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Author: Liping Ma
Publisher: Open Dissertation Press
ISBN: 9781361039007
Category : Technology & Engineering
Languages : en
Pages : 272
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Book Description
This dissertation, "Antibiotic Resistance Genes Carried by Microbial Communities in Drinking Water Systems" by Liping, Ma, 馬黎萍, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: The overuse and misuse of antibiotics not only for human therapy but also for livestock breeding have led to the emergence and prosperity of antibiotic resistance genes (ARGs) and antibiotic resistant bacteria (ARB) and attracted great concerns worldwide. Drinking water distribution system (DWDS) considered as important means to remove pathogens for drinking water supply has been discovered as reservoir of ARGs. However, the comprehensive profiles of ARGs distributed in DWDS or the elimination efficiency of ARGs by drinking water treatment process or the hosts of ARGs distributed in DWDS has not been well studied yet. Thus, the major objectives of this study were (1) to reveal the wide-spectrum profiles of ARGs in DWDS; (2) to investigate the elimination efficiency of ARGs using traditional drinking water treatment process; (3) to develop a metagenomic assembly based method for identification of ARG-carrying genomes; (4) to explore the impacts of chlorination treatment on the shift of ARGs among microbial community. To scan for the occurrence, abundance and diversity of ARGs in DWDS, the metagenomic sequencing approach combined with structured ARG database was established. ARGs were found enriched by 81%-109% after traditional drinking water treatment processes, while the diversity of ARGs greatly decreased by 28%-51%. Acridine, chloramphenicol, and polymyxin related ARGs were fully removed during drinking water treatment. A metagenomic assembly based method for identifying ARG-carrying genomes in environmental samples was developed, could be applied to 1) identify host of ARGs, 2) to quantify their abundance in samples based on coverage, 3) to explore the antibiotic resistome shared among bacteria, and 4) to determine the correlations of ARGs with associated genetic elements. Moreover, the broad-spectrum profiles of ARGs were detected in tap water samples collected from six countries or regions, including mainland China, Hong Kong, Macau, Taiwan, South Africa, Singapore and United States, respectively. Totally, 16 ARG types and 183 ARG subtypes were detected. The most dominant ARG types were bacitracin, multidrug and aminoglycoside resistance genes. 8 subtypes were generalists which existed in all samples, including bacitracin undecaprenyl diphosphatase, bacitracin undecaprenol kinase, multidrug efflux protein, multidrug HAE1-family protein, multidrug mexF, beta-lactam TEM-2, macrolide macB, and beta-lactam TEM-15. The culture-based isolation approach combined with antimicrobial susceptibility test and high-throughput sequencing technique revealed that 66.8% ARG subtypes decreased after chlorination treatments, while, only 4.5% ARG subtypes were enriched after chlorination. Tetracycline resistance genes were effectively removed by chlorination treatment (>78%). This study is the first application of high-throughput sequencing technique combined with traditional culture-based isolation approach to detect ARGs of viable microorganisms after chlorination process. The established class 1 integrase database and the assembly of gene cassettes carried by integrons were applied to investigate the abundance of intI1 in diverse environments and the arrangement of gene cassettes. Class 1 integrase intI1 genes were detected at abundance of 0 -1.3 〖10〗 DEGREES(-1)copy of intI1/cellin drinking water samples. Aminoglycoside resistance genes were most frequently
Author: Liping Ma
Publisher: Open Dissertation Press
ISBN: 9781361039007
Category : Technology & Engineering
Languages : en
Pages : 272
Get Book Here
Book Description
This dissertation, "Antibiotic Resistance Genes Carried by Microbial Communities in Drinking Water Systems" by Liping, Ma, 馬黎萍, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: The overuse and misuse of antibiotics not only for human therapy but also for livestock breeding have led to the emergence and prosperity of antibiotic resistance genes (ARGs) and antibiotic resistant bacteria (ARB) and attracted great concerns worldwide. Drinking water distribution system (DWDS) considered as important means to remove pathogens for drinking water supply has been discovered as reservoir of ARGs. However, the comprehensive profiles of ARGs distributed in DWDS or the elimination efficiency of ARGs by drinking water treatment process or the hosts of ARGs distributed in DWDS has not been well studied yet. Thus, the major objectives of this study were (1) to reveal the wide-spectrum profiles of ARGs in DWDS; (2) to investigate the elimination efficiency of ARGs using traditional drinking water treatment process; (3) to develop a metagenomic assembly based method for identification of ARG-carrying genomes; (4) to explore the impacts of chlorination treatment on the shift of ARGs among microbial community. To scan for the occurrence, abundance and diversity of ARGs in DWDS, the metagenomic sequencing approach combined with structured ARG database was established. ARGs were found enriched by 81%-109% after traditional drinking water treatment processes, while the diversity of ARGs greatly decreased by 28%-51%. Acridine, chloramphenicol, and polymyxin related ARGs were fully removed during drinking water treatment. A metagenomic assembly based method for identifying ARG-carrying genomes in environmental samples was developed, could be applied to 1) identify host of ARGs, 2) to quantify their abundance in samples based on coverage, 3) to explore the antibiotic resistome shared among bacteria, and 4) to determine the correlations of ARGs with associated genetic elements. Moreover, the broad-spectrum profiles of ARGs were detected in tap water samples collected from six countries or regions, including mainland China, Hong Kong, Macau, Taiwan, South Africa, Singapore and United States, respectively. Totally, 16 ARG types and 183 ARG subtypes were detected. The most dominant ARG types were bacitracin, multidrug and aminoglycoside resistance genes. 8 subtypes were generalists which existed in all samples, including bacitracin undecaprenyl diphosphatase, bacitracin undecaprenol kinase, multidrug efflux protein, multidrug HAE1-family protein, multidrug mexF, beta-lactam TEM-2, macrolide macB, and beta-lactam TEM-15. The culture-based isolation approach combined with antimicrobial susceptibility test and high-throughput sequencing technique revealed that 66.8% ARG subtypes decreased after chlorination treatments, while, only 4.5% ARG subtypes were enriched after chlorination. Tetracycline resistance genes were effectively removed by chlorination treatment (>78%). This study is the first application of high-throughput sequencing technique combined with traditional culture-based isolation approach to detect ARGs of viable microorganisms after chlorination process. The established class 1 integrase database and the assembly of gene cassettes carried by integrons were applied to investigate the abundance of intI1 in diverse environments and the arrangement of gene cassettes. Class 1 integrase intI1 genes were detected at abundance of 0 -1.3 〖10〗 DEGREES(-1)copy of intI1/cellin drinking water samples. Aminoglycoside resistance genes were most frequently
Author: Liping Ma
Publisher:
ISBN: 9781361039021
Category :
Languages : en
Pages :
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Book Description
This dissertation, "Antibiotic Resistance Genes Carried by Microbial Communities in Drinking Water Systems" by Liping, Ma, 馬黎萍, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: The overuse and misuse of antibiotics not only for human therapy but also for livestock breeding have led to the emergence and prosperity of antibiotic resistance genes (ARGs) and antibiotic resistant bacteria (ARB) and attracted great concerns worldwide. Drinking water distribution system (DWDS) considered as important means to remove pathogens for drinking water supply has been discovered as reservoir of ARGs. However, the comprehensive profiles of ARGs distributed in DWDS or the elimination efficiency of ARGs by drinking water treatment process or the hosts of ARGs distributed in DWDS has not been well studied yet. Thus, the major objectives of this study were (1) to reveal the wide-spectrum profiles of ARGs in DWDS; (2) to investigate the elimination efficiency of ARGs using traditional drinking water treatment process; (3) to develop a metagenomic assembly based method for identification of ARG-carrying genomes; (4) to explore the impacts of chlorination treatment on the shift of ARGs among microbial community. To scan for the occurrence, abundance and diversity of ARGs in DWDS, the metagenomic sequencing approach combined with structured ARG database was established. ARGs were found enriched by 81%-109% after traditional drinking water treatment processes, while the diversity of ARGs greatly decreased by 28%-51%. Acridine, chloramphenicol, and polymyxin related ARGs were fully removed during drinking water treatment. A metagenomic assembly based method for identifying ARG-carrying genomes in environmental samples was developed, could be applied to 1) identify host of ARGs, 2) to quantify their abundance in samples based on coverage, 3) to explore the antibiotic resistome shared among bacteria, and 4) to determine the correlations of ARGs with associated genetic elements. Moreover, the broad-spectrum profiles of ARGs were detected in tap water samples collected from six countries or regions, including mainland China, Hong Kong, Macau, Taiwan, South Africa, Singapore and United States, respectively. Totally, 16 ARG types and 183 ARG subtypes were detected. The most dominant ARG types were bacitracin, multidrug and aminoglycoside resistance genes. 8 subtypes were generalists which existed in all samples, including bacitracin undecaprenyl diphosphatase, bacitracin undecaprenol kinase, multidrug efflux protein, multidrug HAE1-family protein, multidrug mexF, beta-lactam TEM-2, macrolide macB, and beta-lactam TEM-15. The culture-based isolation approach combined with antimicrobial susceptibility test and high-throughput sequencing technique revealed that 66.8% ARG subtypes decreased after chlorination treatments, while, only 4.5% ARG subtypes were enriched after chlorination. Tetracycline resistance genes were effectively removed by chlorination treatment (>78%). This study is the first application of high-throughput sequencing technique combined with traditional culture-based isolation approach to detect ARGs of viable microorganisms after chlorination process. The established class 1 integrase database and the assembly of gene cassettes carried by integrons were applied to investigate the abundance of intI1 in diverse environments and the arrangement of gene cassettes. Class 1 integrase intI1 genes were detected at abundance of 0 -1.3 〖10〗 DEGREES(-1)copy of intI1/cellin drinking water samples. Aminoglycoside resistance genes were most frequently
Author: Stuart B. Levy
Publisher: McGraw-Hill Companies
ISBN:
Category : Science
Languages : en
Pages : 458
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Book Description
Author: Damia Barcelo
Publisher: Springer
ISBN: 364228132X
Category : Science
Languages : en
Pages : 475
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Book Description
This volume provides an overview of the occurrence and fate of emerging contaminants, discusses advanced chemical analysis methods, toxicological and ecotoxicological effects as well as human exposure. One focus is on pharmaceuticals, in particular antibiotics, and the problems associated with their increased use in hospitals. Other covered emerging contaminants occurring e.g. in food, water, air or soil include brominated flame retardants, polar pesticides, phthalates, phosphate esters, perfluorinated compounds, personal care products, musk fragrances, disinfection byproducts, illicit drugs, and nanomaterials. The chapters written by experts are a valuable source of information for a broad audience, such as analytical chemists, environmental chemists and engineers, toxicologists, ecotoxicologists and epidemiologists working already in this field as well as newcomers.
Author: Sadia Khan
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
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Book Description
The drinking-water environment is prone to chemical and biological pollution, and it remains a challenge to achieve contamination-free water for the consumer. Biological contaminants (microorganisms and their genetic traits) can become more difficult to treat, as compared to chemical, as they can escape treatment processes (including disinfection) and replicate. Their presence in the drinking water environment has become considered to be a hotspot for the dissemination of antimicrobial resistance genes (ARG). Moreover, the treatment process may create conditions that may exacerbate the development and dissemination of ARG. The inter-relationship between disinfectant exposure, a common water-treatment process and the development of antibiotic resistance was investigated in this study. Potential human and animal pathogens from municipal drinking water, representing twenty-two genera, were characterized for antibiotic and disinfectant resistances. The co-existence of antibiotic resistant and transferable genes was found in bacteria, and significant but weak correlations were detected between disinfectant and antibiotic resistance (against sulfamethoxazole, tetracycline and amoxicillin).The applicability of a minimum-selectable-concentration model (MSC) for the selection of resistant population was evaluated for the first time in this study. MSCs were found to be lower than minimum inhibitory concentrations (MIC) causing the enrichment of resistant populations at sub-inhibitory concentrations. Both MIC and MSC metrics should be considered when planning treatment against resistant organisms. Finally, the potential roles of dispersal and gene enrichment in a model distribution system were explored. Different pipe surfaces, especially PVC, became colonized with bacteria and enriched the abundances of resistant populations in the presence of free chlorine. Additionally, resistant bacteria were enriched more in biofilm than water. This thesis highlights how water-distribution ecosystems contribute to the emergence of resistance. The water-supply system must be considered for the control of resistant bacteria. Further, we must prevent the presence of microorganisms post-treatment as exposure to sub-inhibitory disinfectant levels causes the greatest risk.
Author: Karina Yew-Hoong Gin
Publisher: MDPI
ISBN: 3038976083
Category : Technology & Engineering
Languages : en
Pages : 188
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Book Description
This Special Issue on Antimicrobial Resistance in Environmental Waters features 11 articles on the monitoring and surveillance of antimicrobial resistance (AMR) in natural aquatic systems (i.e., reservoirs, rivers), and effluent discharge from water treatment plants to assess the effectiveness of AMR removal and resulting loads in treated waters. Some of the key elements of AMR studies presented in this Special Issue highlight the underlying drivers of AMR contamination in the environment and the evaluation of the hazard imposed on aquatic organisms in receiving environments through ecological risk assessments. As described in this Issue, screening antimicrobial peptide (AMP) libraries for biofilm disruption and antimicrobial candidates are promising avenues for the development of new treatment options to eradicate resistance.
Author: Björn H. Junker
Publisher: John Wiley & Sons
ISBN: 1118209915
Category : Computers
Languages : en
Pages : 278
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Book Description
An introduction to biological networks and methods for their analysis Analysis of Biological Networks is the first book of its kind to provide readers with a comprehensive introduction to the structural analysis of biological networks at the interface of biology and computer science. The book begins with a brief overview of biological networks and graph theory/graph algorithms and goes on to explore: global network properties, network centralities, network motifs, network clustering, Petri nets, signal transduction and gene regulation networks, protein interaction networks, metabolic networks, phylogenetic networks, ecological networks, and correlation networks. Analysis of Biological Networks is a self-contained introduction to this important research topic, assumes no expert knowledge in computer science or biology, and is accessible to professionals and students alike. Each chapter concludes with a summary of main points and with exercises for readers to test their understanding of the material presented. Additionally, an FTP site with links to author-provided data for the book is available for deeper study. This book is suitable as a resource for researchers in computer science, biology, bioinformatics, advanced biochemistry, and the life sciences, and also serves as an ideal reference text for graduate-level courses in bioinformatics and biological research.
Author: Cassandra Helt
Publisher:
ISBN:
Category :
Languages : en
Pages :
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Book Description
The ubiquitous nature of antibiotic resistance and antibiotic resistance genes (ARGs) among environmental pathogens from a variety of wastewater effluents, suggests that the aquatic environment, and specifically alternative wastewater treatment systems, may act as reservoirs for drug resistant bacteria and ARGs, thereby contributing to the widespread dissemination of antibiotic resistance. More research is necessary to contribute to our understanding of the occurrence, fate, and mobility of antibiotic resistance and ARGs among bacterial indicators of faecal contamination as well as pathogenic bacteria within Canadian wastewater treatment systems. The primary objective of this research was to determine the prevalence, fate, and potential transfer of bacterial resistance and ARGs among selected environmental pathogens exposed to alternative wastewater treatment systems, while considering the impact of treatment strategies on the expression of antibiotic resistance. A detailed analysis was initially conducted with respect to the characterization and quantification of microbial populations (including antibiotic resistant bacteria) in a variety of treatment systems and waste effluent sources. Traditional culture-based screening techniques in combination with molecular characterization (through colony or multiplex PCR), and molecular quantification using real-time quantitative PCR were utilized in order to help establish a preliminary environmental assessment of selected pathogens (Escherichia coli, Enterococcus spp., Salmonella spp.) and ARGs (tetA, blaSHV, & ampC) within a variety of wastewater treatment systems (lab-scale mesocosms, constructed wetland, constructed lagoon system, and pilot-scale biological nutrient removal (BNR) system). Overall, the level of multiple antibiotic resistance (MAR) among culturable indicator (E. coli & Enterococcus spp.) and environmental bacteria was high (reaching 100% in several instances) within different types of wastewater treatment systems and effluent sources (poultry waste effluent, municipal wastewater, aquaculture wastewater). Common antibiotic resistance profiles among E. coli isolates included simultaneous resistance to between three and five antimicrobials, whereas common MAR profiles among Enterococcus spp. isolates showed resistance to ten or more antibiotics. Real time quantitative PCR was used to determine the concentration of three bacterial pathogens; E. coli, Enterococcus faecalis, and Salmonella spp., and three ARGs; tetA, ampC, and blaSHV, within a variety of wastewater samples. Based on the results, it was concluded that high concentrations of ARGs were present in the treated effluent (104- 106 target gene copies/100 mL), regardless of system type (i.e. constructed lagoon, pilot-scale BNR, or constructed wetland), which may ultimately serve as a potential route for entry of ARGs and antibiotic resistant bacteria into the natural environment. Water is considered an important medium for transfer of resistance genes and resistant bacteria to the broader environment. Few studies have examined the transferability via conjugation of ARGs in E. coli and Salmonella spp. isolated from wastewater. Identification of three resistance determinants (tetA, strA, strB) conferring resistance to tetracycline and streptomycin was performed on selected multi-drug resistant Salmonella spp. and E. coli isolates. The potential for transfer of tetracycline and streptomycin resistance genes was demonstrated through broth conjugation experiments using multi-drug resistant Salmonella spp. and E. coli isolates as donors, and E. coli K12 as the recipient. Conjugation was successfully observed in 75% (9/12) of donor isolates, occurring in both Salmonella spp. and E. coli isolates. Six strains (50%) were capable of transferring their tetA, strA, and strB genes to the recipient strain, resulting in 58.5% (38/65) of total transconjugant strains acquiring all three resistance determinants. The results confirm the role of environmental bacteria (isolated from wastewater treatment utilities) as a reservoir of antibiotic resistance and ARGs, containing mobile genetic elements, which are capable of disseminating and transferring ARGs. As concerns about water quality and environmental contamination by human and agricultural effluents have increased, it has become increasingly more important to consider the prevalence and transferability of ARGs to opportunistic and human pathogens. As observed in this research, the ubiquitous nature of multi-drug resistant bacteria in water and wastewater effluents, the presence of diverse ARGs of human and veterinary health significance, as well as the transfer of resistance determinants through conjugative plasmids to recipient bacteria, suggests that environmental exposure through contact or consumption with contaminated water is probable. However, a lack of critical information still exists regarding the movement of resistance genes within and between microbial populations in the environment. In addition, the extent of human exposure to ARGs and antibiotic resistant bacteria is still not well understood, and future studies on human exposure to these resistant contaminants are necessary.
Author: Maulin P. Shah
Publisher: Springer Nature
ISBN: 3031446186
Category : Science
Languages : en
Pages : 129
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Book Description
This book discusses the key problems and solutions with various applicable approaches to combat antibiotic-resistant genes in industrial waste water. Several genes are selected within the chapters to illustrate the past and future roles of molecular ecophysiology and genomics in the development of wastewater microbiology as an important subdiscipline of microbial ecology. As we have very limited knowledge of composition, dynamics and stability of microbial communities, various processes in wastewater treatment have been generally considered to be "black box." In recent years, with the development of several new high throughput sequencing platforms, metagenome sequencing strategies and bioinformatics toolboxes, the analysis of the genome of complex communities has become much more accessible and means easier. The opening of the biological wastewater treatment “black box” is not the unpleasant experience it was before. The viable, but not cultural, ceases to be the inconsequential, uncharacterizable enigma that existed today. Metagenomics leads the way for more specific studies in related fields. Finally, genomic studies of wastewater treatment microbes, in addition to their biotechnological applications, are also an excellent testing ground for variety of other ecological and environmental burns questions. Wastewater treatment plants are considered hotspots for the environmental dissemination of antimicrobial-resistant determinants. Comparative genomics of antibiotic resistant genes isolated from conventional activated sludge and biological aerated filter wastewater treatment plants is discussed.
Author: National Academies of Sciences, Engineering, and Medicine
Publisher: National Academies Press
ISBN: 0309466520
Category : Medical
Languages : en
Pages : 173
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Book Description
As of 2017, the emergence and spread of antimicrobial resistance continues unabated around the world, leaving devastating health and economic outcomes in its wake. Those consequences will multiply if collaborative global action is not taken to address the spread of resistance. Major drivers of antimicrobial resistance in humans have been accelerated by inappropriate antimicrobial prescribing in health care practices; the inappropriate use of antimicrobials in livestock; and the promulgation of antibiotic resistance genes in the environment. To explore the issue of antimicrobial resistance, the Forum of Microbial Threats planned a public workshop. Participants explored issues of antimicrobial resistance through the lens of One Health, which is a collaborative approach of multiple disciplines - working locally, nationally, and globally - for strengthening systems to counter infectious diseases and related issues that threaten human, animal, and environmental health, with an end point of improving global health and achieving gains in development. They also discussed immediate and short-term actions and research needs that will have the greatest effect on reducing antimicrobial resistance, while taking into account the complexities of bridging different sectors and disciplines to address this global threat. This publication summarizes the presentations and discussions from the workshop.
