Profiling Bacterial Diversity and Potential Pathogens in Wastewater Treatment Plants Using High-Throughput Sequencing Analysis

• Main Authors: Cecilia Oluseyi Osunmakinde, Ramganesh Selvarajan, Bhekie B. Mamba, Titus A.M. Msagati
• Format: Article
• Language: English
• Published: MDPI AG 2019-10-01
• Series: Microorganisms
• Subjects: high-throughput sequencing; bacteria; biodiversity; pathogens; wastewater treatment plant
• Online Access: https://www.mdpi.com/2076-2607/7/11/506

Next-generation sequencing provides new insights into the diversity and structure of bacterial communities, as well as the fate of pathogens in wastewater treatment systems. In this study, the bacterial community structure and the presence of pathogenic bacteria in three wastewater treatment plants across Gauteng province in South Africa were studied. The physicochemical results indicated that the quality of wastewater varies considerably from one plant to the others. <i>Proteobacteria, Actinobacteria, Firmicutes</i>, and <i>Chloroflexi</i> were the dominant phyla across the three wastewater treatment plants, while <i>Alphaproteobacteria</i>, <i>Actinobacteria</i>, <i>Bacilli</i>, and <i>Clostridia</i> were the dominant classes. The dominant bacterial functions were highly associated with carbohydrate, energy, and amino acid metabolism. In addition, potential pathogenic bacterial members identified from the influent/effluent samples included <i>Roseomonas</i>, <i>Bacillus</i>, <i>Pseudomonas</i>, <i>Clostridium</i>, <i>Mycobacterium</i>, <i>Methylobacterium</i>, and <i>Aeromonas</i>. The results of linear discriminant analysis (LDA) effect size analysis also confirmed that these bacterial pathogens were significantly abundant in the wastewater treatment systems. Further, the results of this study highlighted that the presence of bacterial pathogens in treated effluent pose a potential contamination risk, transmitted through soil, agriculture, water, or sediments. There is thus a need for continuous monitoring of potential pathogens in wastewater treatment plants (WWTPs) in order to minimize public health risk.