The pathogens are potentially dangerous to environment and global public health. As a source as well as a sink, waste water treatment plants (WWTPs) have played important roles in receiving and digesting various human pathogens, and may also discharge them into environment. The purpose of this study was to achieve a comprehensive understanding of the characterization of pathogens in different WWTPs and their relationship with wastewater characteristics and environmental factors.
Triplicated activated sludge samples were collected from aeration tanks of 24 WWTPs located in 10 cities in China. After centrifugation, DNA was extracted, then analyzed using GeoChip4.2. Wastewater characteristics were also measured. Diversity，cluster and Canonical correspondence analysis (CCA) were performed by using R. We focused on 33 concerned pathogens that were reported being present in WWTPs previously (Cai & Zhang 2013).
Results/Conclusions
The signal intensities (SIs) of the 33 pathogens accounted for 0.97-1.15% of the total SIs in each samples. 20 of 33 (60.6%) bacterial pathogens were shared by all 24 WWTPs. Moreover, dominant pathogens of each WWTP were the same. Specifically, Pseudomonas aeruginosa had the largest proportion, followed by Salmonella enterica and Mycobacterium tuberculosis in all WWTPs. The CCA results showed that the pathogenic community variance correlated strongly with latitude, temperature, chemical oxygen demand (COD) and dissolved oxygen content. These findings might be able to give us advice and strategies to control pathogens in WWTPs and even can provide information and early warning about local outbreak of epidemic disease. Moreover, the dominant pathogens should be paid attention, since they were detected with antibiotic genes and consequently present more potential pathogenic risks.
Results of this study provided insights into commonly concerned pathogenic abundance and distribution in geographically different WWTPs and uncovered the relationships between pathogenic community and environmental variables in WWTPs.