Bacterial pathogens and community composition in advanced sewage treatment systems revealed by metagenomics analysis based on high-throughput sequencing

• Published in: PloS one Vol. 10; no. 5; p. e0125549
• Main Authors: Lu, Xin, Zhang, Xu-Xiang, Wang, Zhu, Huang, Kailong, Wang, Yuan, Liang, Weigang, Tan, Yunfei, Liu, Bo, Tang, Junying
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 04.05.2015; Public Library of Science (PLoS)
• Subjects: Activated sludge process; Aeromonas hydrophila; Analysis; Bacteria; Bacteria - classification; Bacteria - genetics; Biodiversity; Community composition; Deoxyribonucleic acid; DNA; DNA sequencing; Effluents; Feces; Genes; Genetic aspects; Genetic testing; Health aspects; High-Throughput Nucleotide Sequencing; Klebsiella; Laboratories; Metagenomics; Methods; Molecular Sequence Data; Next-generation sequencing; Oxidation; Pathogenicity; Pathogenicity islands; Pathogens; Proteins; Raw sewage; RNA, Ribosomal, 16S - genetics; Sedimentation & deposition; Sewage - microbiology; Sewage disposal; Sewage treatment; Sewage treatment plants; Sludge; Studies; Virulence; Virulence (Microbiology); Virulence factors; Virulence Factors - genetics; Waste treatment; Wastewater treatment; Water treatment; Japan; China
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0125549

This study used 454 pyrosequencing, Illumina high-throughput sequencing and metagenomic analysis to investigate bacterial pathogens and their potential virulence in a sewage treatment plant (STP) applying both conventional and advanced treatment processes. Pyrosequencing and Illumina sequencing consistently demonstrated that Arcobacter genus occupied over 43.42% of total abundance of potential pathogens in the STP. At species level, potential pathogens Arcobacter butzleri, Aeromonas hydrophila and Klebsiella pneumonia dominated in raw sewage, which was also confirmed by quantitative real time PCR. Illumina sequencing also revealed prevalence of various types of pathogenicity islands and virulence proteins in the STP. Most of the potential pathogens and virulence factors were eliminated in the STP, and the removal efficiency mainly depended on oxidation ditch. Compared with sand filtration, magnetic resin seemed to have higher removals in most of the potential pathogens and virulence factors. However, presence of the residual A. butzleri in the final effluent still deserves more concerns. The findings indicate that sewage acts as an important source of environmental pathogens, but STPs can effectively control their spread in the environment. Joint use of the high-throughput sequencing technologies is considered a reliable method for deep and comprehensive overview of environmental bacterial virulence.