Wang Lixiao, Chai Baofeng
Shanxi Key Laboratory of Ecological Restoration for Loess Plateau, Institute of Loess Plateau, Shanxi University, Taiyuan, China.
Front Microbiol. 2022 Mar 9;13:857046. doi: 10.3389/fmicb.2022.857046. eCollection 2022.
The use of antimicrobials in intensive poultry production is becoming increasingly common because of its high throughput of meat and egg products. However, the profile of antibiotic resistance genes (ARGs) and the underlying mechanisms in different breeding scale farms were not fully explored. The study examined the profiles of ARGs in layer manure from three free-range and 12 intensive layer farms with different scales (N500, N5000, N10000, and N20000). A quantitative PCR (qPCR) array was used to quantify ARGs, and microbial community structure was analyzed by 16S rRNA gene sequencing. A total of 48 ARGs, belonging to seven major types, were identified in the layer manure samples, with 2, M-01, and B being the predominant ones. The abundance, diversity, and mobility potential of ARGs in layer manure changed significantly with the increasing of the breeding scale. The abundances of total ARGs had significantly positive correlations with mobile genetic elements (MGEs), suggesting the mobility potential of ARGs in layer manure samples. Bacterial abundance did not show significant differences among the five group manure samples. However, bacterial diversity showed an increasing trend along the breeding scale. Pathogenic increased in the largest-scale layer manure samples and showed significant positive correlations with most ARGs. Network analysis revealed significant co-occurrence patterns between ARGs and microbial taxa, indicating ARGs had a wide range of bacterial hosts. Proteobacteria and Firmicutes were potential hosts for tetracycline and macrolide-lincosamide-streptogramin B (MLSB) resistant genes. Our results indicated that the expansion of the breeding scale of a farm promotes the abundance, diversity, and mobility potential of ARGs in layer manure.
由于集约化家禽生产中肉蛋产品产量高，抗菌药物的使用越来越普遍。然而，不同养殖规模养殖场中抗生素抗性基因（ARGs）的概况及其潜在机制尚未得到充分研究。本研究调查了来自3个放养式和12个不同规模（N500、N5000、N10000和N20000）集约化蛋鸡养殖场的蛋鸡粪便中ARGs的概况。使用定量PCR（qPCR）阵列对ARGs进行定量，并通过16S rRNA基因测序分析微生物群落结构。在蛋鸡粪便样本中总共鉴定出48种ARGs，分属7种主要类型，其中2、M-01和B型为优势类型。随着养殖规模的增加，蛋鸡粪便中ARGs的丰度、多样性和移动潜力发生了显著变化。总ARGs的丰度与移动遗传元件（MGEs）呈显著正相关，表明蛋鸡粪便样本中ARGs具有移动潜力。五组粪便样本中的细菌丰度没有显著差异。然而，细菌多样性随着养殖规模的增加呈上升趋势。最大规模蛋鸡粪便样本中的病原菌增加，且与大多数ARGs呈显著正相关。网络分析揭示了ARGs与微生物类群之间存在显著的共现模式，表明ARGs有广泛的细菌宿主。变形菌门和厚壁菌门是四环素和大环内酯-林可酰胺-链阳菌素B（MLSB）抗性基因的潜在宿主。我们的结果表明，养殖场养殖规模的扩大促进了蛋鸡粪便中ARGs的丰度、多样性和移动潜力。
