Search

The validity of using indicator organisms was tested to predict the presence of absence of pathogens at six wastewater reclamation facilities. A major goal of wastewater reclamation facilities is to reduce pathogen loads in order to decrease public health risks associated with exposure.

This paper examines the economic impact potential of a major innovative effort by the US Government to systematically coordinate, implement, and manage a technical infrastructure to support innovation and subsequent market penetration of advanced material technologies. Called the Materials Genome Initiative (MGI), this high-tech infrastructure consists of a range of policy instruments that can be used to leverage the efficiency of both research and development and production. To determine and rank the potential economic impacts of various MGI infrastructure targets and thereby provide policy input for portfolio management, surveys were conducted to obtain industry estimates of materials infrastructure needs. From these surveys, the economic benefits of implementing the MGI were calculated. The analysis projects potential economic benefits from an improved materials innovation infrastructure of between $123 billion and $270 billion per year. [ABSTRACT FROM AUTHOR]

The presence of all three classes of pathogens (viral, protozoan and bacterial) as well as indicator microbes at a non-point source recreational beach is assessed. The analysis of the various microbes under different targeted environmental conditions has included the evaluation of the sources of microbial contaminants and pathogens and the effectiveness of various analytical methods for microbe detection.

A TaqMan quantitative PCR (QPCR) assay is developed and optimized based on the conserved T antigen in order to quantify and detect two human polyomaviruses (HPyVs), JC virus and BK virus. The use of this quantitative assay in water quality research might help regulatory agencies in identifying sources of water pollution for improved remediation of contaminated waters and thus protecting humans from exposure to pathogens.

A method developed to concentrate and extract human polyomaviruses (HPyVs) DNA, which are used as indicators of human fecal pollution, from environmental water samples and to amplify it by nested PCR is presented. The sensitivity, specificity and correlation with other human-associated markers have indicated that the HPyV assay can be a useful predictor of human fecal pollution in environmental waters and an important component of the microbial-source-tracking toolbox.

This article describes the microbial source tracking methods, which trace fecal pollution using microbiological, genotypic, phenotypic, and chemical protocols. An overview of these methods and how they can be used to predict and identify sources of fecal pollution in the environemnt is presented. Current data indicate that there is no single approach for the identification specific sources of fecal pollution.

This paper shows that the probability of small business firms obtaining outside financing to support their research and development projects is greater given more complex commercial opportunities – defined as a greater number of different potential applications for a project’s anticipated results – for their innovations. The effects on the probability of outside finance found for other factors are consistent with the earlier findings in the literature about innovative entrepreneurial firms. [ABSTRACT FROM AUTHOR]

This paper examines how strategic alliances to create and use standards affect economic growth and development. The explanation of the link from standards to economic growth and development is through the effects of standards on the incentives to perform industrial research and development (R&D). We examine product standards, metrology traceable to national and international standards, and regulatory standards to address negative externalities. The paper develops a theoretical explanation for the link from standards to growth, survey/interview-guides to gather information from industrial R&D experts about the explanation, and case-study evidence about the explanation. We discuss the standard-setting process and explain that it entails strategic alliances among firms and with government involvement. Case studies of R&D projects in firms and in a national laboratory support the belief that standards implemented via strategic alliances leverage economic growth and development. [ABSTRACT FROM PUBLISHER]

Studies evaluating the relationship between microbes and human health at non-point source beaches are necessary for establishing criteria which would protect public health while minimizing economic burdens. The objective of this study was to evaluate water quality and daily cumulative health effects (gastrointestinal, skin, and respiratory illnesses) for bathers at a non-point source subtropical marine recreational beach in order to better understand the inter-relationships between these factors and hence improve monitoring and pollution prevention techniques. Daily composite samples were collected, during the Oceans and Human Health Beach Exposure Assessment and Characterization Health Epidemiologic Study conducted in Miami (Florida, USA)at a non-point source beach, and analyzed for several pathogens, microbial source tracking markers, indicator microbes, and environmental parameters. Analysis demonstrated that rainfall and tide were more influential, when compared to other environmental factors and source tracking markers, in determining the presence of both indicator microbes and pathogens. Antecedent rainfall and F+ coliphage detection in water should be further assessed to confirm their possible association with skin and gastrointestinal (GI) illness outcomes, respectively. The results of this research illustrate the potential complexity of beach systems characterized by non-point sources, and how more novel and comprehensive approaches are needed to assess beach water quality for the purpose of protecting bather health. [ABSTRACT FROM AUTHOR]

In the United States, total maximum daily load standards for bodies of water that do not meet bacterial water quality standards are set by each state. The presence of human polyomaviruses (HPyVs) can be used as an indicator of human-associated sewage pollution in these waters. We have developed and optimized a TaqMan quantitative PCR (QPCR) assay based on the conserved T antigen to both quantity and simultaneously detect two HPyVs; JC virus and BK virus. The QPCR assay was able to consistently quantify ≥10 gene copies per reaction and is linear over 5 orders of magnitude. HPyVs were consistently detected in human waste samples (57 of 64) and environmental waters with known human fecal contamination (5 of 5) and were not amplified in DNA extracted from 127 animal waste samples from 14 species. HPyV concentrations in sewage decreased 81.2 and 84.2% over 28 days incubation at 25 and 35°C, respectively. HPyVs results were compared to Escherichia coli, fecal coliform, and enterococci concentrations and the presence of three other human-associated microbes: Bacteroidetes, Methanobrevibacter smithii,and adenovirus. HPyVs were the most frequently detected of these in human and contaminated environmental samples and were more human specific than the Bacteroidetes (HF183) or M. smithii. HPyVs and M. smithii more closely mimicked the persistence of adenovirus in sewage than the other microbes. The use of this rapid and quantitative assay in water quality research could help regulatory agencies to identify sources of water pollution for improved remediation of contaminated waters and ultimately protect humans from exposure to pathogens. [ABSTRACT FROM AUTHOR]

Several genotypic and phenotypic microbial source tracking (MST) methods have been proposed and utilized to differentiate groups of microorganisms, usually indicator organisms, for the purpose of tracking sources of fecal pollution. Targeting of host-specific microorganisms is one of the approaches currently being tested. These methods are useful as they circumvent the need to isolate individual microorganisms and do not require the establishment of reference databases. Several studies have demonstrated that the presence and distribution of Enterococcus spp. in feces seems to be influenced by the host species. Here, we present a method for detection of genetic sequences in culturable enterococci capable of identifying human sources of fecal pollution in the environment. The human fecal pollution marker designed in this study targets a putative virulence factor, the enterococcal surface protein (esp), in Enterococcus faecium. This gene was detected in 97% of sewage and septic samples but was not detected in any livestock waste lagoons or in bird or animal fecal samples. Epidemiological studies in recreational and groundwaters have shown enterococci to be useful indicators of public health risk for gastroenteritis. By identifying the presence of human fecal pollution, and therefore the possible presence of human enteric pathogens, this marker allows for further resolution of the source of this risk. [ABSTRACT FROM AUTHOR]

Describes the geographical variation in ribotype profiles of Escherichia coli isolates from humans and livestocks in Florida. Impact of fecal pollution on human health; Sources of fecal contamination; Statistical analysis of ribotype profiles.

The efficacy levels of different physical and chemical washing treatments in the reduction of viral and bacterial pathogens from inoculated strawberries were evaluated. Escherichia coli O157:H7, Salmonella Montevideo, poliovims 1, and the bacteriophages PRD1, φX174, and MS2 were used as model and surrogate organisms. Chemicals readily available to producers and/or consumers were evaluated as antimicrobial additives for the production of washes. The gentle agitation of contaminated strawberries in water for 2 min led to reductions in microbial populations ranging from 41 to 79% and from 62 to 90% at water temperatures of 22 and 43°C, respectively. Significant reductions (>98%) in numbers of bacteria and viruses were obtained with sodium hypochlorite (50 to 300 ppm of free chlorine), Oxine or Carnebon (200 ppm of product generating "stabilized chlorine dioxide"), Tsunami (100 ppm of peroxyacetic acid), and Alcide (100 or 200 ppm of acidified sodium chlorite) washes. Overall, 200 ppm of acidified sodium chlorite produced the greatest reductions of microorganisms. Hydrogen peroxide (0.5%) was slightly less effective than free chlorine in a strawberry wash and caused slight fruit discoloration. Cetylpyridinium chloride (0.1%) was effective in the reduction of bacterial species, while trisodium phosphate (1%) was effective against viruses. The consumer-oriented produce wash Fit was very effective (>99%) in reducing the numbers of bacteria but not in reducing the numbers of viruses. Another wash, Healthy Harvest, was significantly less effective than Fit in reducing bacterial pathogens but more effective for viruses. The performance of automatic dishwashing detergent was similar to that of Healthy Harvest and significantly better than that of liquid dishwashing detergent. Solutions containing table salt (2% NaCl) or vinegar (10%) reduced the numbers of bacteria by about 90%, whereas only the vinegar wash reduced the numbers of viruses significantly (ca. 95%). [ABSTRACT FROM AUTHOR]

Investigates the direct and indirect effects of mono-, di-, and trivalent salts on the adsorption of several viruses to microporous filters at different pH values. Enhanced adsorption of viruses due to indirect effects; Reduction in the pH of the water due to the salts.

In this article the authors discuss aspects of the report "Environmental Occurrence of the Enterococcal Surface Protein (esp) Gene is an Unreliable Indicator of Human Fecal Contamination," by researcher Byappanahalli and colleagues. The authors are critical of the team's use and utility of the Enterococcas faecalis esp gene to track microbial sources of fecal contamination, such as polymerase chain reaction (PCR) methods, and discuss why it is a misrepresentation of fecal indicators.

Abstract: Criteria for sub-typing of microbial organisms by DNA sequencing proposed by Olive and Bean were applied to several genes in Escherichia coli to identify targets for the development of microbial source tracking assays. Based on the aforementioned criteria, the icd (isocitrate dehydrogenase), and putP (proline permease) genes were excluded as potential targets due to their high rates of horizontal gene transfer; the rrs (16S rRNA) gene was excluded as a target due to the presence of multiple gene copies, with different sequences in a single genome. Based on the above criteria, the mdh (malate dehydrogenase) gene was selected as a target for development of a microbial source tracking assay. The mdh assay was optimized to analyze a 150bp fragment corresponding to residues G191 to R240 (helices H10 and H11) of the Mdh catalytic domain. 295 fecal isolates (52 horse, 50 deer, 72 dog, 52 seagull and 69 human isolates) were sequenced and analyzed. Target DNA sequences for isolates from horse, dog plus deer, and seagull formed identifiable groupings. Sequences from human isolates, aside from a low level (ca. 15%) human specific sequence, did not group; nevertheless, other hosts could be distinguished from human. Positive and negative predictive values for two- and three-way host comparisons ranged from 60% to 90% depending on the focus host. False positive rates were below 10%. Multiple E. coli isolates from individual fecal samples exhibited high levels of sequence homogeneity, i.e. typically only one to two mdh sequences were observed per up to five E. coli isolates from a single fecal sample. Among all isolates sequenced from fecal samples from each host, sequence homogeneity decreased in the following order: horse>dog>deer>human and gull. For in-library isolates, blind analysis of fecal isolates (n =12) from four hosts known to contain host specific target sequences was 100% accurate and 100% reproducible for both DNA sequence and host identification. For blind analysis of non-library isolates, 18/19 isolates (94.7%) matched one or more library sequences for the corresponding host. Ten of eleven geographical outlier fecal isolates from Florida had mdh sequences that were identical to in-library sequences for the corresponding host from California. The mdh assay was successfully applied to environmental isolates from an underground telephone vault in California, with 4 of 5 isolates matching sequences in the mdh library. 146 sequences of the 645bp mdh fragment from five host sources were translated into protein sequence and aligned. Seven unique Mdh protein sequences, which contained eight polymorphic sites, were identified. Six of the polymorphic sites were in the NAD+ binding domain and two were in the catalytic domain. All of the polymorphic sites were located in surface exposed regions of the protein. None of the non-silent mutations of the Mdh protein were in the 150bp mdh target. The advantages and disadvantages of the assay compared to established source tracking methods are discussed. [Copyright &y& Elsevier]