A longitudinal study to assess the persistence of vancomycin-resistant Enterococcus faecium (VREF) on an intensive broiler farm in the United Kingdom
A longitudinal study to assess the persistence of vancomycin-resistant Enterococcus faecium (VREF) on an intensive broiler farm in the United Kingdom
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DOI：
10.1111/j.1574-6968.2007.00911.x
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发表时间：
2007-10-01
影响因子：
2.1
通讯作者：
Pleydell, Eve
中科院分区：
文献类型：
--
作者：
Garcia-Migura, Lourdes;Liebana, Ernesto;Pleydell, Eve
在Avoparcin被禁止7年后，Vref仍可能被隔离在英国肉鸡行业的各个行业内。本研究的目的是评估在连续的禽群之间是否存在Vref的携带，对Vref进入肉鸡舍的可能途径进行初步调查，并跟踪生长鸟类Vref的动态。对传统肉鸡养殖场六座房屋中的两座进行了为期九次的走访。共从环境样本(95/843)和粪便样本(248/416)中回收了343个Vana Vref。队列清洁消毒前后VREF携带率差异有统计学意义(RR0.57，P=0.006)。99%的VREF菌株对5种以上抗生素耐药，其中42株(B)和32株(E)对ERM(B)和VAT(E)呈阳性反应。脉冲场凝胶电泳(PFGE)分型在15个不同的PFGE聚类群中鉴定出50种PFGE类型，相似性为90%，表明来自流行病学相关的肉鸡群和肉鸡舍的Vref群体中存在高度的遗传多样性。来自不同无性系的Tn1546的进一步鉴定表明，Tn类型的多样性较低，这表明抗性决定因素在不同遗传无性系之间的水平转移。因此，本研究不仅显示了VREF的持久性，而且显示了VREF的多药耐药谱系。
Seven years after the ban of avoparcin, VREF could still be isolated within sectors of the UK broiler industry. The aim of this study was to assess whether there is a carryover of VREF between consecutive flocks of birds, to conduct a preliminary investigation of possible routes of entry of VREF into broiler houses and to follow the dynamics of VREF shed by growing birds. A series of nine visits were made to two of six houses on a conventional broiler farm. A total of 343 vanA VREF were recovered from environmental (95/843) and faecal (248/416) samples. Significant differences were observed in the carryover of VREF between pre- and postcohort postcleaning and disinfection visits (RR 0.57, P=0.006). Ninety-nine percent of the VREF isolates were resistant to more than five antimicrobials, with 42 isolates (n=49) positive for erm(B) and 32 (n=40) for vat(E). Pulsed field gel electrophoresis (PFGE) typing identified 50 PFGE types within 15 different PFGE clusters of 90% similarity, demonstrating a high level of genetic diversity within VREF populations from epidemiologically related broiler flocks and broiler houses. Further characterization of Tn1546 from different clones showed a low diversity of Tn-types, suggesting horizontal transfer of resistance determinants between different genetic clones. Thus, this study does not only show the persistence of VREF but also of multi-drug resistant lineages of VREF.