Gao Lili, Hu Jiaqing, Zhang Xiaodan, Wei Liangmeng, Li Song, Miao Zengmin, Chai Tongjie
College of Veterinary Medicine, Shandong Agricultural University Tai'an, China ; Sino-German Cooperative Research Centre for Zoonosis of Animal Origin Shandong Province Tai'an, China ; Key Laboratory of Animal Biotechnology and Disease Control and Prevention of Shandong Province Tai'an, China.
College of Life Sciences, Taishan Medical University Tai'an, China.
Front Microbiol. 2015 Apr 14;6:313. doi: 10.3389/fmicb.2015.00313. eCollection 2015.
The prevalence of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (E. coli) is increasing rapidly in both hospital environments and animal farms. A lot of animal manure has been directly applied into arable fields in developing countries. But the impact of ESBL-positive bacteria from animal manure on the agricultural fields is sparse, especially in the rural regions of Tai'an, China. Here, we collected 29, 3, and 10 ESBL-producing E. coli from pig manure, compost, and soil samples, respectively. To track ESBL-harboring E. coli from agricultural soil, these isolates of different sources were analyzed with regard to antibiotic resistance profiles, ESBL genes, plasmid replicons, and enterobacterial repetitive intergenic consensus (ERIC)-polymerase chain reaction (PCR) typing. The results showed that all the isolates exhibited multi-drug resistant (MDR). CTX-M gene was the predominant ESBL gene in the isolates from pig farm samples (30/32, 93.8%) and soil samples (7/10, 70.0%), but no SHV gene was detected. Twenty-five isolates contained the IncF-type replicon of plasmid, including 18 strains (18/32, 56.3%) from the pig farm and 7 (7/10, 70.0%) from the soil samples. ERIC-PCR demonstrated that 3 isolates from soil had above 90% genetic similarity with strains from pig farm samples. In conclusion, application of animal manure carrying drug-resistant bacteria on agricultural fields is a likely contributor to antibiotic resistance gene spread.
在医院环境和养殖场中，产超广谱β-内酰胺酶（ESBL）的大肠杆菌（E. coli）的流行率正在迅速上升。在发展中国家，大量动物粪便被直接施用于耕地。但是，来自动物粪便的ESBL阳性细菌对农田的影响却很少被研究，尤其是在中国泰安的农村地区。在这里，我们分别从猪粪、堆肥和土壤样本中收集了29株、3株和10株产ESBL的大肠杆菌。为了追踪农田土壤中产ESBL的大肠杆菌，我们对这些不同来源的分离株进行了抗生素耐药谱、ESBL基因、质粒复制子和肠杆菌重复基因间共识（ERIC）-聚合酶链反应（PCR）分型分析。结果表明，所有分离株均表现出多重耐药（MDR）。CTX-M基因是猪场样本（30/32，93.8%）和土壤样本（7/10，70.0%）中分离株的主要ESBL基因，但未检测到SHV基因。25株分离株含有IncF型质粒复制子，其中包括来自猪场的18株（18/32，56.3%）和来自土壤样本的7株（7/10，70.0%）。ERIC-PCR结果显示，3株来自土壤的分离株与猪场样本中的菌株具有90%以上的遗传相似性。总之，在农田中施用携带耐药菌的动物粪便可能是抗生素耐药基因传播的一个原因。
