Department of Agriculture, Food and Environmental Sciences, Università Politecnica Delle Marche, Via Brecce Bianche 10, 60131, Ancona, Italy.
USDA-ARS, Poultry Production and Product Safety Research Unit, 1260 W. Maple St, Fayetteville, AR, 72701, USA.
Environ Res. 2021 Jun;197:111011. doi: 10.1016/j.envres.2021.111011. Epub 2021 Mar 24.
Cattle manure and poultry litter are widely used as fertilizers as they are excellent sources of nutrients; however, potential adverse environmental effects exist during land applications, due to the release of zoonotic bacteria and antimicrobial resistance (AMR) genes. This study was conducted to understand linkages between physiochemical composition, bacterial diversity, and AMR gene presence of cattle manure and poultry litter using quantitative polymerase chain reaction to enumerate four AMR genes (ermB, sulI, intlI, and bla), Illumina sequencing of the 16 S region, and analysis of physical and chemical properties. Principal coordinate analysis of Bray-Curtis distance revealed distinct bacterial community structures between the two manure sources. Greater alpha diversity occurred in cattle manure compared to poultry litter (P < 0.05). Redundancy analysis showed a strong relationship between manure physiochemical and composition and bacterial abundance, with positive relationships occurring among electrical conductivity and carbon/nitrogen, and negative associations for total solids and soluble fractions of heavy metals. Cattle manure exhibited greater abundance of macrolide (ermB) and sulfonamide (sulI) resistant genes. Consequently, fresh cattle manure applications may result in greater potential spread of AMR genes to the soil-water environment (relative to poultry litter) and novel best management strategies (such as composting) may reduce the release of AMR genes to the soil-water environment.
牛粪和家禽粪便被广泛用作肥料，因为它们是营养物质的极好来源；然而，在土地应用过程中，由于人畜共患病细菌和抗微生物药物耐药性（AMR）基因的释放，存在潜在的不利环境影响。本研究旨在通过定量聚合酶链反应来了解牛粪和家禽粪便的理化组成、细菌多样性和 AMR 基因存在之间的联系，使用定量聚合酶链反应来计数四个 AMR 基因（ermB、sulI、intlI 和 bla），16S 区的 Illumina 测序，以及物理和化学性质分析。Bray-Curtis 距离的主坐标分析显示出两种粪便来源之间存在明显不同的细菌群落结构。与家禽粪便相比，牛粪中存在更大的 alpha 多样性（P<0.05）。冗余分析表明，粪便理化组成与细菌丰度之间存在很强的关系，电导率和碳/氮之间呈正相关，总固体和重金属可溶部分之间呈负相关。牛粪中表现出更高水平的大环内酯（ermB）和磺胺类（sulI）耐药基因。因此，新鲜牛粪的应用可能会导致 AMR 基因更有可能传播到土壤-水环境（相对于家禽粪便），而新的最佳管理策略（如堆肥）可能会减少 AMR 基因释放到土壤-水环境中。
