摘要
      抗生素的广泛和不适当使用已被证明会增加抗生素和抗微生物耐药性基因（ARGs）在水生环境和生物体中的传播。用于治疗人类和动物疾病的抗生素在全球范围内不断增加。然而，合法的抗生素浓度对淡水环境中的海底消费者的影响仍不清楚。在本研究中，我们测试了绿脓杆菌在高浓度和低浓度沉积物有机物（碳[C]和氮[N]）下对氟苯尼考（FF）的生长反应84天。我们使用宏基因组测序和分析来表征FF和沉积物有机物对肠道细菌群落、ARGs和代谢途径的影响。沉积物中高浓度的有机物影响了铜绿假单胞菌的生长、肠道细菌群落、肠道ARGs和微生物组代谢途径。暴露于高有机物含量沉积物后，铜绿假单胞菌的生长显著增加。肠内富含门水平的变形杆菌和属水平的气单胞菌。特别是，在高有机物含量沉积物组的肠道中富集的四种机会性病原体的片段，即嗜水气单胞菌、豚鼠气单胞菌，veronii气单胞杆菌和salmonicida气单胞球菌，携带14个ARGs。铜绿假单胞菌肠道微生物组的代谢途径被激活，并与沉积物有机物浓度呈显著正相关。此外，联合暴露于沉积物C、N和FF可能会抑制遗传信息处理和代谢功能。本研究的结果表明，应进一步研究抗生素耐药性从底栖动物传播到淡水湖的高营养级。
Abstract
Widespread and inappropriate use of antibiotics has been shown to increase the spread of antibiotics and antimicrobial resistance genes (ARGs) in aquatic environments and organisms. Antibiotic use for the treatment of human and animal diseases is increasing continuously globally. However, the effects of legal antibiotic concentrations on benthic consumers in freshwater environments remain unclear. In the present study, we tested the growth response of Bellamya aeruginosa to florfenicol (FF) for 84 days under high and low concentrations of sediment organic matter (carbon [C] and nitrogen [N]). We characterized FF and sediment organic matter impact on the bacterial community, ARGs, and metabolic pathways in the intestine using metagenomic sequencing and analysis. The high concentrations of organic matter in the sediment impacted the growth, intestinal bacterial community, intestinal ARGs, and microbiome metabolic pathways of B. aeruginosa. B. aeruginosa growth increased significantly following exposure to high organic matter content sediment. Proteobacteria, at the phylum level, and Aeromonas at the genus level, were enriched in the intestines. In particular, fragments of four opportunistic pathogens enriched in the intestine of high organic matter content sediment groups, Aeromonas hydrophila, Aeromonas caviae, Aeromonas veronii, and Aeromonas salmonicida, carried 14 ARGs. The metabolic pathways of the B. aeruginosa intestine microbiome were activated and showed a significant positive correlation with sediment organic matter concentrations. In addition, genetic information processing and metabolic functions may be inhibited by the combined exposure to sediment C, N, and FF. The findings of the present study suggest that antibiotic resistance dissemination from benthic animals to the upper trophic levels in freshwater lakes should be studied further.

https://www.mdpi.com/2076-2607/11/3/765