scholarly journals A mixed blessing of viruses in wastewater treatment plants

2021 ◽  
Author(s):  
Ling-Dong Shi ◽  
Xiyang Dong ◽  
Zongbao Liu ◽  
Yuchun Yang ◽  
Jih-Gaw Lin ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Antibiotic Resistance Genes ◽  
Pollutant Removal ◽  
Positive Role ◽  
Biochemical Processes ◽  
Mixed Blessing ◽  
Multiple Drugs

Activated sludge of wastewater treatment plants harbors a very high diversity of both microorganisms and viruses, wherein the latter control microbial dynamics and metabolisms by infection and lysis of cells. However, it remains poorly understood how viruses impact the biochemical processes of activated sludge, for example in terms of treatment efficiency and pollutant removal. Using metagenomic and metatranscriptomic deep sequencing, the present study recovered thousands of viral sequences from activated sludge samples of three conventional wastewater treatment plants. Gene-sharing network indicated that most of viruses could not be assigned to known viral genera, implying activated sludge as an underexplored reservoir for new viruses and viral diversity. in silico Predictions of virus-host linkages demonstrated that infected microbial hosts, mostly belonging to bacteria, were transcriptionally active and able to hydrolyze polymers including starches, celluloses, and proteins. Some viruses encode auxiliary metabolic genes (AMGs) involved in carbon, nitrogen, and sulfur cycling, and antibiotic resistance genes (ARGs) for resistance to multiple drugs. The former group of virus-encoded genes (i.e. AMGs) may enhance the biodegradation of contaminants like starches and celluloses, suggesting a positive role for viruses in strengthening the performance of activated sludge. However, the latter group (i.e. ARGs) would be disseminated to different microorganisms using viruses as gene shuttles, demonstrating the possibility for viruses to facilitate the spread of antibiotic resistance in the environment. Collectively, this study highlights the mixed blessing of viruses in wastewater treatment plants, and deciphers how they manipulate the biochemical processes in the activated sludge, with implications for both environmental protection and ecosystem security.

scholarly journals Metagenomic Profiles of Antibiotic Resistance Genes in Activated Sludge, Dewatered Sludge and Bioaerosols

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1516
Author(s):  
Il Han ◽  
Keunje Yoo
Keyword(s):  
Antibiotic Resistance ◽  
Wastewater Treatment ◽  
Activated Sludge ◽  
Resistance Genes ◽  
Wastewater Treatment Plants ◽  
Antibiotic Resistance Genes ◽  
Illumina Hiseq ◽  
Wastewater Treatment Process ◽  
Dewatered Sludge ◽  
Scientific Attention

Wastewater treatment plants (WWTPs) have been considered hotspots for the development and dissemination of antibiotic resistance in the environment. Although researchers have reported a significant increase in bioaerosols in WWTPs, the associated bacterial taxa, antibiotic resistance genes (ARGs), and mobile genetic elements (MGEs) remain relatively unknown. In this study, we have investigated the abundance and occurrences of ARGs and MGEs, as well as the bacterial community compositions in activated sludge (AS), dewatered sludge (DS) and bioaerosols (BA) in a WWTP. In total, 153 ARG subtypes belonging to 19 ARG types were identified by the broad scanning of metagenomic profiles obtained using Illumina HiSeq. The results indicated that the total occurrences and abundances of ARGs in AS and DS samples were significantly higher than those in BA samples (p < 0.05). However, some specific ARG types related to sulfonamide, tetracycline, macrolide resistance were present in relatively high abundance in BA samples. Similar to many other full-scale WWTPs, the Proteobacteria (58%) and Bacteroidetes (18%) phyla were dominant in the AS and DS samples, while the Firmicutes (25%) and Actinobacteria (20%) phyla were the most dominant in the BA samples. Although the abundance of genes related to plasmids and integrons in bioaerosols were two to five times less than those in AS and DS samples, different types of MGEs were observed in BA samples. These results suggest that comprehensive analyses of resistomes in BA are required to better understand the emergence of both ARGs and MGEs in the wastewater treatment process due to the significant increase of scientific attention toward bioaerosols effects.

scholarly journals Quantitative Occurrence of Antibiotic Resistance Genes among Bacterial Populations from Wastewater Treatment Plants Using Activated Sludge

2019 ◽  
Vol 9 (3) ◽  
pp. 387 ◽  
Author(s):  
Adriana Osińska ◽  
Ewa Korzeniewska ◽  
Monika Harnisz ◽  
Sebastian Niestępski
Keyword(s):  
Antibiotic Resistance ◽  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Antibiotic Resistance Gene ◽  
Antibiotic Resistance Genes ◽  
Treated Wastewater ◽  
Beta Lactams ◽  
Treatment Technology ◽  
Bacterial Populations

Wastewater treatment plants (WWTPs) are an important reservoir in the development of drug resistance phenomenon and they provide a potential route of antibiotic resistance gene (ARGs) dissemination in the environment. The aim of this study was to assess the role of WWTPs in the spread of ARGs. Untreated and treated wastewater samples that were collected from thirteen Polish WWTPs (applying four different modifications of activated sludge–based treatment technology) were analyzed. The quantitative occurrence of genes responsible for the resistance to beta-lactams and tetracyclines was determined using the real-time PCR method. Such genes in the DNA of both the total bacterial population and of the E. coli population were analyzed. Among the tested genes that are responsible for the resistance to beta-lactams and tetracyclines, blaOXA and blaTEM and tetA were dominant, respectively. This study found an insufficient reduction in the quantity of the genes that are responsible for antibiotic resistance in wastewater treatment processes. The results emphasize the need to monitor the presence of genes determining antibiotic resistance in the wastewater that is discharged from treatment plants, as they can help to identify the hazard that treated wastewater poses to public health.

scholarly journals Metagenomic Community Composition and Resistome Analysis in a Full-scale Cold Climate Wastewater Treatment Plant

2021 ◽  
Author(s):  
Miguel Uyaguari
Keyword(s):  
Antibiotic Resistance ◽  
Wastewater Treatment ◽  
Activated Sludge ◽  
Relative Abundance ◽  
Resistance Genes ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Antibiotic Resistance Genes ◽  
Gene Copies ◽  
Final Effluent

Abstract Background: Wastewater treatment plants are an essential part of maintaining the health and safety of the general public. However, they are also an anthropogenic source of antibiotic resistance genes. In this study, we characterized the resistome, the distribution of classes 1-3 integron-integrase genes (intI1, intI2, and intI3) as mobile genetic element biomarkers, and the bacterial and phage community compositions in the North End Sewage Treatment Plant in Winnipeg, Manitoba. Samples were collected from raw sewage, returned activated sludge, final effluent, and dewatered sludge. A total of 28 bacterial and viral metagenomes were sequenced over two seasons, fall and winter. Integron-integrase genes, the 16S rRNA gene, and the coliform beta-glucuronidase gene were also quantified during this time period. Results: Bacterial classes observed above 1% relative abundance in all treatments were Actinobacteria (39.24% ± 0.25%), Beta-proteobacteria (23.99% ± 0.16%), Gamma-proteobacteria (11.06% ± 0.09%), and Alpha-proteobacteria (9.18 ± 0.04%). Families within the Caudovirales order: Siphoviridae (48.69% ± 0.10%), Podoviridae (23.99% ± 0.07%), and Myoviridae (19.94% ± 0.09%) were the dominant phage observed throughout the NESTP. The most abundant bacterial genera (in terms of average percent relative abundance) in influent, returned activated sludge, final effluent, and sludge, respectively, includes Mycobacterium (37.4%, 18.3%, 46.1%, and 7.7%), Acidovorax (8.9%, 10.8%, 5.4%, and 1.3%), and Polaromonas (2.5%, 3.3%, 1.4%, and 0.4%).The most abundant class of antibiotic resistance in bacterial samples was tetracycline resistance (17.86% ± 0.03%) followed by peptide antibiotics (14.24% ± 0.03%), and macrolides (10.63% ± 0.02%). Similarly, the phage samples contained a higher prevalence of macrolide (30.12% ± 0.30%), peptide antibiotic (10.78% ± 0.13%), and tetracycline (8.69% ± 0.11%) resistance. In addition, intI1 was the most abundant integron-integrase gene throughout treatment (1.14x104 gene copies/mL) followed by intI3 (4.97x103 gene copies/mL) while intI2 abundance remained low (6.4x101 gene copies/mL).Conclusions: The wastewater treatment plant successfully reduced the abundance of bacteria, DNA bacteriophages, and antibiotic resistance genes although many of them still remained in effluent and biosolids. The presence of integron-integrase genes throughout treatment and in effluent suggests that antibiotic resistance genes could be actively disseminating resistance between both environmental and pathogenic bacteria.

scholarly journals Drug resistance in airborne bacteria isolated from waste management and wastewater treatment plants in Olsztyn

2019 ◽  
Vol 100 ◽  
pp. 00066 ◽  
Author(s):  
Jacek Potorski ◽  
Izabela Koniuszewska ◽  
Małgorzata Czatzkowska ◽  
Monika Harnisz
Keyword(s):  
Antibiotic Resistance ◽  
Wastewater Treatment ◽  
Waste Management ◽  
Wastewater Treatment Plants ◽  
Antibiotic Resistance Genes ◽  
Resistant Bacteria ◽  
Bacterial Strains ◽  
Bacterial Counts ◽  
Air Samples ◽  
Processing Line

Wastewater treatment plants (WWTPs) and municipal waste management plants (MWMPs) emit bioaerosols containing potentially pathogenic biological components which post a threat for human health. Microbiological monitoring supports evaluations of the antibiotic resistance (AR) of airborne microorganisms and the relevant health risks. The aim of this study was to analyze the microbiological quality of air sampled in a WWTP and MWMP in Olsztyn based on total bacterial counts, the presence of bacteria resistant to three antibiotic classes (beta-lactams, tetracyclines and chloramphenicol) and genes encoding resistance to these antibiotics (blaTEM, blaSHV, blaCMY-2, blaAmpC, tet(M), tet(A), tet(X), tet(B), cmlA, floR, fexA, fexB and catA1 ). Bacterial counts were higher in air samples collected from the MWMP (~104 CFU/m3) than from the WWTP (101–103 CFU/m3). A similar trend was noted in the counts of antibiotic resistant bacteria (ARB). The abundance of ARB did not exceed 1.7 x 102 CFU/m3 in WWTP samples, but was higher at up to 4.2 x 103 CFU/m3 in MWMP samples. Bacteria resistant to doxycycline were least prevalent in the analyzed ARB. In the group of 49 tested bacterial strains, 44 harbored at least one of the analyzed antibiotic resistance genes (ARGs). A comparison of ARGs in all bacterial strains isolated from WWTP and MWMP air samples revealed the highest diversity and prevalence of ARGs in the samples collected in the mechanical segment of the waste processing line in MWMP and the biological segment of the wastewater processing line in WWTP. The results of this study point to high microbiological contamination of air in MWMPs and WWTPs which are reservoirs of ARB and ARGs and potential sources of AR.

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