Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; Department of Microbiology, Federal University of Technology, PMB 704 Akure, Nigeria.
Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China.
J Environ Sci (China). 2022 Mar;113:394-402. doi: 10.1016/j.jes.2021.06.024. Epub 2021 Jul 17.
The use of maggots derived from chicken faeces as fish diets might serve as a vehicle for the widespread of multiple antibiotic resistant bacteria (ARB) in the environment. Heavy water labeled single-cell Raman spectroscopy (DO-Raman) was applied to detect the metabolic responses of indigenous bacteria in chicken faeces and maggots to different concentrations of combined colistin, kanamycin, and vancomycin. By incubating the samples with DO and antibiotics, metabolically active bacterial cells to antibiotics were distinguished from those inactive by the exhibition of C-D Raman band. Using the C-D band as a universal metabolic biomarker, 96% and 100% of cells in chicken faeces and maggots were revealed to be metabolically active to 1 × minimum inhibition concentration (MIC) of the afore-mentioned antibiotics. A noticeable decrease in the percentage of active cells from 96% to 76% in faeces and 100% to 93% in maggots was observed at 5 × MIC of antibiotics. However, these ratios were still far above that obtained from the same faeces (1.84%) and maggots (0.51%) samples using a cultivation method, indicating the wide presence of nongrowing but metabolically active bacterial cells under antibiotic treatment. Conclusively, the culture-independent DO-Raman approach detected and quantified a large portion of metabolically active indigenous bacteria to multiple antibiotics in their native environments, illustrating the great potential risks of these active cells to spread antibiotic resistance via food chain.
使用源自鸡粪便的蛆作为鱼类饲料，可能成为环境中多重耐药细菌（ARB）广泛传播的媒介。重水标记单细胞拉曼光谱（DO-Raman）被应用于检测鸡粪便和蛆中土著细菌对不同浓度联合多粘菌素、卡那霉素和万古霉素的代谢反应。通过将样品与 DO 和抗生素孵育，表现出 C-D 拉曼带的代谢活跃的细菌细胞与对抗生素不活跃的细胞区分开来。使用 C-D 带作为通用代谢生物标志物，发现鸡粪便和蛆中 96%和 100%的细胞对上述抗生素的 1×最小抑制浓度（MIC）表现出代谢活性。在抗生素 5×MIC 时，粪便中活跃细胞的比例从 96%显著下降到 76%，而蛆中的比例从 100%下降到 93%。然而，这些比例仍然远高于使用培养方法从相同粪便（1.84%）和蛆（0.51%）样本中获得的比例，这表明在抗生素处理下，存在大量非生长但代谢活跃的细菌细胞。总之，这种无需培养的 DO-Raman 方法在其天然环境中检测和定量了大量对多种抗生素代谢活跃的土著细菌，说明了这些活跃细胞通过食物链传播抗生素耐药性的巨大潜在风险。
