Molecular Analysis for Screening Human Bacterial Pathogens in Municipal Wastewater Treatment and Reuse

Abstract

Effective and sensitive monitoring of human pathogenic bacteria in municipal wastewater treatment is important not only for managing public health risk related to treated wastewater reuse, but also for ensuring proper functioning of the treatment plant. In this study, three different 16S rRNA gene molecular analysis methodologies were employed to screen bacterial pathogens in samples collected at three different stages of an activated sludge plant. Overall bacterial diversity was analyzed using next generation sequencing (NGS) on the Illumina MiSeq platform, as well as PCR-DGGE followed by band sequencing. In addition, a microdiversity analysis was conducted using PCR-DGGE, targeting Escherichia coli. Bioinformatics analysis was performed using QIIME protocol by clustering sequences against the Human Pathogenic Bacteria Database. NGS data were also clustered against the Greengenes database for a genera-level diversity analysis. NGS proved to be the most effective approach screening the sequences of 21 potential human bacterial pathogens, while the E. coli microdiversity analysis yielded one (O157:H7 str. EDL933) out of the two E. coli strains picked up by NGS. Overall diversity using PCR-DGGE did not yield any pathogenic sequence matches even though a number of sequences matched the NGS results. Overall, sequences of Gram-negative pathogens decreased in relative abundance along the treatment train while those of Gram-positive pathogens increased.

Impacts of addition of natural zeolite or a nitrification inhibitor on antibiotic resistance genes during sludge composting

“…1000 times) to the release of ARGs into the environment compared with WWTPs effluent (Munir et al, 2011). Furthermore, antibiotic resistance factors from WWTPs have been demonstrated to be associated with clinical pathogens (Szczepanowski et al, 2009;Kumaraswamy et al, 2014), and HGT in sewage sludge might occur more frequently due to its high bacterial density and diversity of bacterial communities (Su et al, 2015). In China, 6.25 million tons of dry solids were produced in 2013, and total sludge production grew by 13% annually from 2007 to 2013 .…”

Metagenomic analysis of bacterial community composition and antibiotic resistance genes in a wastewater treatment plant and its receiving surface water

“…It is well known that most bacteria in the wastewater, including coliforms, can be removed by the treatment of modern WWTPs. However, the incomplete treatment of recalcitrant bacteria, especially some pathogens and bacteria carrying antibiotic resistance genes (ARGs) will put the receiving surface water at risk (Kumaraswamy et al, 2014;Marti et al, 2013). Owing to their high virulence and rapid airborne or water transmission, bacterial pathogens are disastrous and detrimental for human health (Cai and Zhang, 2013;Ahmed et al, 2014;Gomi et al, 2015).…”

Porous Silicon-Based Biosensors: Towards Real-Time Optical Detection of Target Bacteria in the Food Industry

“…Thus, increasing the reuse of water during food production and processing is an urgent need in the global effort to reduce food waste and improve sustainability56. A significant challenge for the development and operation of water reuse schemes is to ensure water quality and safety via appropriate monitoring techniques789. In particular, because microbiological quality assessment of food and water continues to rely on traditional culture-based techniques (which require at least 24 h to obtain results), real-time or near real-time evaluation of reused water safety remains a challenge1011.…”