Department of Infection, Immunity and Biochemistry, School of Medicine, Cardiff University, Heath Park, Cardiff, UK.
Lancet Infect Dis. 2011 May;11(5):355-62. doi: 10.1016/S1473-3099(11)70059-7. Epub 2011 Apr 7.
Not all patients infected with NDM-1-positive bacteria have a history of hospital admission in India, and extended-spectrum β-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.
Swabs absorbing about 100 μL 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 μL 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.
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°C than at 25°C or 37°C.
The presence of NDM-1 β-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.
European Union.
并非所有感染 NDM-1 阳性细菌的患者都有在印度住院的病史，而且在印度社区中已知存在广谱β-内酰胺酶。因此，我们测量了新德里饮用水和渗水样本中 NDM-1 基因的流行率。
从新德里中心 12 公里半径范围内的各个地点采集了约 100μL 渗水水（即街道或溪流中的水潭）和 15mL 公共自来水样本的拭子，并对每个地点进行了拍照和记录。将样本运送到英国，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 Tremorfa 的加的夫废水处理厂采集了 100μL 污水废水样本。通过 PCR 和测序从所有样本中回收并检查 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。创建了转导子以评估质粒转移频率及其与温度的关系。
2010 年 9 月 26 日至 10 月 10 日，采集了来自新德里的 171 个渗水样本和 50 个自来水样本以及来自加的夫废水处理厂的 70 个污水废水样本。我们在 50 个饮用水样本中的 2 个和新德里的 171 个渗水样本中的 51 个样本中检测到 bla(NDM-1)；在加的夫的任何样本中均未发现该基因。从 171 个渗水样本中的 12 个和 50 个水样中的 2 个样本中培养出具有 bla(NDM-1)的细菌，其中包括以前未报告过 NDM-1 的 11 个物种，包括肖氏志贺菌和霍乱弧菌。肠杆菌、气单胞菌和 V 霍乱的携带通常是稳定的、可传播的，并且与 NDM-1 的典型耐药模式相关；在许多情况下，非发酵菌的携带不稳定，且与典型耐药模式无关。在样本中发现了 20 株细菌，其中 12 株携带 bla(NDM-1)的质粒，大小从 140 到 400kb 不等。气单胞菌和霍乱弧菌的分离株在染色体上携带 bla(NDM-1)。在 30°C 时，共轭转移比 25°C 或 37°C 更常见。
新德里环境样本中存在 NDM-1 产β-内酰胺酶的细菌，这对依赖公共水和卫生设施的城市居民具有重要意义。需要将包括环境采样以及临床分离株检查在内的耐药性国际监测作为优先事项建立起来。
欧盟。
