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.
Solís, Yendry; Chavarría, Guadalupe; García, Fernando; and Rodríguez, César
"EXPOSURE OF A TROPICAL SOIL TO MG/KG OF OXYTETRACYCLINE ELICITS HORMETIC RESPONSES IN THE CATABOLIC ACTIVITIES OF ITS MICROBIAL COMMUNITY,"
Dose-Response: An International Journal:
3, Article 13.
Available at: http://scholarworks.umass.edu/dose_response/vol9/iss3/13