Tetracycline In Manure Research Articles

Abiotic transformation products of tetracycline and chlortetracycline in salt solutions and manure

Tetracyclines belong to the group of the most applied antibiotics in veterinary medicine worldwide. Due to their incomplete absorption and/or metabolism in the animal gut, tetracyclines are frequently detected in manure samples. Within the matrix, an elimination of these compounds has been reported in several studies. However, only little information about potential transformation products of tetracyclines in manure and the environment is available. Therefore, the fate of tetracycline (TC) and chlortetracycline (CTC) was investigated in aqueous solutions and manure. Abiotic incubation of TC in phosphate buffer led to a remarkable red-brown coloring of the solution. Subsequent compound isolation and structure elucidation by MS/MS and NMR techniques revealed the formation of seco-cycline A, a compound formerly described as a fungal biotransformation product of TC. For CTC, two comparable products were identified which were derived from its isomeric form isoCTC. All transformation products showed no antimicrobial activity for concentrations up to 500 mg L−1. When TC and CTC were incubated in cow manure for 7 d, the above mentioned three transformation products were also formed in this complex matrix (up to 5.1 mg kg−1). Manure, soil and leachate samples from Lower Saxony revealed the presence of seco-cycline A in manure and soil, but not in water. To obtain a better insight in the fate of tetracyclines in environmental matrices, future analytical and ecotoxicological studies dealing with this subject should include the analysis especially of seco-cycline A.

Immobilization of tetracyclines in manure and manure-amended soils using aluminum-based drinking water treatment residuals.

Veterinary antibiotics (VAs) are emerging contaminants of concern in the environment, mainly due to the potential for development of antibiotic-resistant bacteria and effect on microbiota that could interfere with crucial ecosystem functions such as nutrient cycling and decomposition. High levels of VAs such as tetracyclines (TCs) have been reported in agricultural soils amended with manure, which also has the potential to cause surface and groundwater contamination. Several recent studies have focused on developing methods to immobilize VAs such as composting with straw, hardwood chips, commercial biochar, aeration, mixing, heat treatment, etc. The major shortcomings of these methods include high cost and limited effectiveness. In the current study, we assessed the effectiveness of aluminum-based drinking water treatment residuals (Al-WTR) as a "green" sorbent to immobilize TCs in manure and manure-applied soils with varying physicochemical properties by laboratory incubation study. Results show that Al-WTR is very effective in immobilizing tetracycline (TTC) and oxytetracycline (OTC). The presence of phosphate resulted in significant (p < 0.01) decrease in TTC/OTC sorption by Al-WTR, but the presence of sulfate did not. attenuated total reflection (ATR)-FTIR spectroscopy indicate that TTC and OTC likely forming surface complexes via inner-sphere-type bonds in soils, manure, and manure-applied soils amended with Al-WTR.

Estrone and 17β-estradiol mineralization in liquid swine manure and soil in the presence and absence of penicillin or tetracycline

Natural steroid estrogens (e.g., 17 β-estradiol) and antibiotics (e.g., penicillin) are chemicals detected in livestock manure storage facilities and in manure-amended agricultural soils. The fate of natural steroid estrogens in these media has been studied for the past two decades but seldom in association with antibiotics. This factorial experiment examined estrone (E1) and 17 β-estradiol (E2) mineralization in liquid swine manure, soil and manure-amended soil containing 0, 40 and 200 mg kg−1 penicillin or tetracycline. Maximum mineralization (MAX) across treatments ranged from 13.5% to 49.9% for E1 and from 15.4% to 51.2% for E2. Estrogen mineralization almost always significantly decreased in the order of: manure > soil amended with a low rate of manure = soil > soil amended with a high rate of manure, suggesting that periodically agitated manure was a more favorable medium for biotic removal of estrogens than soil. Both rates of tetracycline in manure induces a lag phase of 40 to 50 days prior to the onset of a log phase of mineralization, and tetracycline at 200 mg kg−1 significantly decreased E1 and E2 MAX in manure. For soils amended with a high rate of manure, penicillin at 200 mg kg−1 significantly decreased E1 and E2 MAX and also the other antibiotic additions resulted in numerically lesser E1 and E2 MAX values, relative to soils free of antibiotics. We conclude that storage of liquid swine manure for 3 to 4 months with periodic agitation prior to application to agricultural land may reduce the potential for estrogens to become environmental contaminants, but that the persistence of estrogens in manure storage lagoons is also influenced by farm management practices such as the types and rates of antibiotics administered to livestock. When both estrogens and antibiotics are present in manure applied to soils, estrogens may have slower dissipation rates in soil particularly when manure is applied at high rates or not mechanically incorporated in the surface horizon.

Fate of tetracyclines in swine manure of three selected swine farms in China

Veterinary antibiotics can enter the environment due to the common practice of land application of manure from treated animals. The environmental fate of tetracyclines in swine manure after composting and field application remains largely unknown. This study analyzed the concentrations of tetracyclines in manure, manure-based compost and compost amended soil in selected swine farms from Beijing, Jiaxing and Putian, China to determine the dilution effects of antibiotics when released into the soil environment. The results demonstrate that residues of antibiotics were detected in all samples and chlortetracycline as well as its degradation products should be regarded critically concerning their potential ecotoxicity. Application of manure-based compost to soil could reduce the possible risk posed by antibiotic contamination, but the trigger value of 100 μg/kg was still exceeded in soil samples (776.1 μg/kg dw) from Putian City after application of compost. Field studies such as the present one can help to improve the routine administration of antibiotic-containing composted manure.

Analysis of tetracycline antibiotics in soil: Advances in extraction, clean-up, and quantification

Residues of tetracyclines end up in the environment due to the common practice of land application of manure from treated animals. The environmental behavior and the fate of tetracyclines in manure and soil after cropland application remain largely unknown. The lack of information on the nature of the biodegradation products of tetracyclines formed at environmentally-relevant concentrations is mostly due to analytical difficulties encountered when trying to analyze trace levels of these compounds in the presence of complex matrices. Liquid chromatography coupled to mass spectrometry (LC-MS) has become widely used in detecting polar pollutants such as antibiotics. In applying LC-MS for environmental investigations, the analyst is faced with two major challenges: poor detectability of analytes; and, highly variable matrix interferences that compromise quantification. To improve our understanding of the fate and effects of tetracycline antibiotics in the environment, improved methods for detection, quantification, and unknown identification are needed. In this review, we discuss strategies for sample preparation, extraction, clean-up using solid-phase extraction (SPE) and molecularly-imprinted polymers (MIPs), and analysis of tetracyclines and their transformation products in soil, in order to facilitate future environmental fate studies, and to challenge analytical chemists to develop the necessary tools to allow a complete risk assessment of other pharmaceutical contaminants in the environment.