Table_2_Spatiotemporal dissemination of ESBL-producing Enterobacterales in municipal sewer systems: a prospective, longitudinal study in the city of Basel, Switzerland.xlsx

BackgroundThe contribution of community and hospital sources to the transmission of extended-spectrum β-lactamase producing Enterobacterales (ESBL-PE) remains elusive.
AimTo investigate the extent of community dissemination and the contribution of hospitals to the spread of ESBL-PE by exploring their spatiotemporal distribution in municipal wastewater of the central European city of Basel.
MethodsWastewater samples were collected monthly for two consecutive years throughout Basel, Switzerland, including 21 sites across 10 postcode areas of the city collecting either community wastewater (urban sites, n = 17) or community and hospital wastewater (mixed sites, n = 4). Presumptive ESBL-PE were recovered by selective culture methods. Standard methodologies were applied for species identification, ESBL-confirmation, and quantification.
ResultsNinety-five percent (477/504) of samples were positive for ESBL-PE. Among these isolates, Escherichia coli (85%, 1,140/1,334) and Klebsiella pneumoniae (11%, 153/1,334) were most common. They were recovered throughout the sampling period from all postcodes, with E. coli consistently predominating. The proportion of K. pneumoniae isolates was higher in wastewater samples from mixed sites as compared to samples from urban sites, while the proportion of E. coli was higher in samples from urban sites (p = 0.003). Higher numbers of colony forming units (CFUs) were recovered from mixed as compared to urban sites (median 3.2 × 102 vs. 1.6 × 102 CFU/mL). E. coli-counts showed moderate correlation with population size (rho = 0.44), while this correlation was weak for other ESBL-PE (rho = 0.21).
ConclusionESBL-PE are widely spread in municipal wastewater supporting that community sources are important reservoirs entertaining the spread of ESBL-PE. Hospital-influenced abundance of ESBL-PE appears to be species dependent.

背景 社区与医院来源对产超广谱β-内酰胺酶肠杆菌目细菌（extended-spectrum β-lactamase producing Enterobacterales, ESBL-PE）传播的贡献仍尚不明确。
研究目的 本研究以中欧城市巴塞尔的市政污水为研究对象，通过分析其时空分布特征，探究ESBL-PE的社区传播规模及医院在其传播过程中所发挥的作用。
研究方法 本研究在瑞士巴塞尔全市范围内连续两年按月采集污水样本，覆盖该市10个邮区的21个采样点，其中17个为仅收集社区污水的城市采样点（n=17），4个为同时收集社区与医院污水的混合采样点（n=4）。采用选择性培养法分离疑似ESBL-PE菌株，通过标准实验流程完成菌种鉴定、ESBL确认及定量检测。
研究结果 本研究共采集504份污水样本，其中95%（477/504）的样本ESBL-PE检测呈阳性。共分离得到1334株菌株，其中以大肠埃希菌（Escherichia coli, 85%, 1140/1334）和肺炎克雷伯菌（Klebsiella pneumoniae, 11%, 153/1334）最为常见。所有邮区的采样点在整个采样周期内均分离得到上述菌株，且大肠埃希菌始终为优势菌株。混合采样点污水样本中肺炎克雷伯菌的占比高于城市采样点，而城市采样点样本中大肠埃希菌的占比更高（p=0.003）。混合采样点的菌落形成单位（colony forming units, CFUs）检出量高于城市采样点（中位数分别为3.2×10²与1.6×10² CFU/mL）。大肠埃希菌的计数与人口规模呈中度相关（rho=0.44），而其他ESBL-PE菌株的计数与人口规模的相关性较弱（rho=0.21）。
研究结论 ESBL-PE在市政污水中广泛分布，提示社区来源是维持ESBL-PE传播的重要储存库。受医院影响的ESBL-PE丰度差异呈现物种依赖性。