Occurrence of Chloramphenicol in Crops through Natural Production by Bacteria in Soil

Abstract

Due to the unexpected findings of the banned antibiotic chloramphenicol in products of animal origin, feed, and straw, the hypothesis was studied that the drug is naturally present in soil, through production by soil bacteria, and subsequently can be transferred to crops. First, the stability of chloramphenicol in soil was studied. The fate of chloramphenicol highly depends on soil type and showed a half-life of approximately one day in nonsterile topsoil. It was found to be more stable in subsoil and sterile soils. Second, the production of chloramphenicol in soil was studied, and it was confirmed that Streptomyces venezuelae can produce chloramphenicol at appreciable amounts in nonsterile soil. Third, a transfer study was carried out using wheat and maize grown on three different soils that were weekly exposed to aqueous chloramphenicol solutions at different levels. Chloramphenicol was taken up by crops as determined by chiral liquid chromatography coupled to tandem mass spectrometric analysis, and the levels in crops were found to be bioavailability related. It was concluded that chloramphenicol residues can occur naturally in crops as a result of the production of chloramphenicol by soil bacteria in their natural environment and subsequent uptake by crops.

Novel pitaya-inspired well-defined core–shell nanospheres with ultrathin surface imprinted nanofilm from magnetic mesoporous nanosilica for highly efficient chloramphenicol removal

“…Nevertheless, illegal usage of CAP drug still continues in the lowincome areas, owing to its low cost and easy availability. Many previous reports showed that the ingested CAP could not be completely metabolized, and a relatively high proportion of parent drug were discharged into aquatic environment through the excrement [4,5]. As a result, CAP has been frequently determined in many waters [6][7][8].…”

Predation and selection for antibiotic resistance in natural environments

“…Contrasting these observations on the occurrence of antibiotics in natural environments, Berendsen et al. () recently observed a high production of the antibiotic compound chloramphenicol by a population of added soil bacteria.…”

Antibiotic residues and resistance in the environment

“…In many studies on antibiotic degradation in the environment, it was impossible to distinguish between the rate of biotic and abiotic degradation. However, an experiment comparing degradation of chloramphenicol in sterilized vs unsterilized soil convincingly showed the major role of the native microbial population in the degradation of this antibiotic residue (Berendsen, 2013). The extent, kinetics and process of degradation are mainly influenced by physicochemical properties of antibiotics such as structure, concentration, solubility, adsorption ability to soil, fixation ability to pores of soil matrix, and by environmental conditions, such as temperature, rainfall, and humidity (Tolls, 2001;Halling-Sørensen, 2002;Sarmah, 2006).…”

“…Apart from their effects on soil microbial communities, the presence of antibiotic residues in the environment has also repeatedly been show to result in residues in crops (Kumar, 2005b;Dolliver, 2008;Bassil, 2013;Chitescu, 2013;Berendsen, 2013).…”