National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China; Department of Clinical Laboratory, Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China.
National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China; Department of Clinical Laboratory, Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China.
Environ Res. 2023 Jul 1;228:115866. doi: 10.1016/j.envres.2023.115866. Epub 2023 Apr 8.
Hospital wastewater contains large amounts of antibiotic-resistant bacteria and serves as an important reservoir for horizontal gene transfer (HGT). However, the response of the microbiome in hospital wastewater to silver remains unclear. In this study, the short-term impacts of silver on the microbiome in hospital wastewater were investigated by metagenome next-generation sequencing. The influence of silver on the conjugation of plasmid carrying bla was further examined. Our results showed that in hospital wastewater, high abundances of antibiotic resistance genes (ARGs) were detected. The distribution tendencies of certain ARG types on chromosomes or plasmids were different. Clinically important ARGs were identified in phage-like contigs, indicating potential transmission via transduction. Pseudomonadales, Enterobacterales, and Bacteroidales were the major ARG hosts. Mobile genetic elements were mainly detected in plasmids and associated with various types of ARGs. The binning approach identified 29 bins that were assigned to three phyla. Various ARGs and virulence factors were identified in 14 and 11 bins, respectively. MetaCHIP identified 49 HGT events. The transferred genes were annotated as ARGs, mobile genetic elements, and functional genes, and they mainly originated from donors belonging to Bacteroides and Pseudomonadales. In addition, 20 nm AgNPs reduced microbial diversity and enhanced the relative abundance of Acinetobacter. The changes induced by 20 nm AgNPs included increases in the abundances of ARGs and genes involved lipid metabolism pathway. Conjugation experiments showed that Ag and 20 nm AgNPs caused 2.38-, 3.31-, 4.72-, and 4.57-fold and 1.46-, 1.61-, 3.86-, and 2.16-fold increases in conjugation frequencies of plasmid with bla at 0.1, 1, 10, and 100 μg/L, respectively. Our findings provide insight into the response of the microbiome in hospital wastewater to silver, emphasize the adaptation capability of Acinetobacter inhabiting hospitals against adverse environments, and highlight the promotion of silver for antibiotic resistance.
医院废水含有大量的抗生素耐药菌，是水平基因转移（HGT）的重要储存库。然而，银对医院废水中微生物组的响应仍不清楚。在这项研究中，通过宏基因组下一代测序研究了银对医院废水中微生物组的短期影响。进一步研究了银对携带 bla 质粒接合的影响。结果表明，在医院废水中，检测到大量抗生素耐药基因（ARGs）。某些 ARG 类型在染色体或质粒上的分布趋势不同。在噬菌体样拼接体中发现了临床重要的 ARG，表明通过转导潜在传播。假单胞菌目、肠杆菌目和拟杆菌目是主要的 ARG 宿主。移动遗传元件主要在质粒中检测到，并与各种类型的 ARGs 相关。分箱方法鉴定出 29 个分箱，它们被分配到三个门。在 14 个和 11 个分箱中分别鉴定出各种 ARGs 和毒力因子。MetaCHIP 鉴定出 49 个 HGT 事件。转移基因被注释为 ARGs、移动遗传元件和功能基因，它们主要来源于拟杆菌属和假单胞菌属的供体。此外，20nm AgNPs 降低了微生物多样性并增加了不动杆菌的相对丰度。20nm AgNPs 引起的变化包括 ARGs 和参与脂质代谢途径的基因丰度增加。接合实验表明，Ag 和 20nm AgNPs 分别在 0.1、1、10 和 100μg/L 时使bla 质粒的接合频率增加了 2.38、3.31、4.72 和 4.57 倍和 1.46、1.61、3.86 和 2.16 倍。本研究结果深入了解了银对医院废水中微生物组的响应，强调了医院中不动杆菌属适应不利环境的适应能力，并突出了银对抗生素耐药性的促进作用。
