Differences in pathogenic community assembly processes and their interactions with bacterial communities in river and lake ecosystems

Lei Zhang; Shuqi Fang; Wenqing Hong; Zhen Shen; Shuo Li; Wangkai Fang

doi:10.1016/j.envres.2023.116847

Differences in pathogenic community assembly processes and their interactions with bacterial communities in river and lake ecosystems

Environ Res. 2023 Nov 1;236(Pt 2):116847. doi: 10.1016/j.envres.2023.116847. Epub 2023 Aug 7.

Authors

Lei Zhang¹, Shuqi Fang², Wenqing Hong², Zhen Shen³, Shuo Li², Wangkai Fang⁴

Affiliations

¹ School of Civil Engineering and Architecture, Chuzhou University, Chuzhou, 239000, China. Electronic address: leizhang2014@163.com.
² School of Civil Engineering and Architecture, Chuzhou University, Chuzhou, 239000, China.
³ Nanjing Institute of Geography and Limnology Chinese Academy of Sciences, Nanjing, 210008, China.
⁴ School of Earth and Environment, Anhui University of Science & Technology, Huainan, 232000, China.

PMID: 37558117
DOI: 10.1016/j.envres.2023.116847

Abstract

Pathogenic bacterial infections caused by water quality degradation are one of the most widespread environmental problems. Clarifying the structure of pathogens and their assembly mechanisms in lake ecosystems is vital to prevent the infestation of waterborne pathogens and maintain human health. However, the composition and assembly mechanisms of pathogenic bacterial communities in river and lake ecosystems are still poorly understood. In this study, we collected 17 water and 17 sediment samples from Lake Chaohu and its 11 inflow rivers. Sequencing of 16S rRNA genes was used to study bacterial pathogen communities. The results of the study showed that there was a significant difference (P < 0.05) in the composition of the pathogen community between riverine and lake habitats. Acinetobacter (36.49%) was the dominant bacterium in the river, whereas Flavobacterium (21.6%) was the most abundant bacterium in the lake. Deterministic processes (i.e., environmental filtering and species interaction) drove the assembly of pathogenic bacterial communities in the lake habitat, while stochastic processes shaped river pathogenic bacterial communities. Spearman correlation analysis showed that the α-diversity of bacterial communities was linearly and negatively linked to the relative abundance of pathogens. Having a higher bacterial community diversity had a suppressive effect on pathogen abundance. In addition, co-occurrence network analysis showed that bacterial communities were tightly linked to pathogenic bacteria. Pseudomonas aeruginosa and Salmonella enterica were identified as keystone species in an inflow water sampling network (W_FR), reducing the complexity of the network. These results provide a reference for assessments of water quality safety and pathogenic bacteria posing risks to human health in large freshwater lakes.

Keywords: Assembly mechanism; Co-occurrence network; Pathogenic bacterial community.