摘要
出身背景
抗微生物耐药性（AMR）对人类健康的威胁在全球范围内呈上升趋势。空气中的细颗粒物（PM2.5），尤其是医院排放的细颗粒物质，可能是可吸入抗生素耐药性的一种重要但鲜为人知的环境介质。需要以基因组为中心了解宿主细菌分类群、迁移潜力和耐药体的相应风险，以从临床环境中揭示PM2.5相关AMR的健康相关性。
后果
与城市环境空气PM2.5相比，医院样本中的抗生素耐药性基因（ARGs，~0.2 log10（ARGs/16S rRNA基因））丰度几乎是夏季和冬季样本的两倍。所描述的耐药组与受人类来源影响（约占贡献的30%）的细菌群落密切相关（Procrustes检验，P<0.001），反映了潜在的抗生素耐药性细菌（PARB），如人类共生葡萄球菌和棒状杆菌。尽管从夏季到冬季，组装的宏基因组的丰度和多样性降低，ARGs，如临床相关的blaOXA和bacA，在人类毒性PARB中的高水平转移潜力在医院空气PM样本中未受影响。所研究的PM2.5排放医院中β-内酰胺耐药基因及其宿主基因组的发生模式与病房内β-内胺耐药感染密切相关（SEM，std=0.62，P<0.01）。具有更丰富的潜在毒性PARB（2.89个基因组拷贝/m3空气），医院样本的耐药性风险指数得分明显高于城市环境空气样本，这表明人类通过吸入PM2.5每天暴露于毒性PARB的程度是摄入饮用水的十倍。
结论
ARG的丰度更高、潜在毒性PARB的流行以及与医院病房内β-内酰胺感染的密切关联，突显了AMR在所研究的医院排放PM2.5中的重要性。需要对基因组解析的抗生素耐药性进行更大规模的多源比较，以提供更全面的理解，从“一个健康”的角度评估空气中AMR的重要性。
Abstract
Background
Threats of antimicrobial resistance (AMR) to human health are on the rise worldwide. Airborne fine particulate matter (PM2.5), especially those emitted from hospitals, could serve as a substantial yet lesser-known environmental medium of inhalable antibiotic resistomes. A genome-centric understanding of the hosting bacterial taxa, mobility potential, and consequent risks of the resistomes is needed to reveal the health relevance of PM2.5-associated AMR from clinical settings.

Results
Compared to urban ambient air PM2.5, the hospital samples harbored nearly twice the abundance of antibiotic resistantance genes (ARGs, ~ 0.2 log10(ARGs/16S rRNA gene)) in the summer and winter sampled. The profiled resistome was closely correlated with the human-source-influenced (~ 30% of the contribution) bacterial community (Procrustes test, P < 0.001), reflecting the potential antibiotic-resistant bacteria (PARB), such as the human commensals Staphylococcus spp. and Corynebacterium spp. Despite the reduced abundance and diversity of the assembled metagenomes from summer to winter, the high horizontal transfer potential of ARGs, such as the clinically relevant blaOXA and bacA, in the human virulent PARB remained unaffected in the hospital air PM samples. The occurring patterns of β-lactam resistance genes and their hosting genomes in the studied hospital-emitting PM2.5 were closely related to the in-ward β-lactam-resistant infections (SEM, std = 0.62, P < 0.01). Featured with more abundant potentially virulent PARB (2.89 genome copies/m3-air), the hospital samples had significantly higher resistome risk index scores than the urban ambient air samples, indicating that daily human exposure to virulent PARB via the inhalation of PM2.5 was ten times greater than from the ingestion of drinking water.

Conclusions
The significance of AMR in the studied hospital-emitting PM2.5 was highlighted by the greater abundance of ARGs, the prevalence of potentially virulent PARB, and the close association with hospital in-ward β-lactam infections. A larger-scale multi-source comparison of genome-resolved antibiotic resistomes is needed to provide a more holistic understanding to evaluate the importance of airborne AMR from the “One-Health” perspective.

https://link.springer.com/article/10.1186/s40168-021-01197-5