Mesquita Elsa, Ribeiro Rita, Silva Carla J C, Alves Rita, Baptista Rita, Condinho Sílvia, Rosa Maria João, Perdigão João, Caneiras Cátia, Duarte Aida
Water Quality and Treatment Laboratory, Urban Water Unit, Hydraulics and Environment Department, The Laboratório Nacional de Engenharia Civil (LNEC)-National Civil Engineering Laboratory, 1700-066 Lisboa, Portugal.
Direção de Operações de Saneamento, ETAR de Beirolas, Rua Chen He, 1990-513 Sacavém, Portugal.
Microorganisms. 2021 Mar 11;9(3):576. doi: 10.3390/microorganisms9030576.
Wastewater treatment plants (WWTPs) are significant reservoirs of bacterial resistance. This work aims to identify the determinants of resistance produced by Gram-negative bacteria in the influent and effluent of two WWTPs in Portugal. A total of 96 wastewater samples were obtained between 2016 and 2019. The numbers of total aerobic and fecal contamination bacteria were evaluated, and genomic features were searched by polymerase chain reaction (PCR) and Next-Generation Sequencing (NGS). corresponded to 78.6% ( = 161) of the 205 isolates identified by 16sRNA. The most frequent isolates were spp. (57.1%, = 117), followed by spp. (16.1%, = 33) and spp. (12.7%, = 26). The remaining 29 isolates (14.1%) were distributed across 10 different genera. Among the 183 resistant genes detected, 54 isolates produced extended spectrum β-lactamases (ESBL), of which was predominant (37 isolates; 68.5%). A KPC-3 carbapenemase-producing was identified ( = 1), with included in a transposon isoform b. A higher number of virulence genes (VG) (19 genes) was found in the 5301 (O25b-ST131-B2) isolate compared with a commensal 5281 (O25b-ST410-A) (six genes). Both shared five VG [Enterobactin; Aerobactin, CFA/1 (clade α); Type1 (clade γ1); Type IV]. In conclusion, this work highlights the role of relevant clinical bacteria in WWTPs, such as KPC-3-producing and, for the first time, a CTX-M-15-producing , a human opportunistic pathogen, and a SED-1-producing , an uncommon CTX-M-type extended-spectrum beta-lactamase.
污水处理厂（WWTPs）是细菌耐药性的重要储存库。这项工作旨在确定葡萄牙两座污水处理厂进水和出水中革兰氏阴性菌产生耐药性的决定因素。2016年至2019年期间共采集了96份废水样本。评估了总需氧菌和粪便污染菌的数量，并通过聚合酶链反应（PCR）和下一代测序（NGS）搜索基因组特征。这相当于通过16sRNA鉴定的205株分离株中的78.6%（n = 161）。最常见的分离株是大肠埃希菌属（57.1%，n = 117），其次是肺炎克雷伯菌属（16.1%，n = 33）和阴沟肠杆菌属（12.7%，n = 26）。其余29株分离株（14.1%）分布在10个不同的属中。在检测到的183个耐药基因中，54株分离株产生超广谱β-内酰胺酶（ESBL），其中CTX-M型为主（37株；68.5%）。鉴定出一株产KPC-3碳青霉烯酶的肺炎克雷伯菌（n = 1），其KPC-3包含在转座子Tn4401亚型b中。与共生的大肠埃希菌5281（O25b-ST410-A）（6个基因）相比，在大肠埃希菌5301（O25b-ST131-B2）分离株中发现了更多的毒力基因（VG）（19个基因）。两者共有5个VG[肠杆菌素；气杆菌素，CFA/1（α分支）；1型（γ1分支）；IV型]。总之，这项工作突出了污水处理厂中相关临床细菌的作用，如产KPC-3的肺炎克雷伯菌，以及首次发现的产CTX-M-15的大肠埃希菌，一种人类机会致病菌，和产SED-1的大肠埃希菌，一种罕见的CTX-M型超广谱β-内酰胺酶。
