Kirchner Miranda, Mafura Muriel, Hunt Theresa, Abu-Oun Manal, Nunez-Garcia Javier, Hu Yanmin, Weile Jan, Coates Anthony, Card Roderick, Anjum Muna F
Department of Bacteriology, Animal and Plant Health Agency Addlestone, UK.
Specialist Scientific Services Department, Animal and Plant Health Agency Addlestone, UK.
Front Microbiol. 2014 Dec 17;5:722. doi: 10.3389/fmicb.2014.00722. eCollection 2014.
A yearlong study was performed to examine the effect of antibiotic administration on the bacterial gut flora. Gram-negative facultative anaerobic bacteria were recovered from the feces of healthy adult volunteers administered amoxicillin, minocycline or placebo, and changes determined in antimicrobial resistance (AMR) gene carriage. Seventy percent of the 1039 facultative anaerobic isolates recovered were identified by MALDI-TOF as Escherichia coli. A microarray used to determine virulence and resistance gene carriage demonstrated that AMR genes were widespread in all administration groups, with the most common resistance genes being bla TEM, dfr, strB, tet(A), and tet(B). Following amoxicillin administration, an increase in the proportion of amoxicillin resistant E. coli and a three-fold increase in the levels of bla TEM gene carriage was observed, an effect not observed in the other two treatment groups. Detection of virulence genes, including stx1A, indicated not all E. coli were innocuous commensals. Approximately 150 E. coli collected from 6 participants were selected for pulse field gel electrophoresis (PFGE), and a subset used for characterisation of plasmids and Phenotypic Microarrays (PM). PFGE indicated some E. coli clones had persisted in volunteers for up to 1 year, while others were transient. Although there were no unique characteristics associated with plasmids from persistent or transient isolates, PM assays showed transient isolates had greater adaptability to a range of antiseptic biocides and tetracycline; characteristics which were lost in some, but not all persistent isolates. This study indicates healthy individuals carry bacteria harboring resistance to a variety of antibiotics and biocides in their intestinal tract. Antibiotic administration can have a temporary effect of selecting bacteria, showing co-resistance to multiple antibiotics, some of which can persist within the gut for up to 1 year.
开展了一项为期一年的研究，以检验抗生素给药对肠道细菌菌群的影响。从服用阿莫西林、米诺环素或安慰剂的健康成年志愿者粪便中分离出革兰氏阴性兼性厌氧菌，并确定抗菌药物耐药性（AMR）基因携带情况的变化。在回收的1039株兼性厌氧菌分离株中，70%经基质辅助激光解吸电离飞行时间质谱（MALDI-TOF）鉴定为大肠杆菌。用于确定毒力和耐药基因携带情况的微阵列显示，AMR基因在所有给药组中广泛存在，最常见的耐药基因是bla TEM、dfr、strB、tet(A)和tet(B)。服用阿莫西林后，观察到耐阿莫西林大肠杆菌的比例增加，bla TEM基因携带水平增加了三倍，其他两个治疗组未观察到这种效果。对包括stx1A在内的毒力基因的检测表明，并非所有大肠杆菌都是无害的共生菌。从6名参与者中收集了约150株大肠杆菌用于脉冲场凝胶电泳（PFGE），并选择其中一部分用于质粒和表型微阵列（PM）的特征分析。PFGE表明，一些大肠杆菌克隆在志愿者体内持续存在长达1年，而其他克隆则是短暂存在。尽管持续性或短暂性分离株的质粒没有独特特征，但PM分析显示，短暂性分离株对一系列防腐剂和四环素具有更大的适应性；一些但并非所有持续性分离株都失去了这些特征。这项研究表明，健康个体的肠道中携带对多种抗生素和杀菌剂具有耐药性的细菌。抗生素给药可产生选择细菌的暂时效应，这些细菌表现出对多种抗生素的共同耐药性，其中一些可在肠道内持续存在长达1年。
