Wang Di, Berglund Björn, Li Qi, Shangguan Xiaorong, Li Jingjing, Liu Feng, Yao Fanghui, Li Xuewen
Department of Environment and Health, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, 250012, China.
Department of Cell and Molecular Biology, Uppsala University, 751 24, Uppsala, Sweden.
Environ Pollut. 2023 Nov 1;336:122455. doi: 10.1016/j.envpol.2023.122455. Epub 2023 Aug 24.
Carbapenem-resistant Enterobacterales (CRE) constitute an urgent threat to worldwide public health. The spread of CRE is facilitated by transmission via the environment. Wastewater treatment plants (WWTPs) are considered to be important sources of antibiotic resistance and hot spots of antibiotic-resistant bacteria (ARB) which can facilitate dissemination of antibiotic resistance genes. In this study, water samples were collected over one year from a WWTP in Jinan, Shandong province, China, from different functional sites in the wastewater treatment process. Carbapenem-resistant Escherichia coli (CREC) were isolated by selective cultivation and whole-genome sequenced to investigate the occurrence and characteristics of CREC in the WWTP. A total of 77 CREC isolates were included in the study and the detection rate of CREC in the WWTP water inlet was found to be 85%. An additional 10 CREC were isolated from a nearby teaching hospital during the sampling period and included for comparison to the environmental isolates. Susceptibility testing showed that all CREC were multidrug-resistant. 6 different carbapenem resistance genes (CRGs) were detected, including bla (n = 75), bla (n = 6), bla (n = 3), bla (n = 1), bla (n = 1), and bla (n = 4). 42 CREC isolates were whole-genome sequenced with Illumina short-read sequencing. 11 of these were also sequenced with Nanopore long-read sequencing. Plasmids carrying CRGs were found to belong to IncX3 (n = 35), IncFII (n = 12), IncFIA (n = 5), IncFIB (n = 2), IncC (n = 1), and IncP6 (n = 1). Clonal dissemination of CREC belonging to ST167, ST448, and ST746 was observed between different parts of the WWTP. Furthermore, isolates from the WWTP, including an isolate belonging to the high-risk ST167 strain, were found to be clonally related to CREC isolated at the hospital. The spread of CRGs is of considerable concern and strategies to prevent environmental dissemination of this contaminant urgently needs to be implemented.
耐碳青霉烯类肠杆菌科细菌（CRE）对全球公共卫生构成了紧迫威胁。环境传播促进了CRE的扩散。污水处理厂（WWTPs）被认为是抗生素耐药性的重要来源以及抗生素耐药菌（ARB）的热点区域，这些区域可促进抗生素耐药基因的传播。在本研究中，一年内从中国山东省济南市的一座污水处理厂的废水处理过程中的不同功能位点采集水样。通过选择性培养分离出耐碳青霉烯类大肠杆菌（CREC），并对其进行全基因组测序，以研究污水处理厂中CREC的发生情况和特征。该研究共纳入77株CREC分离株，发现污水处理厂进水口的CREC检出率为85%。在采样期间，还从附近一家教学医院分离出另外10株CREC，并纳入与环境分离株进行比较。药敏试验表明，所有CREC均为多重耐药。检测到6种不同的碳青霉烯耐药基因（CRGs），包括bla（n = 75）、bla（n = 6）、bla（n = 3）、bla（n = 1）、bla（n = 1）和bla（n = 4）。42株CREC分离株采用Illumina短读长测序进行全基因组测序。其中11株还采用纳米孔长读长测序进行测序。携带CRGs的质粒属于IncX3（n = 35）、IncFII（n = 12）、IncFIA（n = 5）、IncFIB（n = 2）、IncC（n = 1）和IncP6（n = 1）。在污水处理厂的不同部位观察到属于ST167、ST448和ST746的CREC的克隆传播。此外，发现污水处理厂的分离株，包括一株属于高风险ST167菌株的分离株，与医院分离的CREC存在克隆相关性。CRGs的传播令人高度关注，迫切需要实施防止这种污染物在环境中传播的策略。
