While municipal solid waste (MSW) provides an ideal habitat for pathogen propagation, the dynamics and assembly of airborne pathogen communities in these environments remain largely unknown. Here, we combined amplicon and metagenomics with spatiotemporal sampling to study inhalable particulate matter-carried potential pathogenic bacteria at full-scale food waste treatment plants (FWTPs), alongside comparisons to urban air in the area. The results showed that pathogenic bacteria constituted a notable portion (64.5 % ± 20.6 %, n = 75) of the total bacterial communities in FWTPs-impacted air, with species and relative abundance 2–4 times higher than that of urban air, and contributed over 50 % of pathogens to the outdoor air. Airborne pathogen community structures were highly shaped by sampling sites (i.e. treatment units), but conserved across seasons (summer vs. winter) and particle sizes (PM_2.5 vs. PM₁₀). Notably, Acinetobacter johnsonii-dominated pathogens (i.e. biofilm-related species) presented high levels of aerosolization and consistently occupied the upper-representative niches in all neutral models, highlighting their persistent exposure risk. Furthermore, pathogen community assembly was strongly driven by stochastic processes (58.8 %-96.8 %), while environmental variables explained only limited variations (3.4 %-28.7 %). In particular, the relative importance of stochastic processes clearly increased along an outdoor-to-indoor gradient (84.9 %-96.5 % vs. 76 %-71.3 %), which might be related to indoor anthropogenic activities that weaken microbial network stability and environmental filtering effects. This work enhances our knowledge of the dynamic behaviors and risk of airborne pathogen communities in MSW disposal and underscores the role of FWTPs in disseminating airborne pathogens.

中文翻译：

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城市餐厨垃圾处理系统中空气传播病原体群落的动态和组装模式及其风险影响


虽然城市固体废物 （MSW） 为病原体的繁殖提供了理想的栖息地，但这些环境中空气传播病原体群落的动态和组装在很大程度上仍然是未知的。在这里，我们将扩增子和宏基因组学与时空采样相结合，以研究全面食物垃圾处理厂 （FWTP） 中携带可吸入颗粒物的潜在致病菌，并与该地区的城市空气进行比较。结果表明，病原菌在受 FWTPs 影响的空气中占细菌群落总数的显着部分 （64.5 % ± 20.6 %，n = 75），物种和相对丰度比城市空气高 2-4 倍，并且贡献了超过 50% 的病原体到室外空气。空气传播的病原体群落结构受采样地点（即处理单位）的高度影响，但在季节（夏季与冬季）和颗粒大小（PM_2.5与 PM₁₀）之间保持不变。值得注意的是，约翰逊不动杆菌主导的病原体（即生物膜相关物种）呈现出高水平的气溶胶化，并在所有中性模型中始终占据上部代表性生态位，突出了它们持续的暴露风险。此外，病原体群落组装受随机过程 （58.8 %-96.8 %） 的强烈驱动，而环境变量仅解释有限的变异 （3.4 %-28.7 %）。特别是，随机过程的相对重要性沿室外到室内梯度明显增加 （84.9 %-96.5 % vs. 76 %-71.3 %），这可能与室内人为活动有关，这些活动削弱了微生物网络的稳定性和环境过滤效应。 这项工作增强了我们对 MSW 处置中空气传播病原体群落的动态行为和风险的了解，并强调了 FWTP 在传播空气传播病原体中的作用。