Selection for antibiotic resistance in complex microbial communities

越来越清楚的是，自然环境在抗生素耐药性的进化和传播中起着重要作用。该研究将确定基因流的机制基础和意义，该基因流是居住在污染的自然环境（如废水处理厂（WWTPs）下游）的细菌中抗菌素耐药基因丰度的基础。目前尚不清楚与污水处理厂相关的抗生素耐药微生物的流行率增加是否是由于耐药微生物的持续排放，或者细菌（如多重耐药大肠杆菌）是否是由于耐药微生物的持续排放。大肠杆菌在环境污染物（包括抗生素残留）的选择下，通过水平基因转移（HGT）在水体沉积物中存活和/或获得抗性基因。该项目将研究复杂群落中的抗性选择，利用围隔生态系统研究，使用文化和文化独立的方法进行调查。后者将包括实时聚合酶链反应，用于关键标记基因的计数和下一代测序，以确定单一抗生素、不同类别抗生素的混合物和污染废水的实地样本对所有已知耐药基因相对丰度的影响。这些知识将用于支持环境政策制定和环境风险管理。

It is becoming increasingly clear that the natural environment plays an important role in the evolution and dissemination of antibiotic resistance. This studentship will determine the mechanistic basis and significance of gene flow that underlies the abundance of antimicrobial resistance genes in bacteria inhabiting polluted natural environments such as downstream of waste water treatment plants (WWTPs). It is unclear whether increased prevalence of antibiotic resistant organisms associated with WWTPs is due to constant emissions of resistant organisms or whether bacteria such as multi-drug resistant E. coli persist and/or acquire resistance genes by horizontal gene transfer (HGT) in aquatic sediments under selection by environmental pollutants including antibiotic residues. This project will study selection for resistance in complex communities utilising mesocosm studies interrogated using culture and culture independent methods. The latter will include real-time PCR for enumeration of key marker genes and next generation sequencing (NGS) to determine the effects of single antibiotics, mixtures of different classes of antibiotic and field samples of polluted effluents on relative abundance of all known resistance genes. This knowledge will be used to support environmental policy development and environmental risk management.