Background

Population-based sewage surveillance has emerged as a promising approach for studying the prevalence of antibiotic resistance in pathogens.

Aim

To determine the temporal prevalence of cefotaxime-resistant E. coli in sewage from five sewage treatment plants located in Bergen city, to determine whether ESBL- and carbapenemase-producing E. coli are consistently disseminated in the receiving environment through sewage.

Method

A total of 569 cefotaxime-resistant E. coli were isolated over a period of 19 months (August 2020-February 2022) using ECC CHROMagar™ plates from 82 samples, antibiotic sensitivity profiles were determined, using Sensititre™ plates. The draft genome sequences were determined, using Illumina MiSeq-based sequencing. Complete genome sequences were determined, using Oxford Nanopore-based sequencing.

Findings

All 569 strains obtained from influent (n=461) and effluent (n=108) were multidrug-resistant. Most of the sequenced strains (52 out of 61) carried bla_CTX-M-15 (38.5%) and bla_CTX-M-27 (34.6%). The most prevalent sequence types (STs) for ESBL-carrying strains were ST131 (32.8%) and ST38 (21.3%). All CTX-M-27-carrying ST131 strains belonged to clade A or C1, while CTX-M-15-harboring strains were present in all the clades. Five OXA-244-producing ST38 strains, genetically similar to epidemic-causing strains from Western Norway, France and the Netherlands, were isolated only from raw and treated sewage of the treatment plant receiving hospital sewage.

Conclusion

This is the first study showing persistent dissemination of OXA-244-producing ST38 clones through sewage in Norway, demonstrating that hospital sewage is the likely source of OXA-244-producing ST38 clones reaching the receiving environment.

中文翻译：

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2020-2022 年挪威医院污水中引起流行的 OXA-244 产碳青霉烯酶大肠杆菌 ST38 的出现和传播

背景

基于人群的污水监测已成为研究病原体抗生素耐药性流行情况的一种有前途的方法。

目的

确定卑尔根市五个污水处理厂污水中头孢噻肟耐药性大肠杆菌的暂时流行情况，以确定产 ESBL 和碳青霉烯酶的大肠杆菌是否持续通过污水在接收环境中传播。

方法

在 19 个月的时间内（2020 年 8 月至 2022 年 2 月），使用 ECC CHROMagar™ 平板从 82 个样品中分离出总共 569 株头孢噻肟耐药大肠杆菌，并使用 Sensititre™ 平板确定了抗生素敏感性概况。使用基于 Illumina MiSeq 的测序确定了基因组草图序列。使用基于牛津纳米孔的测序确定了完整的基因组序列。

发现

从进水（n=461）和出水（n=108）中获得的所有 569 株菌株均具有多重耐药性。大多数已测序菌株（61 株中的 52 株）携带bla _CTX-M-15 (38.5%) 和bla _CTX-M-27 (34.6%)。携带 ESBL 菌株最常见的序列类型 (ST) 是 ST131 (32.8%) 和 ST38 (21.3%)。所有携带CTX-M-27的ST131菌株属于进化枝A或C1，而携带CTX-M-15的菌株存在于所有进化枝中。5 种产生 OXA-244 的 ST38 菌株在基因上与来自挪威西部、法国和荷兰的流行菌株相似，仅从接收医院污水的处理厂的原污水和处理后的污水中分离出来。

结论

这是第一项显示挪威污水中产生 OXA-244 的 ST38 克隆持续传播的研究，表明医院污水可能是产生 OXA-244 的 ST38 克隆到达接收环境的来源。