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Emerging Approaches for Typing, Detection, Characterization, and Traceback of Escherichia coli

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889451357 Year: Pages: 170 DOI: 10.3389/978-2-88945-135-7 Language: English
Publisher: Frontiers Media SA
Subject: Microbiology --- Science (General)
Added to DOAB on : 2017-07-06 13:27:36
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Pathogenic Escherichia coli strains cause a large number of diseases in humans, including diarrhea, hemorrhagic colitis, hemolytic uremic syndrome, urinary tract infections, and neonatal meningitis, while in animals they cause diseases such as calf scours and mastitis in cattle, post-weaning diarrhea and edema disease in pigs, and peritonitis and airsacculitis in chickens. The different E. coli pathotypes are characterized by the presence of specific sets of virulence-related genes. Therefore, it is not surprising that pathogenic E. coli constitutes a genetically heterogeneous family of bacteria, and they are continuing to evolve. Rapid and accurate molecular methods are critically needed to detect and trace pathogenic E. coli in food and animals. They are also needed for epidemiological investigations to enhance food safety, as well as animal and human health and to minimize the size and geographical extent of outbreaks. The serotype of E. coli strains has traditionally been determined using antisera raised against the >180 different O- (somatic) and 53 H- (flagellar) antigens. However, there are many problems associated with serotyping, including: it is labor-intensive and time consuming; cross reactivity of the antisera with different serogroups occurs; antisera are available only in specialized laboratories; and many strains are non-typeable. Molecular serotyping targeting O-group-specific genes within the E. coli O-antigen gene clusters and genes that are involved in encoding for the different flagellar types offers an improved approach for determining the E. coli O- and H-groups. Furthermore, molecular serotyping can be coupled with determination of specific sets of virulence genes carried by the strain offering the possibility to determine O-group, pathotype, and the pathogenic potential simultaneously. Sequencing of the O-antigen gene clusters of all of the known O-groups of E. coli is now complete, and the sequences have been deposited in the GenBank database. The sequence information has revealed that some E. coli serogroups have identical sequences while others have point mutations or insertion sequences and type as different serogroups in serological reactions. There are also a number of other ambiguities in serotyping that need to be resolved. Furthermore, new E. coli O-groups are being identified. Therefore, there is an essential need to resolve these issues and to revise the E. coli serotype nomenclature based on these findings. There are emerging technologies that can potentially be applied for molecular serotyping and detection and characterization of E. coli. On a related topic, the genome sequence of thousands of E. coli strains have been deposited in GenBank, and this information is revealing unique markers such as CRISPR (clustered regularly interspaced short palindromic repeats) and virulence gene markers that could be used to identify E. coli pathotypes. Whole genome sequencing now provides the opportunity to study the role of horizontal gene transfer in the evolution and emergence of pathogenic E. coli strains. Whole genome sequencing approaches are being investigated for genotyping and outbreak investigation for regulatory and public health needs; however, there is a need for establishing bioinformatics pipelines able to handle large amounts of data as we move toward the use of genetic approaches for non-culture-based detection and characterization of E. coli and for outbreak investigations.

Emerging Approaches for Typing, Detection, Characterization, and Traceback of Escherichia coli, 2nd Edition

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889454334 Year: Pages: 172 DOI: 10.3389/978-2-88945-433-4 Language: English
Publisher: Frontiers Media SA
Subject: Science (General) --- Microbiology
Added to DOAB on : 2018-11-16 17:17:57
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Pathogenic Escherichia coli strains cause a large number of diseases in humans, including diarrhea, hemorrhagic colitis, hemolytic uremic syndrome, urinary tract infections, and neonatal meningitis, while in animals they cause diseases such as calf scours and mastitis in cattle, post-weaning diarrhea and edema disease in pigs, and peritonitis and airsacculitis in chickens. The different E. coli pathotypes are characterized by the presence of specific sets of virulence-related genes. Therefore, it is not surprising that pathogenic E. coli constitutes a genetically heterogeneous family of bacteria, and they are continuing to evolve. Rapid and accurate molecular methods are critically needed to detect and trace pathogenic E. coli in food and animals. They are also needed for epidemiological investigations to enhance food safety, as well as animal and human health and to minimize the size and geographical extent of outbreaks. The serotype of E. coli strains has traditionally been determined using antisera raised against the >180 different O- (somatic) and 53 H- (flagellar) antigens. However, there are many problems associated with serotyping, including: it is labor-intensive and time consuming; cross reactivity of the antisera with different serogroups occurs; antisera are available only in specialized laboratories; and many strains are non-typeable. Molecular serotyping targeting O-group-specific genes within the E. coli O-antigen gene clusters and genes that are involved in encoding for the different flagellar types offers an improved approach for determining the E. coliO- and H-groups. Furthermore, molecular serotyping can be coupled with determination of specific sets of virulence genes carried by the strain offering the possibility to determine O-group, pathotype, and the pathogenic potential simultaneously. Sequencing of the O-antigen gene clusters of all of the known O-groups of E. coli is now complete, and the sequences have been deposited in the GenBank database. The sequence information has revealed that some E. coli serogroups have identical sequences while others have point mutations or insertion sequences and type as different serogroups in serological reactions. There are also a number of other ambiguities in serotyping that need to be resolved. Furthermore, new E. coli O-groups are being identified. Therefore, there is an essential need to resolve these issues and to revise the E. coli serotype nomenclature based on these findings. There are emerging technologies that can potentially be applied for molecular serotyping and detection and characterization of E. coli. On a related topic, the genome sequence of thousands of E. coli strains have been deposited in GenBank, and this information is revealing unique markers such as CRISPR (clustered regularly interspaced short palindromic repeats) and virulence gene markers that could be used to identify E. coli pathotypes. Whole genome sequencing now provides the opportunity to study the role of horizontal gene transfer in the evolution and emergence of pathogenic E. coli strains. Whole genome sequencing approaches are being investigated for genotyping and outbreak investigation for regulatory and public health needs; however, there is a need for establishing bioinformatics pipelines able to handle large amounts of data as we move toward the use of genetic approaches for non-culture-based detection and characterization of E. coli and for outbreak investigations.

Cyanobacteria: The Green E. coli

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889198122 Year: Pages: 114 DOI: 10.3389/978-2-88919-812-2 Language: English
Publisher: Frontiers Media SA
Subject: Biotechnology --- General and Civil Engineering
Added to DOAB on : 2016-01-19 14:05:46
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As the world struggles to reduce its dependence on fossil fuels and curb greenhouse gas emissions, industrial biotechnology is also ‘going green.’ Escherichia coli has long been used as a model Gram-negative bacterium, not only for fundamental research, but also for industrial applications. Recently, however, cyanobacteria have emerged as candidate chassis for the production of commodity fuels and chemicals, utilizing CO2 and sunlight as the main nutrient requirements. In addition to their potential for reducing greenhouse gas emissions and lowering production costs, cyanobacteria have naturally efficient pathways for the production metabolites such as carotenoids, which are of importance in the nutraceutical industry. The unique metabolic and regulatory pathways present in cyanobacteria present new challenges for metabolic engineers and synthetic biologists. Moreover, their requirement for light and the dynamic regulatory mechanisms of the diurnal cycle further complicate the development and application of cyanobacteria for industrial applications. Consequently, significant advancements in cyanobacterial engineering and strain development are necessary for the development of a ‘green E. coli’. This Research Topic will focus on cyanobacteria as organisms of emerging industrial relevance, including research focused on the development of genetic tools for cyanobacteria, the investigation of new cyanobacterial strains, the construction of novel cyanobacterial strains via genetic engineering, the application of ‘omics’ tools to advance the understanding of engineered cyanobacteria, and the development of computational models for cyanobacterial strain development.

Drinking Water Quality and Human Health

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ISBN: 9783038977261 Year: Pages: 374 DOI: 10.3390/books978-3-03897-727-8 Language: eng
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Sociology --- Social Sciences
Added to DOAB on : 2019-04-05 10:34:31
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The quality of drinking water is paramount for public health. Despite important improvements in the last decades, access to safe drinking water is not universal. The World Health Organization estimates that almost 10% of the population in the world do not have access to improved drinking water sources. Among other diseases, waterborne infections cause diarrhea, which kills nearly one million people every year, mostly children under 5 years of age. On the other hand, chemical pollution is a concern in high-income countries and an increasing problem in low- and middle-income countries. Exposure to chemicals in drinking water may lead to a range of chronic non-communicable diseases (e.g., cancer, cardiovascular disease), adverse reproductive outcomes, and effects on children’s health (e.g., neurodevelopment), among other health effects. Although drinking water quality is regulated and monitored in many countries, increasing knowledge leads to the need for reviewing standards and guidelines on a nearly permanent basis, both for regulated and newly identified contaminants. Drinking water standards are mostly based on animal toxicity data, and more robust epidemiologic studies with accurate exposure assessment are needed. The current risk assessment paradigm dealing mostly with one-by-one chemicals dismisses the potential synergisms or interactions from exposures to mixtures of contaminants, particularly at the low-exposure range. Thus, evidence is needed on exposure and health effects of mixtures of contaminants in drinking water. Finally, water stress and water quality problems are expected to increase in the coming years due to climate change and increasing water demand by population growth, and new evidence is needed to design appropriate adaptation policies.This Special Issue of International Journal of Environmental Research and Public Health (IJERPH) focuses on the current state of knowledge on the links between drinking water quality and human health.

Keywords

Vibrio pathogens --- rural water resources --- public health --- sub-Saharan Africa --- diarrhoeal disease --- HWTS implementation --- water and sanitation --- drinking water guidance --- infant exposure --- chemical risk assessment --- duration extrapolation --- acute gastroenteritis --- risk --- tap water --- time series study --- turbidity --- urban area --- water operation data --- THMs --- cancer --- effect measure modification --- drinking water --- drinking water --- exposure assessment --- sodium --- potassium --- magnesium --- calcium --- spatial variations --- Denmark --- water safety plans --- drinking water quality --- risk management --- impact assessment --- Asia-Pacific region --- diarrhea --- fever --- cough --- Nigeria --- infant health --- drinking water --- inorganic manganese --- health-based guideline --- infants --- pharmaceuticals --- human health --- environment --- drug labels --- screening method --- LTD --- uncertainty factors --- risk assessment --- risk context --- biomonitoring --- dental health --- drinking water --- fluoride --- pharmacokinetic modeling --- waterborne disease outbreak --- simulation study --- health insurance data --- space–time detection --- drinking water --- nitrate --- cancer --- adverse reproductive outcomes --- methemoglobinemia --- thyroid disease --- endogenous nitrosation --- N-nitroso compounds --- E. coli --- monitoring --- drinking water --- water safety plan --- sanitary inspection --- gravity-fed piped water scheme --- risk management --- chlorination by-product --- France --- environmental exposure --- organic matter --- tap water --- trihalomethanes --- private wells --- groundwater --- drinking water --- animal feeding operation --- fecal coliforms --- enterococci --- E. coli --- Maryland --- nitrite --- disinfection by-product --- drinking water distribution systems --- seasonality --- atrazine --- community water system --- low birth weight --- preterm birth --- small for gestational age --- water contamination --- endocrine disruptor --- drinking water --- radioactivity --- annual effective dose --- carcinogenic --- chronic kidney disease --- end-stage renal disease --- water contaminants --- zinc --- ammonia --- chemical oxygen demand --- dissolved oxygen --- arsenic

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