Pathogenic and Indigenous Denitrifying Bacteria are Transcriptionally Active and Key Multi-Antibiotic-Resistant Players in Wastewater Treatment Plants

Abstract

The global rise and spread of antibiotic resistance greatly challenge the treatment of bacterial infections. Wastewater treatment plants (WWTPs) harbor and discharge antibiotic resistance genes (ARGs) as environmental contaminants. However, the knowledge gap on the host identity, activity, and functionality of ARGs limits transmission and health risk assessment of the WWTP resistome. Hereby, a genome-centric quantitative metatranscriptomic approach was exploited to realize high-resolution qualitative and quantitative analyses of bacterial hosts of ARGs (i.e., multiresistance, pathogenicity, activity, and niches) in the 12 urban WWTPs. We found that ∼45% of 248 recovered genomes expressed ARGs against multiple classes of antibiotics, among which bacitracin and aminoglycoside resistance genes in Proteobacteria were the most prevalent scenario. Both potential pathogens and indigenous denitrifying bacteria were transcriptionally active hosts of ARGs. The almost unchanged relative expression levels of ARGs in the most resistant populations (66.9%) and the surviving ARG hosts including globally emerging pathogens (e.g., Aliarcobacter cryaerophilus) in treated WWTP effluent prioritize future examination on the health risks related to resistance propagation and human exposure in the receiving environment.

Microeukaryotic gut parasites in wastewater treatment plants: diversity, activity, and removal

“…According to Cai et al [ 42 ], this applies, for instance, to around 80 % of sewage in India. Subsequently, potentially infectious and harmful parasitic microorganisms become widespread and form a threat to public health when present in drinking water, water recreation areas, and aquatic food production systems [ 42 , 73 – 75 ]. Our results clearly show that biomonitoring of wastewater treatment efficiency via molecular methods (“-omics”) can be greatly improved by using primer-independent shotgun approaches to ensure adequate detection of parasitic protists.…”

PCycDB: a comprehensive and accurate database for fast analysis of phosphorus cycling genes

“…Previously, the prediction of other function databases such as integrase, CARD, and BacMet databases is restricted to a high identity cutoff greater than 80% [ 27 , 50 , 56 ]. More recently, N cycling genes were annotated using NCycDB with an 85% identity threshold [ 26 , 57 ]. However, false negatives can be increased at a high cutoff, that is, a considerable proportion of real functional genes would be removed [ 58 ].…”

Using Culture-Enriched Phenotypic Metagenomics for Targeted High-Throughput Monitoring of Clinically-Important Fraction of Beta-Lactam Resistome

“…5). Note that, multi-antibiotic resistance should considerably facilitate the survival and dissemination of their bacterial hosts in environmental systems with anthropogenic stressors (e.g., antibiotics and heavy metals), such as WWTPs 35 . High-quality MAGs, bridging taxonomy information and ARG profiles, also realizes the characterization of potential HGT events, as revealed in this study that distant phylogenetic lineages shared identical beta-lactamase genes.…”