HT-qPCR）研究了野生蜱种的微生物群落和抗生素耐药性。我们发现野生蜱类的细菌组成是可变的；所有样本的测序读数在门水平上被分配到37个不同的门。优势门是变形菌门，占75.60 ± 10.34%，其次是拟杆菌门，占13.78 ± 占细菌群落总数的11.68%。通过HT-qPCR共鉴定了12个抗生素类和20个可移动遗传元件（MGE）的100个不同的ARG，其中氨基糖苷类、多药类、大环内酯类、斜拉米德链脲菌素B和四环素抗性基因是主要的ARG类型。网络分析揭示的共现模式表明，八个细菌属可能是不同ARG的潜在宿主。这项研究首次全面概述了野生蜱体内ARG的多样性和丰度，并强调了野生蜱作为ARG传播者进入环境和脊椎动物宿主的可能作用，对人类和动物健康有影响。
ABSTRACT
Infections caused by antibiotic-resistant pathogens pose high risks to human and animal health worldwide. In recent years, the environment and wildlife as major sources and reservoirs of antibiotic resistance genes (ARGs) are being increasingly investigated. There have been many reports on bacterial community in ticks, but little is known about ARGs they carry, and the correlation between bacterial and ARGs in wild ticks also remains unknown. Here, the profiles of microbial community and antibiotic resistome in wild tick species were investigated using high-throughput 16S rRNA sequencing and smart chip-based high-throughput quantitative PCR approach (HT-qPCR), respectively. We found that bacterial composition in wild tick species is variable; the sequenced reads from all samples were assigned to 37 different phyla at the phylum level. The dominant phylum was Proteobacteria, which accounted for 75.60 ± 10.34%, followed by Bacteroidetes accounting for 13.78 ± 11.68% of the total bacterial community. In total, 100 different ARGs across 12 antibiotic classes and 20 mobile genetic elements (MGEs) were identified by HT-qPCR, and among them aminoglycosides, multidrug, macrolide-clinolamide-streptogramin B, and tetracycline resistance genes were the dominant ARG types. Co-occurrence patterns revealed by network analysis showed that eight bacterial genera may serve as the potential hosts for different ARGs. For the first time, this study provides comprehensive overview of the diversity and abundance of ARGs in wild ticks and highlights the possible role of wild ticks as ARG disseminators into the environment and vertebrate hosts, with implications for human and animal health.

https://journals.asm.org/doi/full/10.1128/msystems.00037-22