发布者：抗性基因网 时间：2020-03-24 浏览量：936
摘要
背景：抗菌药物已广泛应用于动物养殖场，以预防和治疗动物疾病和促进生长。抗菌药物可以改变动物粪便中的细菌群落，增强其抵抗力。我们采用全基因组分析方法，在低剂量和治疗剂量水平下，研究了金霉素整个治疗过程中肉鸡粪便中细菌群落的变化、抗生素抗性基因（ARGs）的变化及其寄主。
结果：金霉素对抗性的影响依赖于特定的ARG亚型，而不仅仅是整个群落水平的ARG。金霉素治疗剂量促进四环素耐药基因（tetA和tetW）的丰度，抑制多药耐药基因（mdtA、mdtC、mdtK、ompR和TolC）。金霉素的治疗剂量主要是由于大肠杆菌/志贺氏菌的减少（从72%下降到58%）导致蛋白菌的丢失。金霉素对大肠杆菌的抑制作用是治疗剂量组多药耐药基因减少的主要原因。在金霉素处理下，双歧杆菌携带tetW富集了ARG宿主双歧杆菌。大肠埃希菌一直是多药耐药基因的主要宿主，而在金霉素治疗剂量下，由大肠埃希菌转变为氨基糖苷类耐药基因的克雷伯菌。
结论：我们首次从亚基因组的角度研究了抗生素介导的鸡粪便中含有细菌宿主的精氨酸的变化。这些结果表明，抗生素诱导的粪便微生物群落结构的变化伴随着粪便微生物群落中携带特定arg的细菌宿主数量的变化。这些发现将有助于优化治疗方案，有效地治疗家禽养殖场的抗药性病原体。接触金霉素的鸡粪便微生物群的抗性变化。
Antimicrobial agents have been widely used in animal farms to prevent and treat animal diseases and to promote growth. Antimicrobial agents may change the bacterial community and enhance the resistome in animal feces. We used metagenome-wide analysis to investigate the changes in bacterial community, variations in antibiotic resistance genes (ARGs), and their bacterial hosts in the feces of broiler chickens over a full-treatment course of chlortetracycline at low and therapeutic dose levels.
The effects of chlortetracycline on resistome were dependent on the specific ARG subtypes and not simply the overall community-level ARGs. Therapeutic dose of chlortetracycline promoted the abundance of tetracycline resistance genes (tetA and tetW) and inhibited multidrug resistance genes (mdtA, mdtC, mdtK, ompR, and TolC). The therapeutic dose of chlortetracycline led to loss of Proteobacteria mainly due to the decrease of Escherichia/Shigella (from 72 to 58%). Inhibition of Escherichia by chlortetracycline was the primary reason for the decrease of genes resistant to multiple drugs in the therapeutic dose group. The ARG host Bifidobacterium were enriched due to tetW harbored by Bifidobacterium under chlortetracycline treatment. Escherichia was always the major host for multidrug resistance genes, whereas the primary host was changed from Escherichia to Klebsiella for aminoglycoside resistance genes with the treatment of therapeutic dose of chlortetracycline.
We provided the first metagenomic insights into antibiotic-mediated alteration of ARG-harboring bacterial hosts at community-wide level in chicken feces. These results indicated that the changes in the structure of antibiotic-induced feces microbial communities accompany changes in the abundance of bacterial hosts carrying specific ARGs in the feces microbiota. These findings will help to optimize therapeutic schemes for the effective treatment of antibiotic resistant pathogens in poultry farms. Resistome variations in faecal microbiome of chickens exposed to chlortetracycline.