Dissemination of NDM-1 positive bacteria in the New Delhi environment and its implications for human health: an environmental point prevalence study
Dissemination of NDM-1 positive bacteria in the New Delhi environment and its implications for human health: an environmental point prevalence study
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DOI：
10.1016/s1473-3099(11)70059-7
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发表时间：
2011-05-01
影响因子：
56.3
通讯作者：
Toleman, Mark A.
中科院分区：
文献类型：
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作者：
Walsh, Timothy R.;Weeks, Janis;Toleman, Mark A.
背景 并非所有感染 NDM-1 阳性细菌的患者都有印度住院史，并且已知超广谱 β-内酰胺酶在印度社区中流行。因此，我们测量了新德里饮用水和渗漏样品中 NDM-1 基因的流行率。 方法 从新德里市中心 12 公里半径范围内的地点收集了吸收约 100 μL 渗漏水（即街道或溪流中的水池）的拭子和 15 mL 公共自来水样本，并对每个地点进行拍照和记录。样本被运送到英国，并通过 PCR 和 DNA 探测检测 NDM-1 基因 bla(NDM-1) 的存在。作为对照组，从威尔士特雷莫法的卡迪夫废水处理厂采集了 100 微升污水样本。回收所有样品中的细菌并通过 PCR 和测序检查 bla(NDM-1)。我们鉴定了 NDM-1 阳性分离株，进行了药敏试验，并在适当的情况下对分离株进行了分型。我们对 bla(NDM-1) 阳性质粒进行了 Inc 分型。创建转接合子以评估质粒转移频率及其与温度的关系。 结果从2010年9月26日至10月10日，收集了来自新德里的171份渗漏样品和50份自来水样品以及来自卡迪夫废水处理厂的70份污水样品。我们在新德里的 50 个饮用水样本中的 2 个和 171 个渗漏样本中的 51 个中检测到了 bla(NDM-1)；在卡迪夫的任何样本中均未发现该基因。含有 bla(NDM-1) 的细菌是从 171 个渗漏样品中的 12 个和 50 个水样中的 2 个中培养出来的，其中包括 11 个以前未报道过 NDM-1 的细菌，包括博伊迪志贺氏菌和霍乱弧菌。肠杆菌、气单胞菌和霍乱弧菌的携带是稳定的，通常是可传播的，并且与 NDM-1 典型的耐药模式相关；在许多情况下，非发酵菌的运输不稳定，并且与典型的抗性无关。样本中发现了20株细菌，其中12株携带bla(NDM-1)质粒，质粒大小为140至400 kb。豚鼠气单胞菌和霍乱弧菌的分离株在染色体上携带 bla(NDM-1)。接合转移在 30 摄氏度下比在 25 摄氏度或 37 摄氏度下更为常见。 解释 新德里环境样本中存在产生 NDM-1 β-内酰胺酶的细菌，这对于居住在该市依赖公共供水和卫生设施的人们具有重要意义。需要优先考虑国际耐药性监测，包括环境采样以及临床分离株检查。
Background Not all patients infected with NDM-1-positive bacteria have a history of hospital admission in India, and extended-spectrum beta-lactamases are known to be circulating in the Indian community. We therefore measured the prevalence of the NDM-1 gene in drinking water and seepage samples in New Delhi.Methods Swabs absorbing about 100 mu L of seepage water (ie, water pools in streets or rivulets) and 15 mL samples of public tap water were collected from sites within a 12 km radius of central New Delhi, with each site photographed and documented. Samples were transported to the UK and tested for the presence of the NDM-1 gene, bla(NDM-1), by PCR and DNA probing. As a control group, 100 mu L sewage effluent samples were taken from the Cardiff Wastewater Treatment Works, Tremorfa, Wales. Bacteria from all samples were recovered and examined for bla(NDM-1) by PCR and sequencing. We identified NDM-1-positive isolates, undertook susceptibility testing, and, where appropriate, typed the isolates. We undertook Inc typing on bla(NDM-1)-positive plasmids. Transconjugants were created to assess plasmid transfer frequency and its relation to temperature.Findings From Sept 26 to Oct 10, 2010, 171 seepage samples and 50 tap water samples from New Delhi and 70 sewage effluent samples from Cardiff Wastewater Treatment Works were collected. We detected bla(NDM-1) in two of 50 drinking-water samples and 51 of 171 seepage samples from New Delhi; the gene was not found in any sample from Cardiff. Bacteria with bla(NDM-1) were grown from 12 of 171 seepage samples and two of 50 water samples, and included 11 species in which NDM-1 has not previously been reported, including Shigella boydii and Vibrio cholerae. Carriage by enterobacteria, aeromonads, and V cholera was stable, generally transmissible, and associated with resistance patterns typical for NDM-1; carriage by non-fermenters was unstable in many cases and not associated with typical resistance. 20 strains of bacteria were found in the samples, 12 of which carried bla(NDM-1) on plasmids, which ranged in size from 140 to 400 kb. Isolates of Aeromonas caviae and V cholerae carried bla(NDM-1) on chromosomes. Conjugative transfer was more common at 30 degrees C than at 25 degrees C or 37 degrees C.Interpretation The presence of NDM-1 beta-lactamase-producing bacteria in environmental samples in New Delhi has important implications for people living in the city who are reliant on public water and sanitation facilities. International surveillance of resistance, incorporating environmental sampling as well as examination of clinical isolates, needs to be established as a priority.