Department of Environment and Health, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, 250012, China.
Department of Clinical and Experimental Medicine, Linköping University, 581 85, Linköping, Sweden.
Environ Pollut. 2022 Aug 1;306:119437. doi: 10.1016/j.envpol.2022.119437. Epub 2022 May 7.
To date, carbapenem-resistant Enterobacteriaceae have been found predominantly in clinical settings worldwide. Raoultella belongs to the Enterobacteriaceae family which can cause hospital-acquired infections, and carbapenem-resistant Raoultella spp. (CRR) is sporadically reported in the environment. We investigated the distribution and underlying resistance mechanisms of CRR in a wastewater treatment plant (WWTP) from eastern China between January 2018 and February 2019. A total of 17 CRR were isolated from 324 environmental samples, including Raoultella ornithinolytica (n = 15) and Raoultella planticola (n = 2). The detection of CRR was more frequent in the water inlet compared to anaerobic tank, aerobic tank, sludge thickener, activated sludge, mud cake storage area, and water outlet, and CRR was detected in mud cake stacking area. All CRR were resistant to imipenem, meropenem, ampicillin, piperacillin-tazobactam, cefotaxime, ceftazidime, trimethoprim-sulfamethoxazole and fosfomycin. Four different carbapenemase genes were identified, including bla (n = 13), bla (n = 8), bla (n = 1), bla (n = 1). Interestingly, isolated R. ornithinolytica from the WWTP were closely related to those reported from human samples in China. Plasmid analysis indicated that IncFII(Yp), IncP6, and IncU mediated bla spread, IncX3 and IncN2 mediated bla spread in the environment. The core structure of the Tn3-ISKpn27-bla-ISKpn6, ISAba125-bla-ble-trpF-dsbD were identified. The study provides evidence that Raoultella spp. may spread alarming carbapenem resistance in the environment and, therefore, the continuous surveillance for carbapenem resistance in the WWTP should be conducted, especially sludge.
迄今为止，耐碳青霉烯肠杆菌科主要在全球的临床环境中发现。鲁氏菌属属于肠杆菌科，可引起医院获得性感染，而耐碳青霉烯鲁氏菌属（CRR）在环境中则偶有报道。本研究于 2018 年 1 月至 2019 年 2 月期间，调查了来自中国东部的一家污水处理厂（WWTP）中 CRR 的分布和潜在的耐药机制。从 324 个环境样本中分离出 17 株 CRR，包括鸟氨酸罗伊氏菌（n = 15）和植物罗伊氏菌（n = 2）。与厌氧罐、好氧罐、污泥浓缩池、活性污泥、污泥饼储存区和出水口相比，进水口处 CRR 的检出频率更高，且在污泥饼堆积区也有检出。所有 CRR 均对亚胺培南、美罗培南、氨苄西林、哌拉西林-他唑巴坦、头孢噻肟、头孢他啶、复方磺胺甲噁唑和磷霉素耐药。共鉴定出 4 种不同的碳青霉烯酶基因，包括 bla（n = 13）、bla（n = 8）、bla（n = 1）和 bla（n = 1）。有趣的是，从 WWTP 中分离出的鸟氨酸罗伊氏菌与中国人体样本中报道的菌株密切相关。质粒分析表明，IncFII(Yp)、IncP6 和 IncU 介导 bla 传播，IncX3 和 IncN2 介导 bla 在环境中的传播。Tn3-ISKpn27-bla-ISKpn6、ISAba125-bla-ble-trpF-dsbD 的核心结构被鉴定。该研究提供了证据表明，鲁氏菌属可能在环境中传播令人警惕的碳青霉烯类耐药性，因此应持续监测 WWTP 中的碳青霉烯类耐药性，特别是污泥。
