Altogether, 89 composite samples of untreated community wastewater were collected from 10 wastewater treatment plants across Finland in 2021-2022. CP E. coli and K. pneumoniae were isolated using selective culture media and identified using MALDI-TOF MS. Antimicrobial susceptibility testing was performed using disk diffusion test and broth microdilution method, and a subset of isolates was characterized using whole-genome sequencing.
CP E. coli was detected in 26 (29.2%) and K. pneumoniae in 25 (28.1%) samples. Among E. coli, the most common sequence type (ST) was ST410 (n = 7/26, 26.9%), while ST359 (n = 4/25, 16.0%) predominated among K. pneumoniae. Globally successful STs were detected in both E. coli (ST410, ST1284, ST167, and ST405) and K. pneumoniae (ST512, ST101, and ST307). K. pneumoniae carbapenemases (KPC) were the most common carbapenemases in both E. coli (n = 11/26, 42.3%) and K. pneumoniae (n = 13/25, 52.0%), yet also other carbapenemases, such as blaNDM-5, blaOXA-48, and blaOXA-181, were detected. We detected isolates harboring similar ST and enzyme type combinations previously linked to clusters in Finland, such as E. coli ST410 with blaKPC-2 and K. pneumoniae ST512 with blaKPC-3.
Our study highlights the presence of clinically relevant strains of CP E. coli and K. pneumoniae in community wastewater. The results indicate that wastewater surveillance could serve as a monitoring tool for CP Enterobacterales. However, the specificity and sensitivity of the methods should be improved, and technologies, like advanced sequencing methods, should be utilized to distinguish data with public health relevance, harness the full potential of wastewater surveillance, and implement the data in public health surveillance.
方法:总之,在2021年至2022年期间,从芬兰的10个污水处理厂收集了89个未经处理的社区废水的复合样品。使用选择性培养基分离CP大肠杆菌和肺炎克雷伯菌,并使用MALDI-TOFMS进行鉴定。使用圆盘扩散试验和肉汤微量稀释法进行抗菌药物敏感性试验,并且使用全基因组测序对分离株的子集进行了表征。
结果:在26个(29.2%)样品中检测到CP大肠杆菌,在25个(28.1%)样品中检测到肺炎克雷伯菌。在大肠杆菌中,最常见的序列类型(ST)是ST410(n=7/26,26.9%),而ST359(n=4/25,16.0%)在肺炎克雷伯菌中占主导地位。在大肠杆菌(ST410、ST1284、ST167和ST405)和肺炎克雷伯菌(ST512、ST101和ST307)中检测到总体上成功的ST。肺炎克雷伯菌碳青霉烯酶(KPC)是大肠杆菌(n=11/26,42.3%)和肺炎克雷伯菌(n=13/25,52.0%)中最常见的碳青霉烯酶,还有其他碳青霉烯酶,检测到例如blaNDM-5、blaOXA-48和blaOXA-181。我们在芬兰检测到具有相似ST和酶类型组合的分离株,例如具有blaKPC-2的大肠杆菌ST410和具有blaKPC-3的肺炎克雷伯菌ST512。
结论:我们的研究强调了社区废水中存在CP大肠杆菌和肺炎克雷伯菌的临床相关菌株。结果表明,废水监测可以作为CP肠杆菌的监测工具。然而,应提高方法的特异性和灵敏度,和技术,像先进的测序方法,应该用来区分与公共卫生相关的数据,充分利用废水监测的潜力,并在公共卫生监测中实施数据。