摘要

四环素类是用于家禽养殖的重要抗微生物药物，通过粪便和尿液积极排泄。粪便是肉鸡寝具的主要成分之一，通常用作有机肥料。因此，床上用品成为抗菌残留物进入环境的非预期载体，可能对公众健康构成极大的威胁。对于该耗尽研究，在治疗条件下用20％金霉素（CTC）处理60只肉鸡。然后在它们的粪便中测定CTC和4-epi-CTC的浓度。此外，这项工作还旨在检测这些粪便的抗菌活性和大肠杆菌分离株中四环素的表型易感性，以及tet（A），tet（B）和tet（G）抗性基因的存在。发现的CTC和4-epi-CTC浓度范围为179.5至665.8μg/ kg。基于这些数据，计算鸡粪的耗尽时间并设定为69天。所有样品均呈现抗微生物活性，并且在从这些样品中分离的细菌菌株中发现对四环素的抗性。在这些样品中也发现了抗性基因tet（A）和tet（B）。

Tetracyclines are important antimicrobial drugs for poultry farming that are actively excreted via feces and urine. Droppings are one of the main components in broiler bedding, which is commonly used as an organic fertilizer. Therefore, bedding becomes an unintended carrier of antimicrobial residues into the environment and may pose a highly significant threat to public health. For this depletion study, 60 broiler chickens were treated with 20% chlortetracycline (CTC) under therapeutic conditions. Concentrations of CTC and 4-epi-CTC were then determined in their droppings. Additionally, this work also aimed to detect the antimicrobial activity of these droppings and the phenotypic susceptibility to tetracycline in E. coli isolates, as well as the presence of tet(A), tet(B), and tet(G) resistance genes. CTC and 4-epi-CTC concentrations that were found ranged from 179.5 to 665.8 µg/kg. Based on these data, the depletion time for chicken droppings was calculated and set at 69 days. All samples presented antimicrobial activity, and a resistance to tetracyclines was found in bacterial strains that were isolated from these samples. Resistance genes tet(A) and tet(B) were also found in these samples. 

http://www.mdpi.com/1420-3049/23/6/1264