Free-living bacteria and potential bacterial pathogens in sewage treatment plants
To comprehensively understand the profile of free-living bacteria and potential bacterial pathogens in sewage treatment plants (STPs), this study applied high-throughput sequencing-based metagenomics approaches to investigate the effects of activated sludge (AS) treatment process and ultraviolet (UV) disinfection on the community of bacterial pathogens in two full-scale STPs. A total of 23 bacterial genera were identified as free-living bacteria, and 243 species/OTU97% were identified as potential bacterial pathogens, 6 of which were confidently detected in the STPs (with the total abundances ranging from 0.02 to 14.19%). Both diversity and relative abundance of the detected bacterial pathogens decreased obviously after AS treatment process (p < 0.05), and increased slightly after sedimentation (p < 0.05). UV disinfection shows no obvious effects on the total relative abundance of the free-living pathogenic bacteria in sewage. Although large amounts of the particle-bound pathogens were eliminated through the sewage treatment process, the STPs could not effectively remove the free-living bacterial pathogens, and some pathogenic bacteria (e.g., Pseudomonas aeruginosa) present in the effluent had higher relative abundance after UV disinfection. Overall, the results extend our knowledge regarding the community of potential pathogens (especially free-living pathogens) in STPs.
KeywordsPathogenic bacteria Free-living bacteria Sewage treatment plant Metagenomic analysis Network analysis
Dr. Y. Mao wishes to appreciate the financial support of the Natural Science Foundation of Guangdong (2017A030313315), Shenzhen Science & Technology Projects (JCYJ20160520165135743, ZDSYS201606061530079), and the National Science Foundation of Shenzhen University (Grant Nos. 827-000223 and 2016008).
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
This article does not contain any studies with human participants or animals performed by any of the authors.
- Benjamini Y, Hochberg Y (1995) Controlling the false discovery rate: a practical and powerful approach to multiple testing. J R Stat Soc Ser B Methodol 57(1):289–300Google Scholar
- Caporaso JG, Kuczynski J, Stombaugh J, Bittinger K, Bushman FD, Costello EK, Fierer N, Pena AG, Goodrich JK, Gordon JI, Huttley GA, Kelley ST, Knights D, Koenig JE, Ley RE, Lozupone CA, McDonald D, Muegge BD, Pirrung M, Reeder J, Sevinsky JR, Tumbaugh PJ, Walters WA, Widmann J, Yatsunenko T, Zaneveld J, Knight R (2010) QIIME allows analysis of high-throughput community sequencing data. Nat Methods 7(5):335–336. https://doi.org/10.1038/nmeth.f.303 CrossRefPubMedPubMedCentralGoogle Scholar
- Cheng H-WA, Lucy FE, Broaders MA, Mastitsky SE, Chen C-H, Murray A (2012) Municipal wastewater treatment plants as pathogen removal systems and as a contamination source of noroviruses and Enterococcus faecalis. J Water Health 10(3):380–389. https://doi.org/10.2166/wh.2012.138 CrossRefPubMedGoogle Scholar
- Csardi G, Nepusz T (2006) The igraph software package for complex network research. Int J Compl Syst 1695(5):1–9Google Scholar
- Fouts DE, Matthias MA, Adhikarla H, Adler B, Amorim-Santos L, Berg DE, Bulach D, Buschiazzo A, Chang Y-F, Galloway RL (2016) What makes a bacterial species pathogenic?: comparative genomic analysis of the genus Leptospira. PLoS Negl Trop Dis 10(2):e0004403. https://doi.org/10.1371/journal.pntd.0004403 CrossRefPubMedPubMedCentralGoogle Scholar
- Haas BJ, Gevers D, Earl AM, Feldgarden M, Ward DV, Giannoukos G, Ciulla D, Tabbaa D, Highlander SK, Sodergren E (2011) Chimeric 16S rRNA sequence formation and detection in Sanger and 454-pyrosequenced PCR amplicons. Genome Res 21(3):494–504. https://doi.org/10.1101/gr.112730.110 CrossRefPubMedPubMedCentralGoogle Scholar
- Hahn MW, Scheuerl T, Jezberová J, Koll U, Jezbera J, Šimek K, Vannini C, Petroni G, Wu QL (2012) The passive yet successful way of planktonic life: genomic and experimental analysis of the ecology of a free-living Polynucleobacter population. PLoS One 7(3):e32772. https://doi.org/10.1371/journal.pone.0032772 CrossRefPubMedPubMedCentralGoogle Scholar
- Hassen A, Kallali H, Jedidi N, Annabi M, Ennabli M, Boudabous A (1997) Disinfection of wastewaters by UV irradiation in a semi-industrial pilot plant: effect of UV doses on Pseudomonas aeruginosa. Vecteur Environ 30(1):77–81Google Scholar
- Hassen A, Mahrouk M, Ouzari H, Cherif M, Boudabous A, Damelincourt JJ (2000) UV disinfection of treated wastewater in a large-scale pilot plant and inactivation of selected bacteria in a laboratory UV device. Bioresour Technol 74(2):141–150. https://doi.org/10.1016/S0960-8524(99)00179-0 CrossRefGoogle Scholar
- Lu X, Zhang X-X, Wang Z, Huang K, Wang Y, Liang W, Tan Y, Liu B, Tang J (2015) Bacterial pathogens and community composition in advanced sewage treatment systems revealed by metagenomics analysis based on high-throughput sequencing. PLoS One 10(5):e0125549. https://doi.org/10.1371/journal.pone.0125549 CrossRefPubMedPubMedCentralGoogle Scholar
- Malic S, Hill KE, Hayes A, Percival SL, Thomas DW, Williams DW (2009) Detection and identification of specific bacteria in wound biofilms using peptide nucleic acid fluorescent in situ hybridization (PNA FISH). Microbiology 155(8):2603–2611. https://doi.org/10.1099/mic.0.028712-0 CrossRefPubMedGoogle Scholar
- Milici M, Vital M, Tomasch J, Badewien TH, Giebel HA, Plumeier I, Wang H, Pieper DH, Wagner-Döbler I, Simon M (2017) Diversity and community composition of particle-associated and free-living bacteria in mesopelagic and bathypelagic Southern Ocean water masses: evidence of dispersal limitation in the Bransfield Strait. Limnol Oceanogr 62(3):1080–1095. https://doi.org/10.1002/lno.10487 CrossRefGoogle Scholar
- Mukherjee S, Seshadri R, Varghese NJ, Eloe-Fadrosh EA, Meier-Kolthoff JP, Goker M, Coates RC, Hadjithomas M, Pavlopoulos GA, Paez-Espino D, Yoshikuni Y, Visel A, Whitman WB, Garrity GM, Eisen JA, Hugenholtz P, Pati A, Ivanova NN, Woyke T, Klenk HP, Kyrpides NC (2017) 1,003 reference genomes of bacterial and archaeal isolates expand coverage of the tree of life. Nat Biotechnol 35(7):676–683. https://doi.org/10.1038/nbt.3886 CrossRefPubMedGoogle Scholar
- Munguia-Fragozo P, Alatorre-Jacome O, Rico-Garcia E, Torres-Pacheco I, Cruz-Hernandez A, Ocampo-Velazquez RV, Garcia-Trejo JF, Guevara-Gonzalez RG (2015) Perspective for aquaponic systems: “omic” technologies for microbial community analysis. Biomed Res Int 2015:480386CrossRefPubMedPubMedCentralGoogle Scholar
- Savichtcheva O, Okabe S (2006) Alternative indicators of fecal pollution: relations with pathogens and conventional indicators, current methodologies for direct pathogen monitoring and future application perspectives. Water Res 40(13):2463–2476. https://doi.org/10.1016/j.watres.2006.04.040 CrossRefPubMedGoogle Scholar
- Schloss PD, Westcott SL, Ryabin T, Hall JR, Hartmann M, Hollister EB, Lesniewski RA, Oakley BB, Parks DH, Robinson CJ, Sahl JW, Stres B, Thallinger GG, Van Horn DJ, Weber CF (2009) Introducing mothur: open-source, platform-independent, community-supported software for describing and comparing microbial communities. Appl Environ Microbiol 75(23):7537–7541. https://doi.org/10.1128/AEM.01541-09 CrossRefPubMedPubMedCentralGoogle Scholar
- Tao W, Zhang X-X, Zhao F, Huang K, Ma H, Wang Z, Ye L, Ren H (2016) High levels of antibiotic resistance genes and their correlations with bacterial community and mobile genetic elements in pharmaceutical wastewater treatment bioreactors. PLoS One 11(6):e0156854. https://doi.org/10.1371/journal.pone.0156854 CrossRefPubMedPubMedCentralGoogle Scholar
- Wells C, Wilkins T (1996) Clostridia: spore forming anaerobic Bacilli. In: Baron S (ed) Baron’s medical microbiology, 4th edn. University of Texas Medical Branch, TexasGoogle Scholar
- WHO (2011) Guidelines for drinking-water quality: microbial aspects, 4th edn. Geneva. http://whqlibdoc.who.int/publications/2011/9789241548151_eng.pdf. Accessed 19 Aug 2015
- Woolhouse M, Gowtage-Sequeria S, Evans B (2015) T16: quantitative analysis of the characteristics of emerging and re-emerging human pathogens. Centre for Infectious Diseases, University of Edinburgh. http://webarchive.nationalarchives.gov.uk/20121212135622/http://www.bis.gov.uk/assets/foresight/docs/infectious-diseases/t16.pdf. Accessed 25 July 2015