Illinois Sustainable Technology Center, Prairie Research Institute, Department of Animal Sciences, University of Illinois at Urbana-Champaign, 1 Hazelwood Drive, Champaign, Illinois 61820, United States.
J Agric Food Chem. 2011 Sep 28;59(18):10176-81. doi: 10.1021/jf202325c. Epub 2011 Sep 6.
Ceftiofur is a third-generation cephalosporin antibiotic that has been widely used to treat bacterial infections in concentrated animal feeding operations (CAFOs). Land application of CAFO waste may lead to the loading of ceftiofur residues and its metabolites to the environment. To understand the potential contamination of the antibiotic in the environment, the degradation kinetics and mechanisms of ceftiofur in solutions blended with and without the recycled water derived from a beef farm were investigated. The transformation of ceftiofur in aqueous solutions in the presence of the CAFO recycled water was the combined process of hydrolysis and biodegradation. The total degradation rates of ceftiofur at 15 °C, 25 °C, 35 °C, and 45 °C varied from 0.4-2.8×10(-3), 1.4-4.4×10(-3), 6.3-11×10(-3), and 11-17×10(-3) h(-1), respectively, in aqueous solutions blended with 1 to 5% CAFO recycled water. Hydrolysis of ceftiofur increased with incubation temperature from 15 to 45 °C. The biodegradation rates of ceftiofur were also temperature-dependent and increased with the application amounts of the recycled CAFO water. Cef-aldehyde and desfuroylceftiofur (DFC) were identified as the main biodegradation and hydrolysis products, respectively. This result suggests that the primary biodegradation mechanism of ceftiofur was the cleavage of the β-lactam ring, while hydrolytic cleavage occurred at the thioester bond. Unlike DFC and ceftiofur, cef-aldehyde does not contain a β-lactam ring and has less antimicrobial activity, indicating that the biodegradation of ceftiofur in animal wastewater may mitigate the potentially adverse impact of the antibiotic to the environment.
头孢噻呋是一种第三代头孢菌素抗生素，已广泛用于治疗集中式动物饲养场（CAFO）中的细菌感染。CAFO 废物的土地应用可能导致头孢噻呋残留及其代谢物加载到环境中。为了了解抗生素在环境中的潜在污染，研究了头孢噻呋在与来自牛肉养殖场的再生水混合和不混合的溶液中的降解动力学和机制。在 CAFO 再生水存在的情况下，水溶液中头孢噻呋的转化是水解和生物降解的联合过程。在含有 1%至 5%CAFO 再生水的水溶液中，头孢噻呋在 15°C、25°C、35°C 和 45°C 下的总降解速率分别为 0.4-2.8×10(-3)、1.4-4.4×10(-3)、6.3-11×10(-3)和 11-17×10(-3) h(-1)。随着孵化温度从 15°C 升高到 45°C，头孢噻呋的水解增加。头孢噻呋的生物降解速率也与温度有关，并随再生 CAFO 水的应用量增加而增加。头孢醛和去呋喃头孢噻呋（DFC）分别被鉴定为主要的生物降解和水解产物。这一结果表明，头孢噻呋的主要生物降解机制是β-内酰胺环的裂解，而硫酯键发生水解裂解。与 DFC 和头孢噻呋不同，头孢醛不含β-内酰胺环，抗菌活性较低，这表明动物废水中头孢噻呋的生物降解可能减轻了抗生素对环境的潜在不利影响。
