Facultad de Microbiología, Universidad de Costa Rica.
Dose Response. 2011;9(3):434-41. doi: 10.2203/dose-response.10-045.Rodriguez. Epub 2011 Apr 30.
Many farmers in developing countries protect their crops with oxytetracycline and fertilize their farmlands with manure from animals that received this drug as growth promoter. In this study, a tropical soil was exposed to 0.1 mg kg(-1), 1 mg kg(-1), and 10 mg kg(-1) of oxytetracycline for 22 days to evaluate whether this antibiotic alters the capacity of a soil microbial community to metabolize 31 carbon sources. The communities exposed to 1 and 10 mg kg(-1) of oxytetracycline exhibited reduced catabolic activities for 3 and 6 substrates, respectively. In contrast, the communities exposed to 0.1 mg kg(-1) of oxytetracycline showed higher catabolic activities than the controls and the other two treatments for 19 substrates. These data reveal a hormetic response at the community level not previously described for soil bacteria and oxytetracycline.
许多发展中国家的农民使用土霉素来保护作物，并使用接受土霉素作为生长促进剂的动物粪便来给农田施肥。在这项研究中，将 0.1、1 和 10 mg/kg 的土霉素暴露在热带土壤中 22 天，以评估这种抗生素是否会改变土壤微生物群落代谢 31 种碳源的能力。暴露于 1 和 10 mg/kg 土霉素的群落对 3 和 6 种基质的代谢活性分别降低。相比之下，暴露于 0.1 mg/kg 土霉素的群落对 19 种基质的代谢活性高于对照组和其他两种处理组。这些数据显示，在社区层面上出现了一种以前未被描述的、对土壤细菌和土霉素的激素反应。
