樱桃萝卜对抗生素的富集及其潜在风险

为探究土壤抗生素污染的潜在生态和健康风险,于2021年6～9月进行温室土培樱桃萝卜试验,每隔6d向土壤中施用土霉素(OTC)或链霉素(STR)污水,并对其中生长的樱桃萝卜的生物量、萝卜组织抗生素含量和菌群耐药性进行分析.同时,通过风险商法、摄入量计算和小鼠饲喂试验对萝卜植株残留的抗生素和抗性细菌的潜在人体健康风险进行评估.结果表明,与未施用抗生素对照组相比,OTC的连续施用在第74d显著促进了萝卜植株生长,使其总生物量提高了23.1%,而STR的连续施用对萝卜植株的生长并无显著影响;萝卜植株对土壤中施入的两种抗生素均有一定的富集能力,STR在组织中的残留量高于的OTC1～2个数量级,抗生素在植物生长初期主要富集在叶中,生长后期在肉质根根颈部中的富集量显著增加(P<0.05);抗生素的施用使萝卜植株组织中可培养OTC和STR抗性细菌占总可培养细菌的比率分别增加了2.48×10^-6%～5.05×10^-4%和0.19%～3.32%;食用经抗生素暴露后的萝卜肉质根根颈部可增加机体对抗生素和抗生素抗性细菌的摄入量,但其健康风险较低(评估的风险商指...

Enrichment of antibiotics in cherry radish and its potential risk

To explore the potential ecological and health risks of soil antibiotic pollution, a greenhouse pot experiment on cherry radishes was conducted from June to September 2021. Oxytetracycline (OTC) or streptomycin (STR) contaminated water was applied to soil every 6days, and the biomass, plant uptake of antibiotics, and the antibiotic resistance characteristics of the microbiome of cherry radish were analyzed. In addition, the potential human health risks of residual antibiotic and antibiotic-resistant bacteria (ARB) in radish plants were evaluated by risk quotient, calculation of intake index, and the mouse feeding tests. The results showed that continuous application of OTC significantly promoted the growth of radish plants and increased the total biomass of radish plants by 23.1% on 74 days compared with the non-antibiotic applied control group, while continuous application of STR had no significant effect on the growth of radish plants. Radish plants accumulated a certain amount of the applied two antibiotics, and the residual amount of STR in tissues was higher than OTC by 1~2 orders of magnitude. Antibiotics were mainly enriched in leaves at the early growth stage, and antibiotic residue in the neck of fleshy roots at the later growth stage was significantly increased (P < 0.05). The proportion of culturable OTC- and STR-resistant bacteria in total culturable bacteria increased by 2.48×10^-6%~5.05 ×10^-4% and 0.19%~3.32%, respectively. Consumption of the neck of fleshy roots exposed to antibiotics could increase the body's intake of antibiotics and ARB, but the associated health risk was relatively low, as the assessed risk index HQ was less than 0.1 and the antibiotic residue in feces of mice eating radish plants was below the detection limit.