Department of Environmental, Water and Earth Sciences, Tshwane University of Technology, Arcadia Campus, Private BagX680, Pretoria 0001, South Africa.
Department of Life and Consumer Sciences, University of South Africa, Florida Campus, Johannesburg, South Africa.
Sci Total Environ. 2019 Nov 15;691:80-92. doi: 10.1016/j.scitotenv.2019.06.533. Epub 2019 Jul 2.
The emergence and dissemination of infections caused by carbapenem-resistant Klebsiella pneumoniae (CRKP) are of great concern worldwide, as there are limited options for their treatment. Thus, in this study, whole-genome sequencing (WGS) was applied to assess CRKP distribution and dissemination from hospital settings to the aquatic environment in order to identify the extent of the problem. Samples were collected from hospital wastewaters and receiving water bodies. Susceptible K. pneumoniae and CRKP were enumerated and isolated using standard methods. Seventeen CRKP were DNA-sequenced using an Illumina HiSeq X™ platform. De novo assembly and annotation were performed using SPAdes and RAST, respectively. The study analysed antibiotic resistance traits (antibiotic resistant genes, mobile genetic elements, and virulence genes) in CRKP isolates. Although influent of wastewater harboured the highest CRKP, wastewater treatment plants were efficient in reducing the threat. In terms of resistance per matrix, benthic sediment proved to harbour more CRKP (22.88%) versus susceptible K. pneumoniae, as revealed by their resistant quotient analysis, while effluent of wastewaters (4.21%) and water bodies (4.64%) had the lowest CRKP loads. The disseminating CRKP consisted of six sequence types (ST) - ST307 (n = 7), a novel ST3559 (n = 5), ST15 (n = 2), and one isolate of each of ST39, 152 and 298. All CRKP isolates harboured β-lactams (bla and bla), quinolone (oqxA and oqxB) and fosfomycin (fosA) resistance genes as well as virulence genes. This study highlights the dissemination of 'high' importance and novel ST CRKP from hospital wastewater to waterbodies. This is concerning, particularly in the African context where a sizable number of people still rely on direct water resources for household use, including drinking. Further research is needed to systematically track the occurrence and distribution of these bacteria so as to mitigate their threat.
耐碳青霉烯肺炎克雷伯菌（CRKP）引起的感染的出现和传播引起了全球的极大关注，因为它们的治疗选择有限。因此，在这项研究中，我们应用全基因组测序（WGS）来评估医院环境到水生环境中 CRKP 的分布和传播，以确定问题的严重程度。我们从医院废水和受纳水体中采集样本。使用标准方法对敏感肺炎克雷伯菌和 CRKP 进行计数和分离。使用 Illumina HiSeq XTM 平台对 17 株 CRKP 进行 DNA 测序。使用 SPAdes 和 RAST 分别进行从头组装和注释。该研究分析了 CRKP 分离株中的抗生素耐药特性（抗生素耐药基因、移动遗传元件和毒力基因）。尽管废水的进水口携带了最高数量的 CRKP，但废水处理厂在降低威胁方面非常有效。就每种基质的耐药率而言，与敏感肺炎克雷伯菌相比，底栖沉积物中携带的 CRKP 更多（22.88%），这是通过它们的耐药率分析得出的，而废水的出水（4.21%）和水体（4.64%）携带的 CRKP 负荷最低。传播的 CRKP 由六个序列型（ST）组成 - ST307（n=7）、一种新型 ST3559（n=5）、ST15（n=2）和一个 ST39、152 和 298 的分离株。所有 CRKP 分离株均携带β-内酰胺类（bla 和 bla）、喹诺酮类（oqxA 和 oqxB）和磷霉素（fosA）耐药基因以及毒力基因。本研究强调了高重要性和新型 ST CRKP 从医院废水向水体的传播。这令人担忧，特别是在非洲，许多人仍然依赖直接的水资源供家庭使用，包括饮用水。需要进一步研究以系统地跟踪这些细菌的发生和分布，以减轻其威胁。
