Accumulation of antibiotics and heavy metals in meat duck deep litter and their role in persistence of antibiotic-resistant Escherichia coli in different flocks on one duck farm
Accumulation of antibiotics and heavy metals in meat duck deep litter and their role in persistence of antibiotic-resistant Escherichia coli in different flocks on one duck farm
复制标题
肉鸭垫料中抗生素和重金属的积累及其对同一鸭场不同鸡群中耐药大肠杆菌持续存在的作用
DOI：
10.3382/ps/pew368
复制
发表时间：
2017-04-01
期刊：
影响因子：
4.4
通讯作者：
Yao, W.
中科院分区：
文献类型：
--
作者：
Lin, Y.;Zhao, W.;Yao, W.
如果管理不善，肉鸭深窝被认为是细菌抗生素耐药性进化的理想环境。本研究的目的是表征抗生素和重金属在深层凋落物中的积累及其在大肠杆菌抗生素耐药性持续性中的作用，并评估深层凋落物的使用寿命。从3个畜舍（0、4和8轮肉鸭育肥，d 34）和9个鸡群的初始、中间和最后阶段的深窝中收集样品，在对照试验中已知抗生素的消耗量。测定了饲料和窝仔中抗生素和重金属的消耗水平。E.分离大肠杆菌（n = 147），采用Eric-PCR和系统发育分组技术进行分型，同时测定抗生素和重金属的最低抑菌浓度。本研究证实了强力霉素和多种重金属在深层凋落物中的持续积累。在使用过的深窝中（第4轮和第8轮），某些细菌对强力霉素（16 mg/L、100 mg/L）或氧氟沙星（8 g/mL、50 g/mL）的耐药性有所增加。E. 3个采样阶段分离的大肠埃希菌对氨苄青霉素、四环素、氟苯尼考和强力霉素均高度耐药。在来自深窝最后阶段的分离株中观察到对头孢噻呋、恩诺沙星、氧氟沙星和庆大霉素的耐药性增加。此外，在利用的深层凋落物中，耐锌、铜、镉菌株的比例和B2群菌株的数量均有所增加，且各阶段的菌株均以耐锌、铜、镉菌株为主。从第4轮到第8轮，Eric-PCR带型相同的菌株耐药性有所提高，同一轮不同畜舍的Eric-PCR带型相同的菌株耐药性仍存在差异。本研究表明，在长期使用抗生素和重金属的情况下，深层凋落物可能适合细菌耐药性的进化。
Meat duck deep litter is considered to be an ideal environment for the evolution of bacterial antibiotic resistance if it is under poor management. The aim of this study was to characterize the accumulation of antibiotics and heavy metals in the deep litter and their role in the persistence of antibiotic resistance of Escherichia coli, and evaluate the service life of the deep litter. Samples were collected from initial, middle, and final stages of deep litter within 3 barns (zero, 4, and 8 rounds of meat duck fattening, d 34) and 9 flocks, with known consumption of antibiotics in the controlled trail. The feed and litter levels of consumed antibiotics and heavy metals were measured. E. coli (n = 147) was isolated and typed by Eric-PCR and the phylogenetic grouping technique, while minimal inhibitory concentrations of antibiotics and heavy metals were measured. This study confirmed the continuous accumulation of doxycycline and many heavy metals in the deep litter. The population of resistant certain bacteria to doxycycline (16 mg/L, 100 mg/L) or ofloxacin (8 g/mL, 50 g/mL) increased in the used deep litter (rounds 4 and 8). E. coli isolated from the 3 stages of sampling were highly resistant to ampicillin, tetracycline, florfenicol, and doxycycline. Increased resistance to ceftiofur, enrofloxacin, ofloxacin, and gentamicin were seen in the isolates from the final stage of deep litter. In addition, the percentage of isolates tolerant to zinc, copper, and cadmium and the numbers of Group-B2 isolates all increased in the used deep litter, and the isolates of each stage belonged predominantly to commensal groups. The antibiotic resistance of isolates with identical Eric-PCR patterns had improved from round 4 to 8, and differences still existed in the resistance profiles of isolates with identical Eric-PCR patterns from different barns of the same round. This study concluded that deep litter could be suitable for the evolution of bacterial antibiotic-resistance under conditions of continuous usage or accumulation of antibiotics and heavy metals without proper management.