Development of a 3-step sequential extraction method to investigate the fraction and affecting factors of 21 antibiotics in soils.

Antibiotic exist in various states after entering agricultural soil through the application of manure, including the aqueous state (I), which can be directly absorbed by plants, and the auxiliary organic extraction state (III), which is closely associated with the pseudo-permanence of antibiotics. However, effective analytical methods for extracting and affecting factors on fractions of different antibiotic states remain unclear. In this study, KCl, acetonitrile/NaEDTA-McIlvaine buffer, and acetonitrile/water were successively used to extract states I, II, and III of 21 antibiotics in soil, and the recovery efficiency met the quantitative requirements.

Fluorescent tag reveals the potential mechanism of how indigenous soil bacteria affect the transfer of the wild fecal antibiotic resistance plasmid pKANJ7 in different habitat soils.

Plasmids have increasingly become a point of concern since they act as a vital medium for the dissemination of antibiotic resistance genes (ARGs). Although indigenous soil bacteria are critical hosts for these plasmids, the mechanisms driving the transfer of antibiotic resistance plasmids (ARPs) have not been well researched. In this study, we tracked and visualized the colonization of the wild fecal antibiotic resistance plasmid pKANJ7 in indigenous bacteria of different habitat soils (unfertilized soil (UFS), chemical fertilized soil (CFS), and manure fertilized soil (MFS)).