Disinfection of hepatitis A virus and MS-2 coliphage in water by ultraviolet irradiation: comparison of UV-susceptibilty

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Wiedenmann, A; Fischer, B; Straub, U; Wang, C -H; Flehmig, B [Tuebingen Univ. (Germany). Hygiene-Inst.; Schoenen, D [Bonn Univ. (Germany). Hygiene-Inst.

1993-01-01

Ultraviolet irradiation is gaining importance as a disinfection procedure for drinking water and in waste water treatment. Since water is one of the main transmission routes of hepatitis A virus the susceptibility of Hepatitis A Virus (HAV) to UV rays is of special interest. MS-2 coliphage resembles HAV in size and structure, is easy to handle, and might therefore serve as indicator organism for the assessment of water quality and for evaluating the quality of water treatment processes. Hepatitis A virus and MS-2 coliphage were suspended in 0.9% sodium chloride solution and were irradiated in a 20-ml quartz cuvette at 254 nm. For a reduction rate of four log units a three times higher UV dose was required with MS-2 than with HAV. (author).

Disinfection of hepatitis A virus and MS-2 coliphage in water by ultraviolet irradiation: comparison of UV-susceptibilty

International Nuclear Information System (INIS)

Wiedenmann, A.; Fischer, B.; Straub, U.; Wang, C.-H.; Flehmig, B.; Schoenen, D.

1993-01-01

Ultraviolet irradiation is gaining importance as a disinfection procedure for drinking water and in waste water treatment. Since water is one of the main transmission routes of hepatitis A virus the susceptibility of Hepatitis A Virus (HAV) to UV rays is of special interest. MS-2 coliphage resembles HAV in size and structure, is easy to handle, and might therefore serve as indicator organism for the assessment of water quality and for evaluating the quality of water treatment processes. Hepatitis A virus and MS-2 coliphage were suspended in 0.9% sodium chloride solution and were irradiated in a 20-ml quartz cuvette at 254 nm. For a reduction rate of four log units a three times higher UV dose was required with MS-2 than with HAV. (author)

Coliphage 186 replication is delayed when the host cell is UV irradiated before infection

International Nuclear Information System (INIS)

Hooper, I.; Woods, W.H.; Egan, B.

1981-01-01

In contrast to results with injections by lambda and P2, the latent period for infection by coliphage 186 is extended when the host cell is UV irradiated before infection. We find that 186 replication is significantly delayed in such a cell, even though the phage itself has not been irradiated. In contrast, replication of the closely related phage P2 under the same conditions is not affected

Organic Wastewater Compounds, Pharmaceuticals, andColiphage in Ground Water Receiving Discharge from OnsiteWastewater Treatment Systems near La Pine, Oregon:Occurrence and Implications for Transport

Science.gov (United States)

Hinkle, Stephen J.; Weick, Rodney J.; Johnson, Jill M.; Cahill, Jeffery D.; Smith, Steven G.; Rich, Barbara J.

2005-01-01

The occurrence of organic wastewater compounds (components of 'personal care products' and other common household chemicals), pharmaceuticals (human prescription and nonprescription medical drugs), and coliphage (viruses that infect coliform bacteria, and found in high concentrations in municipal wastewater) in onsite wastewater (septic tank effluent) and in a shallow, unconfined, sandy aquifer that serves as the primary source of drinking water for most residents near La Pine, Oregon, was documented. Samples from two types of observation networks provided basic occurrence data for onsite wastewater and downgradient ground water. One observation network was a group of 28 traditional and innovative (advanced treatment) onsite wastewater treatment systems and associated downgradient drainfield monitoring wells, referred to as the 'innovative systems network'. The drainfield monitoring wells were located adjacent to or under onsite wastewater treatment system drainfield lines. Another observation network, termed the 'transect network', consisted of 31 wells distributed among three transects of temporary, stainless-steel-screened, direct-push monitoring wells installed along three plumes of onsite wastewater. The transect network, by virtue of its design, also provided a basis for increased understanding of the transport of analytes in natural systems. Coliphage were frequently detected in onsite wastewater. Coliphage concentrations in onsite wastewater were highly variable, ranging from less than 1 to 3,000,000 plaque forming units per 100 milliliters. Coliphage were occasionally detected (eight occurrences) at low concentrations in samples from wells located downgradient from onsite wastewater treatment system drainfield lines. However, coliphage concentrations were below method detection limits in replicate or repeat samples collected from the eight sites. The consistent absence of coliphage detections in the replicate or repeat samples is interpreted to indicate

Disinfection efficiency of peracetic acid (PAA): inactivation of coliphages and bacterial indicators in a municipal wastewater plant.

Science.gov (United States)

Zanetti, F; De Luca, G; Sacchetti, R; Stampi, S

2007-11-01

The aim of the study was to assess the efficiency of low doses of peracetic acid against viral and bacterial indicators in wastewater and to evaluate if the treatment allows regulatory requirements to be satisfied. A total of 31 samplings were carried out, each involving the collection of secondary effluent and of effluent disinfected with 1.2 or 1.5 mg l(-1) of peracetic acid (contact time 20 minutes). In each sample were measured: somatic coliphages, F-specific RNA bacteriophages, Escherichia coli, total and faecal coliforms, enterococci. Peracetic acid disinfection showed significant differences between the reductions of the microorganisms tested: E. coli showed the highest reduction (1.78 and 2.43 Log respectively with 1.2 and 1.5 mg l(-1) of peracetic acid) and phages the lowest (ranging between 0.52 and 0.60 Log). Only a concentration of 1.5 mg l(-1) of peracetic acid would enable the effluent to be discharged into surface waters in compliance with Italian regulations. The variability of microbial resistance against the peracetic acid disinfection treatment, underlines the importance of assessing disinfection efficiency by using more than one indicator microorganism. The detection of E. coli could be usefully accompanied by tests for more resistant microorganisms such as enterococci or coliphages. In conclusion, peracetic acid can be used for the disinfection of effluents even at low doses, with the advantage of reducing costs and preventing the formation of significant amounts of genotoxic by-products.

Effect of Temperature on the Survival of F-Specific RNA Coliphage, Feline Calicivirus, and Escherichia coli in Chlorinated Water

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Sagar M. Goyal

2005-12-01

Full Text Available We compared the survival of F-specific RNA coliphage MS2, feline calicivirus, and E. coli in normal tap water and in tap water treated to an initial concentration of 50 ppm free chlorine and held at 4°C, 25°C, or 37°C for up to 28 days. Our aim was to determine which of these two organisms (coliphage or E. coli was better at indicating norovirus survival under the conditions of the experiment. There was a relatively rapid decline of FCV and E. coli in 50 ppm chlorine treated water and both organisms were undetectable within one day irrespective of the temperature. In contrast, FRNA phage survived for 7 to 14 days in 50 ppm chlorine treated water at all temperatures. All organisms survived for 28 days in tap water at 4°C, but FCV was undetectable on day 21 and day 7 at 25°C and 37°C, respectively. Greater survival of FRNA phage compared to E. coli in 50 ppm chlorine treated water suggests that these organisms should be further investigated as indicators of norovirus in depurated shellfish, sanitized produce, and treated wastewater which are all subject to high-level chlorine treatment.

Elimination of fecal coliforms and F-specific RNA coliphage from oysters (Crassostrea virginica) relaid in floating containers.

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Kator, H; Rhodes, M

2001-06-01

Declining oyster (Crassostrea virginica) production in the Chesapeake Bay has stimulated aquaculture based on floats for off-bottom culture. While advantages of off-bottom culture are significant, the increased use of floating containers raises public health and microbiological concerns, because oysters in floats may be more susceptible to fecal contamination from storm runoff compared to those cultured on-bottom. We conducted four commercial-scale studies with market-size oysters naturally contaminated with fecal coliforms (FC) and a candidate viral indicator, F-specific RNA (FRNA) coliphage. To facilitate sampling and to test for location effects, 12 replicate subsamples, each consisting of 15 to 20 randomly selected oysters in plastic mesh bags, were placed at four characteristic locations within a 0.6- by 3.0-m "Taylor" float, and the remaining oysters were added to a depth not exceeding 15.2 cm. The float containing approximately 3,000 oysters was relaid in the York River, Virginia, for 14 days. During relay, increases in shellfish FC densities followed rain events such that final mean levels exceeded initial levels or did not meet an arbitrary product end point of 50 FC/100 ml. FRNA coliphage densities decreased to undetectable levels within 14 days (16 to 28 degrees C) in all but the last experiment, when temperatures fell between 12 and 16 degrees C. Friedman (nonparametric analysis of variance) tests performed on FC/Escherichia coli and FRNA densities indicated no differences in counts as a function of location within the float. The public health consequences of these observations are discussed, and future research and educational needs are identified.

Bacterial indicator occurrence and the use of an F+ specific RNA coliphage assay to identify fecal sources in Homosassa Springs, Florida

Science.gov (United States)

Griffin, Dale W.; Stokes, Rodger; Rose, J.B.; Paul, J.H.

2000-01-01

A microbiological water quality study of Homosassa Springs State Wildlife Park (HSSWP) and surrounding areas was undertaken. Samples were collected in November of 1997 (seven sites) and again in November of 1998 (nine sites). Fecal bacterial concentrations (total and fecal coliforms, Clostridium perfringens, and enterococci) were measured as relative indicators of fecal contamination. F+-specific coliphage genotyping was performed to determine the source of fecal contamination at the study sites. Bacterial levels were considerably higher at most sites in the 1997 sampling compared to the 1998 sampling, probably because of the greater rainfall that year. In November of 1997, 2 of the 7 sites were in violation of all indicator standards and guidance levels. In November of 1998, 1 of 9 sites was in violation of all indicator standard and guidance levels. The highest concentrations of all fecal indicators were found at a station downstream of the animal holding pens in HSSWP. The lowest levels of indicators were found at the Homosassa Main Spring vent. Levels of fecal indicators downstream of HSSWP (near the point of confluence with the river) were equivalent to those found in the Southeastern Fork and areas upstream of the park influences. F+ specific RNA coliphage analysis indicated that fecal contamination at all sites that tested positive was from animal sources (mammals and birds). These results suggest that animal (indigenous and those in HSSWP) and not human sources influenced microbial water quality in the area of Homosassa River covered by this study.

In vitro evolution and affinity-maturation with Coliphage qβ display.

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Claudia Skamel

Full Text Available The Escherichia coli bacteriophage, Qβ (Coliphage Qβ, offers a favorable alternative to M13 for in vitro evolution of displayed peptides and proteins due to high mutagenesis rates in Qβ RNA replication that better simulate the affinity maturation processes of the immune response. We describe a benchtop in vitro evolution system using Qβ display of the VP1 G-H loop peptide of foot-and-mouth disease virus (FMDV. DNA encoding the G-H loop was fused to the A1 minor coat protein of Qβ resulting in a replication-competent hybrid phage that efficiently displayed the FMDV peptide. The surface-localized FMDV VP1 G-H loop cross-reacted with the anti-FMDV monoclonal antibody (mAb SD6 and was found to decorate the corners of the Qβ icosahedral shell by electron microscopy. Evolution of Qβ-displayed peptides, starting from fully degenerate coding sequences corresponding to the immunodominant region of VP1, allowed rapid in vitro affinity maturation to SD6 mAb. Qβ selected under evolutionary pressure revealed a non-canonical, but essential epitope for mAb SD6 recognition consisting of an Arg-Gly tandem pair. Finally, the selected hybrid phages induced polyclonal antibodies in guinea pigs with good affinity to both FMDV and hybrid Qβ-G-H loop, validating the requirement of the tandem pair epitope. Qβ-display emerges as a novel framework for rapid in vitro evolution with affinity-maturation to molecular targets.

Molecular characterization of bacteriophages for microbial source tracking in Korea.

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Lee, Jung Eun; Lim, Mi Young; Kim, Sei Yoon; Lee, Sunghee; Lee, Heetae; Oh, Hyun-Myung; Hur, Hor-Gil; Ko, Gwangpyo

2009-11-01

We investigated coliphages from various fecal sources, including humans and animals, for microbial source tracking in South Korea. Both somatic and F+-specific coliphages were isolated from 43 fecal samples from farms, wild animal habitats, and human wastewater plants. Somatic coliphages were more prevalent and abundant than F+ coliphages in all of the tested fecal samples. We further characterized 311 F+ coliphage isolates using RNase sensitivity assays, PCR and reverse transcription-PCR, and nucleic acid sequencing. Phylogenetic analyses were performed based on the partial nucleic acid sequences of 311 F+ coliphages from various sources. F+ RNA coliphages were most prevalent among geese (95%) and were least prevalent in cows (5%). Among the genogroups of F+ RNA coliphages, most F+ coliphages isolated from animal fecal sources belonged to either group I or group IV, and most from human wastewater sources were in group II or III. Some of the group I coliphages were present in both human and animal source samples. F+ RNA coliphages isolated from various sources were divided into two main clusters. All F+ RNA coliphages isolated from human wastewater were grouped with Qbeta-like phages, while phages isolated from most animal sources were grouped with MS2-like phages. UniFrac significance statistical analyses revealed significant differences between human and animal bacteriophages. In the principal coordinate analysis (PCoA), F+ RNA coliphages isolated from human waste were distinctively separate from those isolated from other animal sources. However, F+ DNA coliphages were not significantly different or separate in the PCoA. These results demonstrate that proper analysis of F+ RNA coliphages can effectively distinguish fecal sources.

Implementación de dos métodos de recuento en placa para la detección de colifagos somáticos, aportes a las metodologías estándar Implementation of two plate count methods for detection of somatic coliphages and contributions to the standard methodologies

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Melissa Solano Barquero

2013-01-01

Full Text Available Los métodos de recuento en placa capa doble y capa simple de agar, para la cuantificación de colifagos so-máticos en aguas, fueron implementados utilizando como base metodologías estándar. Diferentes variables fueron ensayadas, lo cual permitió la precisión en algunos pasos no incluidos en metodologías estándares. De los hallazgos de mayor importancia, se exponen las consecuencias de utilizar un cultivo de Escherichia coliexcesivamente concentrado y se describe la obtención de un cultivo en fase logarítmica en solo 4 horas de incubación, ajustando la concentración a una densidad óptica de 0,3 a 600nm (3,1 x 10 8 UFC/ mL, o a un McFarland 1 (3,0 x108 UFC/ mL. Se determinó que los controles de colifagos deben ser almacenados a -70 °C para reducir su degradación y que se deben evitar cantidades superiores a 20 mL de mezcla de reacción por plato de Petri, para reducir las burbujas que pueden interferir con la lectura de unidades formadoras de placas (UFP. Se demostró que los colifagos de las muestras de agua pueden almacenarse 48 horas a 4 °C sin que sufran degradación y que en las muestras con altas concentraciones de colifagos no se observa UFP porque se da una lisis confluente de la capa bacteriana. No se encontraron diferencias significativas en la recuperación de colifagos al utilizar un método u otro, pero dichos métodos deben ser evaluados por medio de controles, antes de aplicarlos directamente en el análisis de muestras de agua.Two plate count methods, double layer and single layer of agar for quantification of somatic coliphages in water, were implemented using standard methodologies. Several variables were tested and provided valuable information that was not included in standard methodologies. The most important findings are described, such as the effect of using an excessively concentrated culture of E. coliand production of a log phase culture in only 4 hours of incubation, adjusting the concentration to an

Detection of somatic coliphages as indicators of faecal contamination in estuarine waters Detección de colifagos somáticos como indicadores de contaminación fecal en aguas estuarinas

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S. S. Brezina

2008-03-01

Full Text Available The appearance of enteric disease outbreaks associated with the use of waters considered bacteriologically suitable, calls for the search of new and more precise indicators. Samples of estuarine water were collected in order to quantify E. coli and E. coli ATCC 13706 somatic coliphages and to compare the usefulness of the latter to detect faecal contamination when the concentration of traditional indicators is not quantifiable. Statistical analyses suggested the division of sampling sites into two groups: group I and group II, according to the minor or major level of faecal pollution respectively registered. In group II a high correlation between the coliphages and E. coli (r: 0.73 pLa aparición de brotes de enfermedades víricas entéricas asociadas al uso de aguas bacteriológicamente aptas impone la búsqueda de nuevos y más precisos indicadores de contaminación. Se recolectaron muestras de agua estuarina, donde se cuantificaron simultáneamente la bacteria E. coli y los colifagos somáticos de E. coli ATCC 13706, a fin de evaluar la utilidad de estos últimos para detectar contaminación fecal cuando la concentración de los indicadores tradicionales no es cuantificable. Los resultados estadísticos sugirieron la división de las estaciones de muestreo en dos grupos, I y II, de acuerdo con el menor o mayor nivel de contaminación fecal registrado, respectivamente. En el grupo II se detectó una alta correlación entre los recuentos de colifagos y de E. coli (r: 0,73 p<0,01. Asimismo, en este grupo la abundancia de E. coli siempre superó a la de colifagos. En el grupo I la correlación fue estadísticamente significativa (r: 0,55 p < 0,05, pero de mediana magnitud, los recuentos de colifagos superaron a los de E. coli, y éstos fueron detectados aun en ausencia de la bacteria. En conclusión, los colifagos somáticos de E. coli ATCC 13706 serían una herramienta accesoria en el diagnóstico del nivel de contaminación fecal de aguas

Reduction of bacteria and somatic coliphages in constructed wetlands for the treatment of combined sewer overflow (retention soil filters).

Science.gov (United States)

Ruppelt, Jan P; Tondera, Katharina; Schreiber, Christiane; Kistemann, Thomas; Pinnekamp, Johannes

2018-05-01

Combined sewer overflows (CSOs) introduce numerous pathogens from fecal contamination, such as bacteria and viruses, into surface waters, thus endangering human health. In Germany, retention soil filters (RSFs) treat CSOs at sensitive discharge points and can contribute to reducing these hygienically relevant microorganisms. In this study, we evaluated the extent of how dry period, series connection and filter layer thickness influence the reduction efficiency of RSFs for Escherichia coli (E. coli), intestinal enterococci (I. E.) and somatic coliphages. To accomplish this, we had four pilot scale RSFs built on a test field at the wastewater treatment plant Aachen-Soers. While two filters were replicates, the other two filters were installed in a series connection. Moreover, one filter had a thinner filtration layer than the other three. Between April 2015 and December 2016, the RSFs were loaded in 37 trials with pre-conditioned CSO after dry periods ranging from 4 to 40 days. During 17 trials, samples for microbial analysis were taken and analyzed. The series connection of two filters showed that the removal increases when two systems with a filter layer of the same height are operated in series. Since the microorganisms are exposed twice to the environmental conditions on the filter surface and in the upper filter layers, there is a greater chance for abiotic adsorption increase. The same effect could be shown when filters with different depths were compared: the removal efficiency increases as filter thickness increases. This study provides new evidence that regardless of seasonal effects and dry period, RSFs can improve hygienic situation significantly. Copyright © 2018 Elsevier GmbH. All rights reserved.

Uso de colifagos somáticos como indicadores de contaminación fecal en playas de “la Costa Verde”, Lima–Perú

OpenAIRE

Cadillo Quiroz, Hinsby; León Quispe, Jorge

2014-01-01

This study was undertaken in order to assess the use of somatic coliphages as faecal pollution indicators in recreational seawater. In 140 samples from 5 beaches at the “Costa Verde” circuit, Lima, somatic coliphages were enumerated and correlated with conventional faecal pollution indicators (Faecal coliforms, E. coli and enterococci). After sample treatment with the “Sample Filtration” modified technique, somatic coliphages were assayed by the “Single-Agar-Layer” method using the strain E....

Meta-Analysis of the Reduction of Norovirus and Male-Specific Coliphage Concentrations in Wastewater Treatment Plants.

Science.gov (United States)

Pouillot, Régis; Van Doren, Jane M; Woods, Jacquelina; Plante, Daniel; Smith, Mark; Goblick, Gregory; Roberts, Christopher; Locas, Annie; Hajen, Walter; Stobo, Jeffrey; White, John; Holtzman, Jennifer; Buenaventura, Enrico; Burkhardt, William; Catford, Angela; Edwards, Robyn; DePaola, Angelo; Calci, Kevin R

2015-07-01

Human norovirus (NoV) is the leading cause of foodborne illness in the United States and Canada. Wastewater treatment plant (WWTP) effluents impacting bivalve mollusk-growing areas are potential sources of NoV contamination. We have developed a meta-analysis that evaluates WWTP influent concentrations and log10 reductions of NoV genotype I (NoV GI; in numbers of genome copies per liter [gc/liter]), NoV genotype II (NoV GII; in gc/liter), and male-specific coliphage (MSC; in number of PFU per liter), a proposed viral surrogate for NoV. The meta-analysis included relevant data (2,943 measurements) reported in the scientific literature through September 2013 and previously unpublished surveillance data from the United States and Canada. Model results indicated that the mean WWTP influent concentration of NoV GII (3.9 log10 gc/liter; 95% credible interval [CI], 3.5, 4.3 log10 gc/liter) is larger than the value for NoV GI (1.5 log10 gc/liter; 95% CI, 0.4, 2.4 log10 gc/liter), with large variations occurring from one WWTP to another. For WWTPs with mechanical systems and chlorine disinfection, mean log10 reductions were -2.4 log10 gc/liter (95% CI, -3.9, -1.1 log10 gc/liter) for NoV GI, -2.7 log10 gc/liter (95% CI, -3.6, -1.9 log10 gc/liter) for NoV GII, and -2.9 log10 PFU per liter (95% CI, -3.4, -2.4 log10 PFU per liter) for MSCs. Comparable values for WWTPs with lagoon systems and chlorine disinfection were -1.4 log10 gc/liter (95% CI, -3.3, 0.5 log10 gc/liter) for NoV GI, -1.7 log10 gc/liter (95% CI, -3.1, -0.3 log10 gc/liter) for NoV GII, and -3.6 log10 PFU per liter (95% CI, -4.8, -2.4 PFU per liter) for MSCs. Within WWTPs, correlations exist between mean NoV GI and NoV GII influent concentrations and between the mean log10 reduction in NoV GII and the mean log10 reduction in MSCs. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Efficiency of peracetic acid in inactivating bacteria, viruses, and spores in water determined with ATP bioluminescence, quantitative PCR, and culture-based methods.

Science.gov (United States)

Park, Eunyoung; Lee, Cheonghoon; Bisesi, Michael; Lee, Jiyoung

2014-03-01

The disinfection efficiency of peracetic acid (PAA) was investigated on three microbial types using three different methods (filtration-based ATP (adenosine-triphosphate) bioluminescence, quantitative polymerase chain reaction (qPCR), culture-based method). Fecal indicator bacteria (Enterococcus faecium), virus indicator (male-specific (F(+)) coliphages (coliphages)), and protozoa disinfection surrogate (Bacillus subtilis spores (spores)) were tested. The mode of action for spore disinfection was visualized using scanning electron microscopy. The results indicated that PAA concentrations of 5 ppm (contact time: 5 min), 50 ppm (10 min), and 3,000 ppm (5 min) were needed to achieve 3-log reduction of E. faecium, coliphages, and spores, respectively. Scanning electron microscopy observation showed that PAA targets the external layers of spores. The lower reduction rates of tested microbes measured with qPCR suggest that qPCR may overestimate the surviving microbes. Collectively, PAA showed broad disinfection efficiency (susceptibility: E. faecium > coliphages > spores). For E. faecium and spores, ATP bioluminescence was substantially faster (∼5 min) than culture-based method (>24 h) and qPCR (2-3 h). This study suggests PAA as an effective alternative to inactivate broad types of microbial contaminants in water. Together with the use of rapid detection methods, this approach can be useful for urgent situations when timely response is needed for ensuring water quality.

Complete Genome Sequence of Escherichia coli Strain WG5

DEFF Research Database (Denmark)

Imamovic, Lejla; Misiakou, Maria-Anna; van der Helm, Eric

2018-01-01

Escherichia coli strain WG5 is a widely used host for phage detection, including somatic coliphages employed as standard ISO method 10705-1 (2000). Here, we present the complete genome sequence of a commercial E. coli WG5 strain.......Escherichia coli strain WG5 is a widely used host for phage detection, including somatic coliphages employed as standard ISO method 10705-1 (2000). Here, we present the complete genome sequence of a commercial E. coli WG5 strain....

PERFORMANCE OF A SURFACE FLOW CONSTRUCTED WETLAND SYSTEM USED TO TREAT SECONDARY EFFLUENT AND FILTER BACKWASH WATER

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Juan Antonio Vidales-Contreras

2011-05-01

The performance of a surface flow wetland system used to treat activated sludge effluent and filter backwash water from a tertiary treatment facility was evaluated. Samples were collected before and after vegetation removal from the system which consists of two densely vegetated settling basins (0.35 ha, an artificial stream, and a 3-ha surface flow wetland. Bulrush (Scripus spp. and cattail (Typha domingensis were the dominant plant species. The average inflow of chlorinated secondary effluent during the first two months of the actual study was 1.9  m3 min-1 while the inflow for backwash water treatment ranged from 0.21 to 0.42 m3 min-1. The system was able to reduce TSS and BOD5 to tertiary effluent standards; however, monitoring of chloride concentrations revealed that wetland evapotranspiration is probably enriching pollutant concentrations in the wetland outflow. Coliphage removal from the filter backwash was 97 and 35% during 1999 and 2000, respectively. However, when secondary effluent entered the system, coliphage removal averaged 65%. After vegetation removal, pH and coliphage density increased significantly (p

Use of reflectors to enhance the synergistic effects of solar heating and solar wavelengths to disinfect drinking water sources.

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Rijal, G K; Fujioka, R S

2003-01-01

Aluminum reflectors were added to solar units designed to inactivate faecal microorganisms (faecal coliform, E. coli, enterococci, FRNA coliphage, C. perfringens) in stream water and diluted sewage by the two mechanisms (solar heat, solar UV) known to inactivate microorganisms. During sunny conditions, solar units with and without reflectors inactivated E. coli to water standards. Solar units with reflectors disinfected the water sooner by increasing the water temperature by 8-10 degrees C to 64-75 degrees C. However, FRNA coliphages were still detected in these samples, indicating that this treatment may not inactivate pathogenic human enteric viruses. During cloudy conditions, reflectors only increased the water temperature by 3-4 degrees C to a maximum of 43-49 degrees C and E. coli was not completely inactivated. Under sunny and cloudy conditions, the UV wavelengths of sunlight worked synergistically with increasing water temperatures and were able to disinfect microorganisms at temperatures (45-56 degrees C), which were not effective in inactivating microorganisms. Relative resistance to the solar disinfecting effects were C. perfringens > FRNA coliphages > enterococci > E. coli > faecal coliform.

Bacteriophage Technique for Assessing Viral Removal in Constructed Wetland and Detention Pond Systems

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Z Yousefi, CM Davies, HJ Bavor

2004-10-01

Full Text Available Constructed wetland and detention pond as a treatment system was applied for stormwater management in two adjacent areas in western Sydney. F-specific RNA and somatic coliphages were used as a model for assessing two systems for removal of viral pollution, fate, behavior and survival of viruses in the sediment. Water samples were collected weekly in sterile containers and sediment samples were collected three times using a box dredge sampler via a boat at the inlet, middle and outlet areas of the systems. F-specific RNA coliphages were enumerated using the double layer plaque assay (ISO 1995 with Salmonella typhimurium WG49 as a host. Survival test continued 28 d for each sub-sample. Viral removal in constructed wetland was more effective than the detention pond system. Survival of somatic coliphages in the inlet and middle of the systems was similar. Slope of declining for outlet of two systems was very slow and completely stable in whole of test duration. Constructed wetland may offer an attractive alternative to stormwater management for reducing the load of disease-causing viruses to the receiving waters.

Use of reflectors to enhance the synergistic effects of solar heating and solar wavelengths to disinfect drinking water sources

Energy Technology Data Exchange (ETDEWEB)

Rijal, G.K. [Metropolitan Water Reclamation District of Greater Chicago, Cicero, Illinois (United States); Fujioka, R.S. [University of Hawaii, Honolulu (United States). Water Resources Research Center

2004-07-01

Aluminum reflectors were added to solar units designed to inactivate faecal microorganisms (faecal coliform, E. coli, enterococci, FRNA coliphage, C. perfringens) in stream water and diluted sewage by the two mechanisms (solar heat, solar UV) known to inactivate microorganisms. During sunny conditions, solar units with and without reflectors inactivated E. coli to <1 CFU/100 ml to meet drinking water standards. Solar units with reflectors disinfected to the water sooner by increasing the water temperature by 8-10{sup o}C to 64-75{sup o}C. However, FRNA coliphages were still detected in these samples, indicating that this treatment may not inactivate pathogenic human enteric viruses. During cloudy conditions, reflectors only increased the water temperature by 3-4{sup o}C to a maximum of 43-49{sup o}C and E. coli was not completely inactivated. Under sunny and cloudy conditions, the UV wavelengths of sunlight worked synergistically with increasing water temperatures and were able to disinfect microorganisms at temperatures (45-56{sup o}C), which were not effective in inactivating microorganisms. Relative resistance to the solar disinfecting effects were C perfringens > FRNA coliphages > enterococci >E. coli > faecal coliform. (author)

Comparação entre hipoclorito de sódio e ácido peracético na inativação de E. coli, colifagos e C. perfringens em água com elevada concentração de matéria orgânica Comparison between sodium hipoclorite and peracetic acid for E. coli, coliphages and C. perfringens inactivation of high organic matter concentration water

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Jeanette Beber de Souza

2005-06-01

evaluated comparing the inactivation of three indicator microorganisms: Escherichia coli ATCC 11229, coliphages and Clostridium perfringens ATCC 13124 previously cultivated and inoculated to the water just before the essay. The Chlorine and peracetic acid concentrations applied was 2.0, 3.0, 4.0 and 5.0 mg/L each of them with contact time of 5, 10, 15 and 20 minutes. When applying 3.0 mg/L of chlorine 3 log inactivation of E. coli with 20 minutes contact time, 2.92 log inactivation of coliphages with 10 minutes contact time and 2 log inactivation of C. perfringens with 15 minutes contact time was obtained. The peracetic acid was effective for the inactivation of all indicator microorganisms even to water with high concentration organic matter. Using peracetic acid dosage of 5 mg/L more than 6 log inactivation of E. coli with 15 minutes contact time, more than 5 log inactivation of coliphages with 20 minutes contact time and more than 4 log inactivation of C. perfringens with 10 minutes contact time was obtained.

Enterococcus phages as potential tool for identifying sewage inputs in the Great Lakes region

Science.gov (United States)

Vijayavel, K.; Byappanahalli, Muruleedhara N.; Whitman, Richard L.; Ebdon, J.; Taylor, H.; Kashian, D.R.

2014-01-01

Bacteriophages are viruses living in bacteria that can be used as a tool to detect fecal contamination in surface waters around the world. However, the lack of a universal host strain makes them unsuitable for tracking fecal sources. We evaluated the suitability of two newly isolated Enterococcus host strains (ENT-49 and ENT-55) capable for identifying sewage contamination in impacted waters by targeting phages specific to these hosts. Both host strains were isolated from wastewater samples and identified as E. faecium by 16S rRNA gene sequencing. Occurrence of Enterococcus phages was evaluated in sewage samples (n = 15) from five wastewater treatment plants and in fecal samples from twenty-two species of wild and domesticated animals (individual samples; n = 22). Levels of Enterococcus phages, F + coliphages, Escherichia coli and enterococci were examined from four rivers, four beaches, and three harbors. Enterococcus phages enumeration was at similar levels (Mean = 6.72 Log PFU/100 mL) to F + coliphages in all wastewater samples, but were absent from all non-human fecal sources tested. The phages infecting Enterococcus spp. and F + coliphages were not detected in the river samples (detection threshold < 10 PFU/100 mL), but were present in the beach and harbor samples (range = 1.83 to 2.86 Log PFU/100 mL). Slightly higher concentrations (range = 3.22 to 3.69 Log MPN/100 mL) of E. coli and enterococci when compared to F + coliphages and Enterococcus phages, were observed in the river, beach and harbor samples. Our findings suggest that the bacteriophages associated with these particular Enterococcus host strains offer potentially sensitive and human-source specific indicators of enteric pathogen risk.

Microbiological Study in Coastal Water of Port Dickson, Malaysia

International Nuclear Information System (INIS)

Ainon Hamzah; Saiful Hazwa Kipli; Siti Rahil Ismail; Rawlins Una; Sukiman Sarmani

2011-01-01

The microbial composition in coastal water of the Port Dickson beach in Negeri Sembilan, Malaysia was analyzed using several microbial indicators for the purpose of selecting the best indicator for marine water pollution. The indicators studied were total coliform (TC), fecal coliform (FC), fecal streptococci (FS) and coliphage. Five locations were selected along the Port Dickson beaches and samplings were carried out in 1998 and 2001. The results showed an increase in the number of total coliform (TC), fecal coliform (FC) and fecal streptococci (FS) between these two sampling by 98.12 %, 86.12 % and 99 %, respectively. The numbers of TC, FC and FS exceeded the recommended limit for recreational seawater based on U.S. EPA 1986 standard. There was a positive correlation between TC, FC and FS and negative to coliphages. (author)

Pulsed high voltage electric discharge disinfection of microbially contaminated liquids.

Science.gov (United States)

Anpilov, A M; Barkhudarov, E M; Christofi, N; Kop'ev, V A; Kossyi, I A; Taktakishvili, M I; Zadiraka, Y

2002-01-01

To examine the use of a novel multielectrode slipping surface discharge (SSD) treatment system, capable of pulsed plasma discharge directly in water, in killing micro-organisms. Potable water containing Escherichia coli and somatic coliphages was treated with pulsed electric discharges generated by the SSD. The SSD system was highly efficient in the microbial disinfection of water with a low energy utilization (eta approximately 10-4 kW h l-1). The SSD treatment was effective in the destruction of E. coli and its coliphages through the generation of u.v. radiation, ozone and free radicals. The non-thermal treatment method can be used for the eradication of micro-organisms in a range of contaminated liquids, including milk, negating the use of pasteurization. The method utilizes multipoint electric discharges capable of treating large volumes of liquid under static and flowing regimes.

Leaching of viruses and other microorganisms naturally occurring in pig slurry to tile drains on a well-structured loamy field in Denmark

DEFF Research Database (Denmark)

Krog, Jesper Schak; Forslund, Anita; Larsen, Lars Erik

2017-01-01

The amount of animal manure used in modern agriculture is increasing due to the increase in global animal production. Pig slurry is known to contain zoonotic bacteria such as E. coli, Salmonella spp. and Campylobacter spp., and viruses such as hepatitis E virus and group A rotavirus. Coliform...... sets out to investigate the leaching potential of six different microorganisms: E. coli and Enterococcus spp. (detected by colony assay), somatic coliphages (using plaque assays), and hepatitis E virus, porcine circovirus type 2, and group A rotavirus (by real-time polymerase chain reaction). All six...... microorganisms leached through the soil entering the tile drains situated at 1-m depth the first day following pig slurry application. The leaching pattern of group A rotavirus differed substantially from the pattern for somatic coliphages, which are otherwise used as indicators for virus contamination...

Studies to distinguish between human and animal faecal pollution ...

African Journals Online (AJOL)

In this study the application of F-RNA coliphages and faecal sterols to distinction between human and animal excreta has .... in a shaking water bath (LABOTEC) at 100 r·min-1. .... calibration standards that were plotted using Microsoft Excel.

Human virus and microbial indicator occurrence in public-supply groundwater systems: meta-analysis of 12 international studies

Science.gov (United States)

Fout, G. Shay; Borchardt, Mark A.; Kieke, Burney A.; Karim, Mohammad R.

2017-06-01

Groundwater quality is often evaluated using microbial indicators. This study examines data from 12 international groundwater studies (conducted 1992-2013) of 718 public drinking-water systems located in a range of hydrogeological settings. Focus was on testing the value of indicator organisms for identifying virus-contaminated wells. One or more indicators and viruses were present in 37 and 15% of 2,273 samples and 44 and 27% of 746 wells, respectively. Escherichia coli ( E. coli) and somatic coliphage are 7-9 times more likely to be associated with culturable virus-positive samples when the indicator is present versus when it is absent, while F-specific and somatic coliphages are 8-9 times more likely to be associated with culturable virus-positive wells. However, single indicators are only marginally associated with viruses detected by molecular methods, and all microbial indicators have low sensitivity and positive predictive values for virus occurrence, whether by culturable or molecular assays, i.e., indicators are often absent when viruses are present and the indicators have a high false-positive rate. Wells were divided into three susceptibility subsets based on presence of (1) total coliform bacteria or (2) multiple indicators, or (3) location of wells in karst, fractured bedrock, or gravel/cobble settings. Better associations of some indicators with viruses were observed for (1) and (3). Findings indicate the best indicators are E. coli or somatic coliphage, although both indicators may underestimate virus occurrence. Repeat sampling for indicators improves evaluation of the potential for viral contamination in a well.

Hygienization performances of innovative sludge treatment solutions to assure safe land spreading.

Science.gov (United States)

Levantesi, C; Beimfohr, C; Blanch, A R; Carducci, A; Gianico, A; Lucena, F; Tomei, M C; Mininni, G

2015-05-01

The present research aims at the evaluation of the hygienization performances of innovative sludge treatment processes applied for the separated treatment of secondary sludge. Namely, two digestion pretreatments (sonication and thermal hydrolysis) and two sequential biological processes (mesophilic/thermophilic and anaerobic/aerobic digestion) were compared to the mesophilic (MAD) and thermophilic anaerobic digestion (TAD). Microbial indicators (Escherichia coli, somatic coliphages and Clostridium perfringens spores) and pathogens (Salmonella and enteroviruses), which show different resistances to treatment processes, were monitored in untreated and treated sludge. Overall, microbial load in secondary sludge was shown to be similar or lower than previously reported in literature for mixed sludge. Notably, the anaerobic/aerobic digestion process increased the removal of E. coli and somatic coliphages compared to the simple MAD and always achieved the hygienization requirement (2-log-unit removal of E. coli) proposed by EU Commission in the 3rd Working Document on sludge (April 2000) for the use of treated sludges in agriculture with restriction on their application. The microbial quality limits for the unrestricted use of sludge in agriculture (no Salmonella in 50 g wet weight (WW) and E. coli <500 CFU/g) were always met when thermal digestion or pretreatment was applied; however, the required removal level (6-log-unit removal of E. coli) could not be assessed due to the low level of this microorganism in raw sludge. Observed levels of indicator removal showed a higher resistance of viral particles to thermal treatment compared with bacterial cells and confirmed the suitability of somatic coliphages as indicators in thermal treatment processes.

Evaluating UV-C LED disinfection performance and investigating potential dual-wavelength synergy

Science.gov (United States)

This study evaluated ultraviolet (UV) light emitting diodes (LEDs) emitting at 260 nm, 280 nm, and the combination of 260|280 nm together for their efficacy at inactivating Escherichia. coli, MS2 coliphage, human adenovirus type 2 (HAdV2), and Bacillus pumilus spores; research in...

76 FR 20542 - Escherichia coli

Science.gov (United States)

2011-04-13

... beef, Escherichia coli and coliphages were found in chicken, fresh pork, fresh oyster, fresh mushrooms, lettuce, chicken pot pie, biscuit dough, deli loaf, deli roasted turkey, and package roasted chicken... surfaces, and in foods such as ground beef, pork sausage, chicken, oysters, cheese, fresh mushrooms, and...

Quantifying viruses and bacteria in wastewater—Results, interpretation methods, and quality control

Science.gov (United States)

Francy, Donna S.; Stelzer, Erin A.; Bushon, Rebecca N.; Brady, Amie M.G.; Mailot, Brian E.; Spencer, Susan K.; Borchardt, Mark A.; Elber, Ashley G.; Riddell, Kimberly R.; Gellner, Terry M.

2011-01-01

Membrane bioreactors (MBR), used for wastewater treatment in Ohio and elsewhere in the United States, have pore sizes small enough to theoretically reduce concentrations of protozoa and bacteria, but not viruses. Sampling for viruses in wastewater is seldom done and not required. Instead, the bacterial indicators Escherichia coli (E. coli) and fecal coliforms are the required microbial measures of effluents for wastewater-discharge permits. Information is needed on the effectiveness of MBRs in removing human enteric viruses from wastewaters, particularly as compared to conventional wastewater treatment before and after disinfection. A total of 73 regular and 28 quality-control (QC) samples were collected at three MBR and two conventional wastewater plants in Ohio during 23 regular and 3 QC sampling trips in 2008-10. Samples were collected at various stages in the treatment processes and analyzed for bacterial indicators E. coli, fecal coliforms, and enterococci by membrane filtration; somatic and F-specific coliphage by the single agar layer (SAL) method; adenovirus, enterovirus, norovirus GI and GII, rotavirus, and hepatitis A virus by molecular methods; and viruses by cell culture. While addressing the main objective of the study-comparing removal of viruses and bacterial indicators in MBR and conventional plants-it was realized that work was needed to identify data analysis and quantification methods for interpreting enteric virus and QC data. Therefore, methods for quantifying viruses, qualifying results, and applying QC data to interpretations are described in this report. During each regular sampling trip, samples were collected (1) before conventional or MBR treatment (post-preliminary), (2) after secondary or MBR treatment (post-secondary or post-MBR), (3) after tertiary treatment (one conventional plant only), and (4) after disinfection (post-disinfection). Glass-wool fiber filtration was used to concentrate enteric viruses from large volumes, and small

Evaluating UV-C LED disinfection performance and ...

Science.gov (United States)

This study evaluated ultraviolet (UV) light emitting diodes (LEDs) emitting at 260 nm, 280 nm, and the combination of 260|280 nm together for their efficacy at inactivating Escherichia. coli, MS2 coliphage, human adenovirus type 2 (HAdV2), and Bacillus pumilus spores; research included an evaluation of genomic damage. Inactivation by the LEDs was compared with the efficacy of conventional UV sources, the low-pressure (LP) and medium-pressure (MP) mercury vapor lamps. The work also calculated the electrical energy per order of reduction of the microorganisms by the five UV sources.For E. coli, all five UV sources yielded similar inactivation rates. For MS2 coliphage, the 260 nm LED was most effective. For HAdV2 and B. pumilus, the MP UV lamp was significantly more effective than the LP UV and UVC LED sources. When considering electrical energy per order of reduction, the LP UV lamp was the most efficient for E. coli and MS2, and the MPUV and LPUV were equally efficient for HAdV2 and B. pumilus spores. Among the UVC LEDs, the 280 nm LED unit required the least energy per log reduction of E. coli and HAdV2. The 280 nm and 260|280 nm LED units were equally efficient per log reduction of B. pumilus spores, and the 260 nm LED unit required the lowest energy per order of reduction of MS2 coliphage. The combination of the 260 nm and 280 nm UV LED wavelengths was also evaluated for potential synergistic effects. No dual-wavelength synergy was detected for inactivation of

Ground-water quality and discharge to Chincoteague and Sinepuxent Bays adjacent to Assateague Island National Seashore, Maryland

Science.gov (United States)

Dillow, Jonathan J.A.; Banks, William S.L.; Smigaj, Michael J.

2002-01-01

The U.S. Geological Survey, in cooperation with the Maryland Department of the Environment and the Wisconsin State Laboratory of Hygiene, conducted a study to characterize the occurrence and distribution of viral contamination in small (withdrawing less than 10,000 gallons per day) public water-supply wells screened in the shallow aquifer in the Piedmont Physiographic Province in Baltimore and Harford Counties, Maryland. Two hundred sixty-three small public water-supply wells were in operation in these counties during the spring of 2000. Ninety-one of these sites were selected for sampling using a methodology that distributed the samples evenly over the population and the spatial extent of the study area. Each site, and its potential susceptibility to microbiological contamination, was evaluated with regard to hole depth, casing interval, and open interval. Each site was evaluated using characteristics such as on-site geology and on-site land use.Samples were collected by pumping between 200 and 400 gallons of untreated well water through an electropositive cartridge filter. Water concentrates were subjected to cell-culture assay for the detection of culturable viruses and reverse-transcription polymerase chain reaction/gene probe assays to detect viral ribonucleic acid; grab samples were analyzed for somatic and male-specific coliphages, Bacteroides fragilis, Clostridium perfringens, enterococci, Escherichia coli, total coliforms, total oxidized nitrogen, nitrite, organic nitrogen, total phosphate, ortho-phosphate, calcium, magnesium, sodium, potas-sium, chloride, sulfate, iron, acid-neutralizing capacity, pH, specific conductance, temperature, and dissolved oxygen.One sample tested positive for the presence of the ribonucleic acid of rotavirus through poly-merase chain-reaction analysis. Twenty-nine per-cent of the samples (26 of 90) had bacterial con-tamination. About 7 percent of the samples (6 of 90) were contaminated with either male-specific coliphage

Occurrence and distribution of microbiological contamination and enteric viruses in shallow ground water in Baltimore and Harford counties, Maryland

Science.gov (United States)

Banks, William S.L.; Battigelli, David A.

2002-01-01

The U.S. Geological Survey, in cooperation with the Maryland Department of the Environment and the Wisconsin State Laboratory of Hygiene, conducted a study to characterize the occurrence and distribution of viral contamination in small (withdrawing less than 10,000 gallons per day) public water-supply wells screened in the shallow aquifer in the Piedmont Physiographic Province in Baltimore and Harford Counties, Maryland. Two hundred sixty-three small public water-supply wells were in operation in these counties during the spring of 2000. Ninety-one of these sites were selected for sampling using a methodology that distributed the samples evenly over the population and the spatial extent of the study area. Each site, and its potential susceptibility to microbiological contamination, was evaluated with regard to hole depth, casing interval, and open interval. Each site was evaluated using characteristics such as on-site geology and on-site land use.Samples were collected by pumping between 200 and 400 gallons of untreated well water through an electropositive cartridge filter. Water concentrates were subjected to cell-culture assay for the detection of culturable viruses and reverse-transcription polymerase chain reaction/gene probe assays to detect viral ribonucleic acid; grab samples were analyzed for somatic and male-specific coliphages, Bacteroides fragilis, Clostridium perfringens, enterococci, Escherichia coli, total coliforms, total oxidized nitrogen, nitrite, organic nitrogen, total phosphate, ortho-phosphate, calcium, magnesium, sodium, potas-sium, chloride, sulfate, iron, acid-neutralizing capacity, pH, specific conductance, temperature, and dissolved oxygen.One sample tested positive for the presence of the ribonucleic acid of rotavirus through poly-merase chain-reaction analysis. Twenty-nine per-cent of the samples (26 of 90) had bacterial con-tamination. About 7 percent of the samples (6 of 90) were contaminated with either male-specific coliphage

Radiochemical identification of the kil gene product of bacteriophage lambda

International Nuclear Information System (INIS)

Greer, H.; Ausubel, F.M.

1979-01-01

The coliphage lambda kil gene product has been identified using a differential labeling technique . The kil gene polypeptide has a molecular weight of about 16,000, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Gel filtration of the kil protein indicates that it may exist as a tetramer in native form

40 CFR 141.402 - Ground water source microbial monitoring and analytical methods.

Science.gov (United States)

2010-07-01

... approves the use of E. coli as a fecal indicator for source water monitoring under this paragraph (a). If the repeat sample collected from the ground water source is E.coli positive, the system must comply... listed in the in paragraph (c)(2) of this section for the presence of E. coli, enterococci, or coliphage...

Removal of micro-organisms in a small-scale hydroponics wastewater treatment system.

Science.gov (United States)

Ottoson, J; Norström, A; Dalhammar, G

2005-01-01

To measure the microbial removal capacity of a small-scale hydroponics wastewater treatment plant. Paired samples were taken from untreated, partly-treated and treated wastewater and analysed for faecal microbial indicators, i.e. coliforms, Escherichia coli, enterococci, Clostridium perfringens spores and somatic coliphages, by culture based methods. Escherichia coli was never detected in effluent water after >5.8-log removal. Enterococci, coliforms, spores and coliphages were removed by 4.5, 4.1, 2.3 and 2.5 log respectively. Most of the removal (60-87%) took place in the latter part of the system because of settling, normal inactivation (retention time 12.7 d) and sand filtration. Time-dependent log-linear removal was shown for spores (k = -0.17 log d(-1), r(2) = 0.99). Hydroponics wastewater treatment removed micro-organisms satisfactorily. Investigations on the microbial removal capacity of hydroponics have only been performed for bacterial indicators. In this study it has been shown that virus and (oo)cyst process indicators were removed and that hydroponics can be an alternative to conventional wastewater treatment.

Selective accumulation may account for shellfish-associated viral illness.

Science.gov (United States)

Burkhardt, W; Calci, K R

2000-04-01

From 1991 through 1998, 1,266 cases of shellfish-related illnesses were attributed to Norwalk-like viruses. Seventy-eight percent of these illnesses occurred following consumption of oysters harvested from the Gulf Coast during the months of November through January. This study investigated the ability of eastern oysters (Crassostrea virginica) to accumulate indicator microorganisms (i.e., fecal coliforms, Escherichia coli, Clostridium perfringens, and F(+) coliphage) from estuarine water. One-week trials over a 1-year period were used to determine if these indicator organisms could provide insight into the seasonal occurrence of these gastrointestinal illnesses. The results demonstrate that oysters preferentially accumulated F(+) coliphage, an enteric viral surrogate, to their greatest levels from late November through January, with a concentration factor of up to 99-fold. However, similar increases in accumulation of the other indicator microorganisms were not observed. These findings suggest that the seasonal occurrence of shellfish-related illnesses by enteric viruses is, in part, the result of seasonal physiological changes undergone by the oysters that affect their ability to accumulate viral particles from estuarine waters.

Assessment of the microbial quality of river water sources in rural ...

African Journals Online (AJOL)

... 1.0 x 101 cfu·ml-1 and 2.5. x 104 cfu·ml-1 for enterococci and 0 and 13 pfu·100 ml-1 for somatic coliphages. The results for the indicators were higher than the acceptable maximum limits prescribed by the Department of Water and Forestry of South Africa. According to these guidelines, the maximum values are as follows: ...

Pathogens and fecal indicators in waste stabilization pond systems with direct reuse for irrigation: Fate and transport in water, soil and crops

Energy Technology Data Exchange (ETDEWEB)

Verbyla, M.E., E-mail: verbylam@mail.usf.edu [Department of Civil and Environmental Engineering, University of South Florida, 4202 E. Fowler Avenue, Tampa, FL (United States); Iriarte, M.M.; Mercado Guzmán, A.; Coronado, O.; Almanza, M. [Centro de Aguas y Saneamiento Ambiental, Universidad Mayor de San Simón, Cochabamba (Bolivia, Plurinational State of); Mihelcic, J.R. [Department of Civil and Environmental Engineering, University of South Florida, 4202 E. Fowler Avenue, Tampa, FL (United States)

2016-05-01

Wastewater use for irrigation is expanding globally, and information about the fate and transport of pathogens in wastewater systems is needed to complete microbial risk assessments and develop policies to protect public health. The lack of maintenance for wastewater treatment facilities in low-income areas and developing countries results in sludge accumulation and compromised performance over time, creating uncertainty about the contamination of soil and crops. The fate and transport of pathogens and fecal indicators was evaluated in waste stabilization ponds with direct reuse for irrigation, using two systems in Bolivia as case studies. Results were compared with models from the literature that have been recommended for design. The removal of Escherichia coli in both systems was adequately predicted by a previously-published dispersed flow model, despite more than 10 years of sludge accumulation. However, a design equation for helminth egg removal overestimated the observed removal, suggesting that this equation may not be appropriate for systems with accumulated sludge. To assess the contamination of soil and crops, ratios were calculated of the pathogen and fecal indicator concentrations in soil or on crops to their respective concentrations in irrigation water (termed soil-water and crop-water ratios). Ratios were similar within each group of microorganisms but differed between microorganism groups, and were generally below 0.1 mL g{sup −1} for coliphage, between 1 and 100 mL g{sup −1} for Giardia and Cryptosporidium, and between 100 and 1000 mL g{sup −1} for helminth eggs. This information can be used for microbial risk assessments to develop safe water reuse policies in support of the United Nations' 2030 Sustainable Development Agenda. - Highlights: • Study of health risks from reclaimed wastewater irrigation from aging pond systems • Coliphages, protozoan parasites, and helminths were measured in water/soil/crops. • Sludge accumulation in

Pathogens and fecal indicators in waste stabilization pond systems with direct reuse for irrigation: Fate and transport in water, soil and crops

International Nuclear Information System (INIS)

Verbyla, M.E.; Iriarte, M.M.; Mercado Guzmán, A.; Coronado, O.; Almanza, M.; Mihelcic, J.R.

2016-01-01

Wastewater use for irrigation is expanding globally, and information about the fate and transport of pathogens in wastewater systems is needed to complete microbial risk assessments and develop policies to protect public health. The lack of maintenance for wastewater treatment facilities in low-income areas and developing countries results in sludge accumulation and compromised performance over time, creating uncertainty about the contamination of soil and crops. The fate and transport of pathogens and fecal indicators was evaluated in waste stabilization ponds with direct reuse for irrigation, using two systems in Bolivia as case studies. Results were compared with models from the literature that have been recommended for design. The removal of Escherichia coli in both systems was adequately predicted by a previously-published dispersed flow model, despite more than 10 years of sludge accumulation. However, a design equation for helminth egg removal overestimated the observed removal, suggesting that this equation may not be appropriate for systems with accumulated sludge. To assess the contamination of soil and crops, ratios were calculated of the pathogen and fecal indicator concentrations in soil or on crops to their respective concentrations in irrigation water (termed soil-water and crop-water ratios). Ratios were similar within each group of microorganisms but differed between microorganism groups, and were generally below 0.1 mL g"−"1 for coliphage, between 1 and 100 mL g"−"1 for Giardia and Cryptosporidium, and between 100 and 1000 mL g"−"1 for helminth eggs. This information can be used for microbial risk assessments to develop safe water reuse policies in support of the United Nations' 2030 Sustainable Development Agenda. - Highlights: • Study of health risks from reclaimed wastewater irrigation from aging pond systems • Coliphages, protozoan parasites, and helminths were measured in water/soil/crops. • Sludge accumulation in ponds may limit

Water and Wastewater Disinfection with Peracetic Acid and UV Radiation and Using Advanced Oxidative Process PAA/UV

OpenAIRE

Beber de Souza, Jeanette; Queiroz Valdez, Fernanda; Jeranoski, Rhuan Felipe; Vidal, Carlos Magno de Sousa; Cavallini, Grasiele Soares

2015-01-01

The individual methods of disinfection peracetic acid (PAA) and UV radiation and combined process PAA/UV in water (synthetic) and sanitary wastewater were employed to verify the individual and combined action of these advanced oxidative processes on the effectiveness of inactivation of microorganisms indicators of fecal contamination E. coli, total coliforms (in the case of sanitary wastewater), and coliphages (such as virus indicators). Under the experimental conditions investigated, doses o...

Reduction of Cryptosporidium, Giardia, and Fecal Indicators by Bardenpho Wastewater Treatment.

Science.gov (United States)

Schmitz, Bradley W; Moriyama, Hitoha; Haramoto, Eiji; Kitajima, Masaaki; Sherchan, Samendra; Gerba, Charles P; Pepper, Ian L

2018-06-19

Increased demand for water reuse and reclamation accentuates the importance for optimal wastewater treatment to limit protozoa in effluents. Two wastewater treatment plants utilizing advanced Bardenpho were investigated over a 12-month period to determine the incidence and reduction of Cryptosporidium, Giardia, Cyclospora, and fecal indicators. Results were compared to facilities that previously operated in the same geographical area. Protozoa (oo)cysts were concentrated using an electronegative filter and subsequently detected by fluorescent microscopy and/or PCR methods. Cryptosporidium and Giardia were frequently detected in raw sewage, but Cyclospora was not detected in any wastewater samples. Facilities with Bardenpho treatment exhibited higher removals of (oo)cysts than facilities utilizing activated sludge or trickling filters. This was likely due to Bardenpho systems having increased solid wasting rates; however, this mechanism cannot be confirmed as sludge samples were not analyzed. Use of dissolved-air-flotation instead of sedimentation tanks did not result in more efficient removal of (oo)cysts. Concentrations of protozoa were compared with each other, Escherichia coli, somatic coliphage, and viruses (pepper mild mottle virus, Aichi virus 1, adenovirus, and polyomaviruses JC and BK). Although significant correlations were rare, somatic coliphage showed the highest potential as an indicator for the abundance of protozoa in wastewaters.

Comparative study on the efficiency of peracetic acid and chlorine dioxide at low doses in the disinfection of urban wastewaters.

Science.gov (United States)

De Luca, Giovanna; Sacchetti, Rossella; Zanetti, Franca; Leoni, Erica

2008-01-01

A comparison was made between the efficiency of low doses of peracetic acid (PAA: 1.5 mg/l) and chlorine dioxide (ClO(2): 1.5 and 2.0 mg/l) in the disinfection of secondary effluents of a wastewater treatment plant. Peracetic acid was seen to be more active than chlorine dioxide and less influenced by the organic content of the waste. Both PAA and ClO(2) (2.0 mg/l) lead to a higher reduction in total and faecal coliforms and E. coli than in phages (somatic coliphages and F-specific RNA bacteriophages) and enterococci. Detection of faecal coliforms and E. coli should therefore be accompanied by a search for these more resistant microorganisms when assessing the conformity of wastewater for irrigation use, or for discharge into surface waters. Coliphages are also considered suitable indicators of the presence of enteric viruses. Although the application of low doses of both disinfectants offers advantages in terms of costs and produces not significant quantities of byproducts, it is not sufficient to obtain wastewater suitable for irrigation according to the Italian norms (E. coli < 10/100 ml in 80 % of samples and <100/100 ml in the remaining samples). Around 65 % of the samples, however, presented concentrations of E. coli lower than the limit of 5,000/100 ml established by Italian norms for discharge into surface waters.

Mechanisms for parasites removal in a waste stabilisation pond.

Science.gov (United States)

Reinoso, Roberto; Blanco, Saúl; Torres-Villamizar, Linda A; Bécares, Eloy

2011-04-01

A waste stabilisation pond (WSP) system formed by two anaerobic ponds, a facultative pond and a maturation pond was studied from December 2003 to September 2004 in north-western Spain in order to evaluate its efficiency in the removal of faecal indicator bacteria (total coliforms, Escherichia coli, faecal streptococci), coliphages, helminth eggs and protozoan (oo)cysts (Cryptosporidium and Giardia). Furthermore, sediment samples were collected from the bottom of the ponds to assess the settling rates and thus determine the main pathogen removal mechanisms in the WSPs system. The overall removal ranged from 1.4 log units for coliphages in the cold period to 5.0 log units for E. coli in the hot period. Cryptosporidium oocysts were reduced by an average of 96%, Giardia cysts by 98% and helminth eggs by 100%. The anaerobic ponds showed significantly higher surface removal rates (4.6, 5.2 and 3.7 log (oo)cysts/eggs removed m(-2) day(-1), respectively) than facultative and maturation ponds. Sunlight and water physicochemical conditions were the main factors influencing C. parvum oocysts removal both in the anaerobic and maturation ponds, whereas other factors like predation or natural mortality were more important in the facultative pond. Sedimentation, the most commonly proposed mechanism for cyst removal had, therefore, a negligible influence in the studied ponds.

Microbiological and chemical quality of ground water used as a source of public supply in southern Missouri : Phase II, April-July, 1998

Science.gov (United States)

Femmer, Suzanne R.

2000-01-01

included comparing and contrasting the data by grouping according to well age and construction, karst type, geohydrology, soil type, and land use. There was little variation in well construction between selected wells. The results indicated several groupings of similar and dissimilar concentrations, most expected because of hydrological, physical, or land use differences. Dissolved oxygen values indicated distinct variation in the different groupings. There were significant differences in dissolved oxygen values between the secondary and non-karst areas, the Ozark confined and Ozark unconfined geohydrologic groups, and between agricultural and other land uses. In groupings by soil and geohydrology, the Missouri bootheel region differed with respect to ammonia, total organic carbon, and phosphorus when compared with the other groups. Less than 10 percent of the wells sampled tested positive for bacterial contamination. E. coli was the most frequently detected bacterium. The public wells at Monett and West Plains, Missouri, had plates with colonies too numerous to count for all three indicator bacteria. Further analyses by rRNA (ribosomal RiboNucleic Acid) hybridization techniques detennined that much of the bacteria present were from ruminant and human sources. No enteric viruses were detected in the 109 samples. Both ribonucleic acid and somatic coliphage were detected at two wells. One additional well had ribonucleic acid coliphage and another had somatic coliphage for a total of four wells with coliphage selects.

Inactivation of viruses in municipal effluent by chlorine.

OpenAIRE

Hajenian, H. G.; Butler, M.

1980-01-01

The influence of pH and temperature on the efficiency of chlorine inactivation of two unrelated picornaviruses in a typical urban wastewater effluent was examined. Temperature, unlike pH, had relatively little effect on the rate of inactivation. The pH effect was complex and the two viruses differed. The f2 coliphage was more sensitive to chlorine at low pH, but at all values there was a threshold above which additional chlorine resulted in very rapid inactivation. The amount of chlorine requ...

Use of germicidal lamps in the disinfection of sanitary wastewater

Directory of Open Access Journals (Sweden)

Patrícia Bilotta

2012-04-01

Full Text Available The objective of this study was to investigate the efficiency of germicidal lamps in the tertiary treatment of sewage to control pathogens. The performance of the photochemical reactor used in the tests was monitored by microbiological analyses to quantify E. coli (bacteria indicator, C. perfringens (protozoa indicator, coliphages (virus indicator. The experiments were performed with effluent from an UASB reactor installed at the WTP- USP São Carlos campus subjected to an aerated submerged biological filter and a photochemical reactor with radiation UV at 254 nm. The results showed that the indicators coliphages and E. coli showed the least resistance to UV radiation reaching removal from 1.70 to 3.90 log and 1.60 to 5.20 log, respectively. On the other hand, the indicator C. perfringens was more resistant to the effect of germicidal lamps reaching values between 0.0 (no inactivation and 1.30 log. For SST concentrations greater than 100.0 mg.L-1, the effect of the germicidal lamps became less pronounced. However, in practice it was possible to notice significant results in tests with TSS concentrations of 135.0 mg.L-1. The experimental approach proved the usefulness of the combined method for inactivating pathogens commonly found in domestic sewage. Besides meeting the standards established by the Brazilian regulation, the final effluent is in agreement with the guidelines defined by WHO. This allows the reuse of the final effluent for unrestricted irrigation, although complementary examination must be performed.

Occurrence and numbers of bacteriophages and bacterial indicators in faeces of yellow-legged seagull (Larus cachinnans).

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Muniesa, M; Jofre, J; Lucena, F

1999-12-01

Faeces from feral populations of yellow-legged seagulls from the northern coastal area of Catalonia (North-eastern Spain) contained variable amounts of faecal coliforms, faecal streptococci, somatic coliphages, F-specific bacteriophages and Bacteroides fragilis bacteriophages. Occurrence and numbers of bacterial indicators and bacteriophages in the faeces of yellow-legged seagulls are in the ranges described in the faeces of different animals. The ratios between numbers of bacterial indicators and numbers of bacteriophages are much higher in faeces of seagulls than in treated or raw sewage contributed by out-falls of the same area.

Microbiological indicators of water quality in the Xochimilco canals, Mexico City.

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Juárez-Figueroa, Luis Alfredo; Silva-Sánchez, Jesús; Uribe-Salas, Felipe Javier; Cifuentes-García, Enrique

2003-01-01

To quantify microbiology indicators of fecal contamination in the effluents of two waste water treatment plants and in samples collected in several canals in Xochimilco. A cross sectional study was performed. Ten sites, 5 from plant effluents and 5 from canals, were selected for sampling during November and December 2001. Fecal coliforms and enterococci were quantified by membrane filtration, male specific (F+) and somatic coliphages by double agar layer technique, and Cryptosporidium oocysts and Giardia cysts by concentration with Envirocheck filter followed by immunofluorescence microscopy quantification. The average of organisms counts from effluents and canal water were compared with t Student test. Treated water discharge in canals showed a low count of Fecal Coliforms (average 40.4/100 ml), enterococci (average 58.8/100 ml) and Cryptosporidium oocysts (average 13.2/100 l), while coliphages and Giardia cyst rendered higher counts (average 1467.5/100 ml and 1199.8/100 l, respectively) suggesting the water treatment methods could fail to remove these agents. A significant lower count of Giardia cysts (average 45/100 l) and no Cryptosporidium oocysts were found in irrigation canals, which suggests a natural clearance of these pathogens. Strains of Escherichia coli isolated in one of the canals contaminated with sewage had antimicrobial multi-resistance that was transferred by conjugation suggesting that resistance is encoded in a plasmid potentially transferable to other pathogenic bacteria. Cost effective and culturally acceptable waste treatment methods will require careful planning and consultation if they are to be adopted and mantained by local populations.

Fate of indicator microorganisms under nutrient management plan conditions.

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Bradford, Scott A; Segal, Eran

2009-01-01

Nutrient management plans (NMPs) for application of wastewater from concentrated animal feeding operations are designed to meet crop water and nutrient requirements, but implicitly assume that pathogenic microorganisms in the wastewater will be retained and die-off in the root zone. A NMP was implemented on a field plot to test this assumption by monitoring the fate of several fecal indicator microorganisms (Enterococcus, fecal coliforms, somatic coliphage, and total Escherichia coli). When well-water and wastewater were applied to meet measured evapotranspiration (ET), little advective transport of the indicator microorganisms occurred below the root zone and the remaining microorganisms rapidly died-off (within 1 mo). Additional experiments were conducted in the laboratory to better quantify microorganism transport and survival in the field soil. Batch survival experiments revealed much more rapid die-off rates for the bacterial indicator microorganisms in native than in sterilized soil, suggesting that biotic factors controlled survival. Saturated column experiments with packed field soil, demonstrated much greater transport potential for somatic coliphage than bacterial indicators (Enterococcus and total E. coli) and that the retention rates for the indicator microorganisms were not log-linear with depth. A worst case transport scenario of ponded infiltration on a large undistributed soil column from the field was also initiated and indicator microorganisms were not detected in the column outflow or in the soil at a depth of 65 cm. All of these observations support the hypothesis that a NMP at this site will protect groundwater supplies from microorganism contamination, especially when applied water and wastewater meet ET.

Physical-chemicals parameters and microbiological indicators in sewage treatment of Ciudad Real; Parametros fisicoquimicos e indicadores microbiologicos en la depuracion de aguas residuales de Ciudad Real

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Lopez Solanilla, E.; Ubeda Iranzo, J.F.; Perez Bencecry, C. [E.U.I. Tecnica Agricola. Ciudad Real. Universidad de Castilla-La Mancha (Spain)

1997-05-01

The aim of this work is to find out the possible relationship between some physico-chemical (pH, conductivity dissolved oxygen, suspended solids, DBO, DQO) and sanitary microbiological parameters (total coliforms, faecal coliforms, faecal streptococcus , coliphages) in a sewage treatment. It was carried out in a waste water treatment plant with an activated sludges process of conventional design. The most significative effects that primary treatment and the biological treatment on the parameters analyzed were stablished. On the other hand, effective chlorine doses and contact time were determined for a possible reuse of the treated water. (Author) 16 refs.

Assessment of the use of selected chemical and microbiological constituents as indicators of wastewater in curtain drains from home sewage-treatment systems in Medina County, Ohio

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Dumouchelle, Denise H.

2006-01-01

Many home sewage-treatment systems (HSTS) in Ohio use curtain or perimeter drains to depress the level of the subsurface water in and around the systems. These drains could possibly intercept partially untreated wastewater and release potential pathogens to ground-water and surface-water bodies. The quality of water in curtain drains from two different HSTS designs in Medina County, Ohio, was investigated using several methods. Six evaporation-transpiration-absorption (ETA) and five leach-line (LL) systems were investigated by determining nutrient concentrations, chloride/bromide ratios (Cl/Br), Escherichia coli (E. coli ) concentrations, coliphage genotyping, and genetic fingerprinting of E. coli. Water samples were collected at 11 sites and included samples from curtain drains, septic tanks, and residential water wells. Nitrate concentrations in the curtain drains ranged from 0.03 to 3.53 mg/L (milligrams per liter), as N. Concentrations of chloride in 10 of the 11 curtain drains ranged from 5.5 to 21 mg/L; the chloride concentration in the eleventh curtain drain was 340 mg/L. Bromide concentrations in 11 curtain drains ranged from 0.01 to 0.22 mg/L. Cl/Br ratios ranged from 86 to 2,000. F-specific coliphage were not found in any curtain-drain samples. Concentrations of E. coli in the curtain drains ranged from 1 to 760 colonies per 100 milliliters. The curtain-drain water-quality data were evaluated to determine whether HSTS-derived water was present in the curtain drains. Nutrient concentrations were too low to be of use in the determination. The Cl/Br ratios appear promising. Coliphage was not detected in the curtain drains, so genotyping could not be attempted. E. coli concentrations in the curtain drains were all less than those from the corresponding HSTS; only one sample exceeded the Ohio secondary-contact water-quality standard. The genetic fingerprinting data were inconclusive because multiple links between unrelated sites were found. Although the

Development and field testing of an alternative latrine design utilizing basic oxygen furnace slag as a treatment media for pathogen removal

Science.gov (United States)

Stimson, J.; Suhogusoff, A. V.; Blowes, D. W.; Hirata, R. A.; Ptacek, C. J.; Robertson, W. D.; Emelko, M. B.

2009-05-01

In densely-populated communities in developing countries, appropriate setback distances for pit latrines often cannot be met. An alternative latrine was designed that incorporates two permeable reactive media to treat pathogens and nitrate from effluent. Basic oxygen furnace (BOF) slag in contact with wastewater effluent elevates pH to levels (> 11) that inactivate pathogens. Saturated woodchip creates reducing conditions that encourage the growth of denitrifying bacteria which remove NO3-. The field application was constructed in Santo Antônio, a peri-urban community located 25 km south of the city of São Paulo, Brazil. A 2-m diameter pit was excavated to a depth of 4 m into the sandy-clay unsaturated zone. A geotextile liner was emplaced to create saturated conditions in the 0.5-m thick woodchip barrier. Above the woodchip barrier, a 1-m thick layer of BOF slag mixed with pea gravel and sand was emplaced. A series of filter layers, grading upward from coarse sand to fine gravel, where placed above the BOF layer, and gravel was also infilled around the outer perimeter of the excavation, to ensure O2 diffusion into the design, the formation of biofilm, and degradation of organic material. A control latrine, constructed with similar hydraulic characteristics and nonreactive materials, was constructed at a locality 100 m away, in the same geological materials. Total coliform, thermotolerant coliform, and E. coli are removed by approximately 4-5 log concentration units in less than one meter of vertical transport through the BOF slag media. In the control latrine, comparable reductions in these pathogenic indicators are observed over three meters of vertical transport. Removal of sulphur-reducing Clostridia, Clostridium perfrigens and somatic coliphage are also achieved in the alternative design, but initial concentrations in effluent are low. Some measurable concentrations of pathogen indicators are measured in lysimeters below the BOF layer, but are associated

Reuse of wastewater effluents in Saudi Arabia

International Nuclear Information System (INIS)

Ishaq, A.M.; Al-Suwaiyan, M.S.

2002-01-01

In the initial phase of a six-year study, laboratory investigations were carried out to establish conservative estimates of the contaminant removals that are possible by the recharge of local secondary effluents through a sand dune. In the preliminary laboratory study, chlorinated effluent was found to be more suitable than unchlorinated wastewater with respect to the development of anaerobic conditions and headlosses. In the main laboratory study, a 5-m high Plexiglass sand box column was used to investigate conservative predictions for the removal of contaminants. The average removals of BOD, COD, and TOC were over 65%, 65%, and 55%, respectively. The COD was primarily removed in the first 200 cm of the column. The effluent had a residual TOC of 1.66 mg/l and consisted of humic substances. The average removal of microbial indicator organisms: Total Coliform (TC) and Coliphage were over 85% and 66%, respectively. The product water contained only nominal amounts of TC (Average - 21.5 MPN/100 ml) and Coliphage (Average - 6 PFU/100 ml). The porous media largely remained unaffected by the recharge operation. In the second phase, a 'field recharge system' was constructed and recharge operations were carried out over a two year period resulting in the following observations. a. The quality of the end product will depend entirely on the quality of the secondary effluent. b. With the soil aquifer treatment system (SATS) under consideration, it was possible to achieve product water meeting the recharge standards with respect to heavy metals, pH, BOD, TOC, fecal coliform and total coliform. c. The product water met the standards for restricted and unrestricted irrigation. (author)

Reuse of wastewater effluents in Saudi Arabia

Energy Technology Data Exchange (ETDEWEB)

Ishaq, A.M.; Al-Suwaiyan, M.S. [King Fahd Univ. of Petroleum and Minerals, Dept. of Civil Engineering, Dhahran (Saudi Arabia)

2002-06-15

In the initial phase of a six-year study, laboratory investigations were carried out to establish conservative estimates of the contaminant removals that are possible by the recharge of local secondary effluents through a sand dune. In the preliminary laboratory study, chlorinated effluent was found to be more suitable than unchlorinated wastewater with respect to the development of anaerobic conditions and headlosses. In the main laboratory study, a 5-m high Plexiglass sand box column was used to investigate conservative predictions for the removal of contaminants. The average removals of BOD, COD, and TOC were over 65%, 65%, and 55%, respectively. The COD was primarily removed in the first 200 cm of the column. The effluent had a residual TOC of 1.66 mg/l and consisted of humic substances. The average removal of microbial indicator organisms: Total Coliform (TC) and Coliphage were over 85% and 66%, respectively. The product water contained only nominal amounts of TC (Average - 21.5 MPN/100 ml) and Coliphage (Average - 6 PFU/100 ml). The porous media largely remained unaffected by the recharge operation. In the second phase, a 'field recharge system' was constructed and recharge operations were carried out over a two year period resulting in the following observations. a. The quality of the end product will depend entirely on the quality of the secondary effluent. b. With the soil aquifer treatment system (SATS) under consideration, it was possible to achieve product water meeting the recharge standards with respect to heavy metals, pH, BOD, TOC, fecal coliform and total coliform. c. The product water met the standards for restricted and unrestricted irrigation. (author)

Surveillance of Enteric Viruses and Microbial Indicators in the Eastern Oysters (Crassostrea virginica) and Harvest Waters along Louisiana Gulf Coast.

Science.gov (United States)

Montazeri, Naim; Maite, Morgan; Liu, Da; Cormier, Jiemin; Landry, Matthew; Shackleford, John; Lampila, Lucina E; Achberger, Eric C; Janes, Marlene E

2015-05-01

Noroviruses are the most common causative agent of viral gastroenteritis in humans, and are responsible for major foodborne illnesses in the United States. Filter-feeding molluscan shellfish exposed to sewage-contaminated waters bioaccumulate viruses, and if consumed raw, transmit the viruses to humans and cause illness. We investigated the occurrence of norovirus GI and GII and microbial indicators of fecal contamination in the eastern oysters (Crassostrea virginica) and water from commercial harvesting areas along the Louisiana Gulf Coast (January to November of 2013). Microbial indicators (aerobic plate count, enterococci, fecal coliforms, Escherichia coli, male-specific coliphages, and somatic coliphages) were detected at the densities lower than public health concerns. Only one oyster sample was positive for norovirus GII at 3.5 ± 0.2 log10 genomic equivalent copies/g digestive tissues. A stool specimen obtained from an infected individual associated with a norovirus outbreak and the suspected oysters (Cameron Parish, La., area 30, January 2013) were also analyzed. The norovirus strain in the stool belonged to GII.4 Sydney; however, the oysters were negative and could not be linked. In general, no temporal trend was observed in the microbial indicators. Low correlation among bacterial indicators was observed in oysters. Strongest correlations among microbial indicators were observed between enterococci and fecal coliforms (r = 0.63) and between enterococci and E. coli (r = 0.64) in water (P oysters (r oysters and harvest water (r ≤ 0.36, P > 0.05). Our results emphasize the need for regular monitoring of pathogenic viruses in commercial oyster harvesting areas to reduce the risks of viral gastroenteritis incidences. © 2015 Institute of Food Technologists®

Binding of transcription termination protein nun to nascent RNA and template DNA.

Science.gov (United States)

Watnick, R S; Gottesman, M E

1999-12-17

The amino-terminal arginine-rich motif of coliphage HK022 Nun binds phage lambda nascent transcript, whereas the carboxyl-terminal domain interacts with RNA polymerase (RNAP) and blocks transcription elongation. RNA binding is inhibited by zinc (Zn2+) and stimulated by Escherichia coli NusA. To study these interactions, the Nun carboxyl terminus was extended by a cysteine residue conjugated to a photochemical cross-linker. The carboxyl terminus contacted NusA and made Zn2+-dependent intramolecular contacts. When Nun was added to a paused transcription elongation complex, it cross-linked to the DNA template. Nun may arrest transcription by anchoring RNAP to DNA.

Water quality and sources of fecal coliform bacteria in the Meduxnekeag River, Houlton, Maine

Science.gov (United States)

Culbertson, Charles W.; Huntington, Thomas G.; Stoeckel, Donald M.; Caldwell, James M.; O'Donnell, Cara

2014-01-01

detected at one site (Moose Brook) but was not detected at other sites. Fecal contamination (as indicated by fecal coliform density) apparently is localized under normal flow conditions with the highest levels restricted to drains in urban areas and to a lesser extent B Stream, Pearce Brook, and Big Brook, all tributaries to the main stem of the Meduxnekeag River. Coliphage were enumerated as an alternate indicator of fecal contamination with the intent of typing the virus into host-associated classes (human or ruminant), as was done for Enterococci; however, insufficient coliphage were isolated to provide more than preliminary indications. In spite of low coliphage enumeration, the preliminary results strengthen the conclusion that the Enterococci data correctly indicated the samples that contained human and ruminant fecal contamination. The finding that contamination was in many of the tributaries following storms in mid-July indicates that storm runoff likely carries fecal contaminants to more locations than runoff under lower flow conditions.

Characterization of a ViI-like Phage Specific to Escherichia coli O157:H7

Directory of Open Access Journals (Sweden)

Kropinski Andrew M

2011-09-01

Full Text Available Abstract Phage vB_EcoM_CBA120 (CBA120, isolated against Escherichia coli O157:H7 from a cattle feedlot, is morphologically very similar to the classic phage ViI of Salmonella enterica serovar Typhi. Until recently, little was known genetically or physiologically about the ViI-like phages, and none targeting E. coli have been described in the literature. The genome of CBA120 has been fully sequenced and is highly similar to those of both ViI and the Shigella phage AG3. The core set of structural and replication-related proteins of CBA120 are homologous to those from T-even phages, but generally are more closely related to those from T4-like phages of Vibrio, Aeromonas and cyanobacteria than those of the Enterobacteriaceae. The baseplate and method of adhesion to the host are, however, very different from those of either T4 or the cyanophages. None of the outer baseplate proteins are conserved. Instead of T4's long and short tail fibers, CBA120, like ViI, encodes tail spikes related to those normally seen on podoviruses. The 158 kb genome, like that of T4, is circularly permuted and terminally redundant, but unlike T4 CBA120 does not substitute hmdCyt for cytosine in its DNA. However, in contrast to other coliphages, CBA120 and related coliphages we have isolated cannot incorporate 3H-thymidine (3H-dThd into their DNA. Protein sequence comparisons cluster the putative "thymidylate synthase" of CBA120, ViI and AG3 much more closely with those of Delftia phage φW-14, Bacillus subtilis phage SPO1, and Pseudomonas phage YuA, all known to produce and incorporate hydroxymethyluracil (hmdUra.

Supersize me: Cronobacter sakazakii phage GAP32

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Abbasifar, Reza; Griffiths, Mansel W. [Canadian Research Institute for Food Safety, University of Guelph, Guelph, ON, Canada N1G 2W1 (Canada); Sabour, Parviz M. [Agriculture and Agri-Food Canada, Guelph Food Research Centre, Guelph, ON, Canada N1G 5C9 (Canada); Ackermann, Hans-Wolfgang [Department of Microbiology-Infectiology and Immunology, Faculty of Medicine, Université Laval, Quebec, QC (Canada); Vandersteegen, Katrien; Lavigne, Rob [Laboratory of Gene Technology, Katholieke Universiteit Leuven, Leuven (Belgium); Noben, Jean-Paul [Biomedical Research Institute and Transnational University Limburg, School of Life Sciences, Hasselt University, Diepenbeek (Belgium); Alanis Villa, Argentina; Abbasifar, Arash [Canadian Research Institute for Food Safety, University of Guelph, Guelph, ON, Canada N1G 2W1 (Canada); Nash, John H.E. [Public Health Agency of Canada, Laboratory for Foodborne Zoonoses, Guelph, ON, Canada N1G 3W4 (Canada); Kropinski, Andrew M., E-mail: akropins@uoguelph.ca [Public Health Agency of Canada, Laboratory for Foodborne Zoonoses, Guelph, ON, Canada N1G 3W4 (Canada); Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, Canada N1G 2W1 (Canada)

2014-07-15

Cronobacter sakazakii is a Gram-negative pathogen found in milk-based formulae that causes infant meningitis. Bacteriophages have been proposed to control bacterial pathogens; however, comprehensive knowledge about a phage is required to ensure its safety before clinical application. We have characterized C. sakazakii phage vB{sub C}saM{sub G}AP32 (GAP32), which possesses the second largest sequenced phage genome (358,663 bp). A total of 571 genes including 545 protein coding sequences and 26 tRNAs were identified, thus more genes than in the smallest bacterium, Mycoplasma genitalium G37. BLASTP and HHpred searches, together with proteomic analyses reveal that only 23.9% of the putative proteins have defined functions. Some of the unique features of this phage include: a chromosome condensation protein, two copies of the large subunit terminase, a predicted signal-arrest-release lysin; and an RpoD-like protein, which is possibly involved in the switch from immediate early to delayed early transcription. Its closest relatives are all extremely large myoviruses, namely coliphage PBECO4 and Klebsiella phage vB{sub K}leM-RaK2, with whom it shares approximately 44% homologous proteins. Since the homologs are not evenly distributed, we propose that these three phages belong to a new subfamily. - Highlights: • Cronobacter sakazakii phage vB{sub C}saM{sub G}AP32 has a genome of 358,663 bp. • It encodes 545 proteins which is more than Mycoplasma genitalium G37. • It is a member of the Myoviridae. • It is peripherally related to coliphage PBECO4 and Klebsiella phage vB{sub K}leM-RaK2. • GAP32 encodes a chromosome condensation protein.

Inactivation of microbiota from urban wastewater by single and sequential electrocoagulation and electro-Fenton treatments.

Science.gov (United States)

Anfruns-Estrada, Eduard; Bruguera-Casamada, Carmina; Salvadó, Humbert; Brillas, Enric; Sirés, Ignasi; Araujo, Rosa M

2017-12-01

This work aims at comparing the ability of two kinds of electrochemical technologies, namely electrocoagulation (EC) and electro-Fenton (EF), to disinfect primary and secondary effluents from municipal wastewater treatment plants. Heterotrophic bacteria, Escherichia coli, enterococci, Clostridium perfringens spores, somatic coliphages and eukaryotes (amoebae, flagellates, ciliates and metazoa) were tested as indicator microorganisms. EC with an Fe/Fe cell at 200 A m -2 and natural pH allowed >5 log unit removal of E. coli and final concentration below 1 bacteria mL -1 of coliphages and eukaryotes from both effluents in ca. 60 min, whereas heterotrophic bacteria, enterococci and spores were more resistant. A larger removal was obtained for the primary effluent, probably because the flocs remove higher amount of total organic carbon (TOC), entrapping more easily the microbiota. EF with a boron-doped diamond (BDD) anode and an air-diffusion cathode that produces H 2 O 2 on site was first performed at pH 3.0, with large or even total inactivation of microorganisms within 30 min. A more effective microorganism removal was attained as compared to EC thanks to • OH formed from Fenton's reaction. A quicker disinfection was observed for the secondary effluent owing to its lower TOC content, allowing the attack of greater quantities of electrogenerated oxidants on microorganisms. Wastewater disinfection by EF was also feasible at natural pH (∼7), showing similar abatement of active microorganisms as a result of the synergistic action of generated oxidants like active chlorine and coagulation with iron hydroxides. A sequential EC/EF treatment (30 min each) was more effective for a combined decontamination and disinfection of urban wastewater. Copyright © 2017 Elsevier Ltd. All rights reserved.

Endemic bacteriophages: a cautionary tale for evaluation of bacteriophage therapy and other interventions for infection control in animals

Directory of Open Access Journals (Sweden)

Kropinski Andrew M

2012-09-01

Full Text Available Abstract Background One of the most effective targets for control of zoonotic foodborne pathogens in the farm to fork continuum is their elimination in food animals destined for market. Phage therapy for Escherichia coli O157:H7 in ruminants, the main animal reservoir of this pathogen, is a popular research topic. Since phages active against this pathogen may be endemic in host animals and their environment, they may emerge during trials of phage therapy or other interventions, rendering interpretation of trials problematic. Methods During separate phage therapy trials, sheep and cattle inoculated with 109 to 1010 CFU of E. coli O157:H7 soon began shedding phages dissimilar in plaque morphology to the administered therapeutic phages. None of the former was previously identified in the animals or in their environment. The dissimilar “rogue” phage was isolated and characterized by host range, ultrastructure, and genomic and proteomic analyses. Results The “rogue” phage (Phage vB_EcoS_Rogue1 is distinctly different from the administered therapeutic Myoviridae phages, being a member of the Siphoviridae (head: 53 nm; striated tail: 152 x 8 nm. It has a 45.8 kb genome which is most closely related to coliphage JK06, a member of the “T1-like viruses” isolated in Israel. Detailed bioinformatic analysis reveals that the tail of these phages is related to the tail genes of coliphage lambda. The presence of “rogue” phages resulting from natural enrichments can pose problems in the interpretation of phage therapeutic studies. Similarly, evaluation of any interventions for foodborne or other bacterial pathogens in animals may be compromised unless tests for such phages are included to identify their presence and potential impact.

Long-term monitoring of waterborne pathogens and microbial source tracking markers in paired agricultural watersheds under controlled and conventional tile drainage management.

Science.gov (United States)

Wilkes, Graham; Brassard, Julie; Edge, Thomas A; Gannon, Victor; Gottschall, Natalie; Jokinen, Cassandra C; Jones, Tineke H; Khan, Izhar U H; Marti, Romain; Sunohara, Mark D; Topp, Edward; Lapen, David R

2014-06-01

Surface waters from paired agricultural watersheds under controlled tile drainage (CTD) and uncontrolled tile drainage (UCTD) were monitored over 7 years in order to determine if there was an effect of CTD (imposed during the growing season) on occurrences and loadings of bacterial and viral pathogens, coliphages, and microbial source tracking markers. There were significantly lower occurrences of human, ruminant, and livestock (ruminant plus pig) Bacteroidales markers in the CTD watershed in relation to the UCTD watershed. As for pathogens, there were significantly lower occurrences of Salmonella spp. and Arcobacter spp. in the CTD watershed. There were no instances where there were significantly higher quantitative loadings of any microbial target in the CTD watershed, except for F-specific DNA (F-DNA) and F-RNA coliphages, perhaps as a result of fecal inputs from a hobby farm independent of the drainage practice treatments. There was lower loading of the ruminant marker in the CTD watershed in relation to the UCTD system, and results were significant at the level P = 0.06. The odds of Salmonella spp. occurring increased when a ruminant marker was present relative to when the ruminant marker was absent, yet for Arcobacter spp., the odds of this pathogen occurring significantly decreased when a ruminant marker was present relative to when the ruminant marker was absent (but increased when a wildlife marker was present relative to when the wildlife marker was absent). Interestingly, the odds of norovirus GII (associated with human and swine) occurring in water increased significantly when a ruminant marker was present relative to when a ruminant marker was absent. Overall, this study suggests that fecal pollution from tile-drained fields to stream could be reduced by CTD utilization. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Development of multiple linear regression models as predictive tools for fecal indicator concentrations in a stretch of the lower Lahn River, Germany.

Science.gov (United States)

Herrig, Ilona M; Böer, Simone I; Brennholt, Nicole; Manz, Werner

2015-11-15

Since rivers are typically subject to rapid changes in microbiological water quality, tools are needed to allow timely water quality assessment. A promising approach is the application of predictive models. In our study, we developed multiple linear regression (MLR) models in order to predict the abundance of the fecal indicator organisms Escherichia coli (EC), intestinal enterococci (IE) and somatic coliphages (SC) in the Lahn River, Germany. The models were developed on the basis of an extensive set of environmental parameters collected during a 12-months monitoring period. Two models were developed for each type of indicator: 1) an extended model including the maximum number of variables significantly explaining variations in indicator abundance and 2) a simplified model reduced to the three most influential explanatory variables, thus obtaining a model which is less resource-intensive with regard to required data. Both approaches have the ability to model multiple sites within one river stretch. The three most important predictive variables in the optimized models for the bacterial indicators were NH4-N, turbidity and global solar irradiance, whereas chlorophyll a content, discharge and NH4-N were reliable model variables for somatic coliphages. Depending on indicator type, the extended mode models also included the additional variables rainfall, O2 content, pH and chlorophyll a. The extended mode models could explain 69% (EC), 74% (IE) and 72% (SC) of the observed variance in fecal indicator concentrations. The optimized models explained the observed variance in fecal indicator concentrations to 65% (EC), 70% (IE) and 68% (SC). Site-specific efficiencies ranged up to 82% (EC) and 81% (IE, SC). Our results suggest that MLR models are a promising tool for a timely water quality assessment in the Lahn area. Copyright © 2015 Elsevier Ltd. All rights reserved.

Inactivation of Viruses and Bacteriophages as Models for Swine Hepatitis E Virus in Food Matrices.

Science.gov (United States)

Emmoth, Eva; Rovira, Jordi; Rajkovic, Andreja; Corcuera, Elena; Wilches Pérez, Diego; Dergel, Irene; Ottoson, Jakob R; Widén, Frederik

2017-03-01

Hepatitis E virus has been recognised as a food-borne virus hazard in pork products, due to its zoonotic properties. This risk can be reduced by adequate treatment of the food to inactivate food-borne viruses. We used a spectrum of viruses and bacteriophages to evaluate the effect of three food treatments: high pressure processing (HPP), lactic acid (LA) and intense light pulse (ILP) treatments. On swine liver at 400 MPa for 10 min, HPP gave log 10 reductions of ≥4.2, ≥5.0 and 3.4 for feline calicivirus (FCV) 2280, FCV wildtype (wt) and murine norovirus 1 (MNV 1), respectively. Escherichia coli coliphage ϕX174 displayed a lower reduction of 1.1, while Escherichia coli coliphage MS2 was unaffected. For ham at 600 MPa, the corresponding reductions were 4.1, 4.4, 2.9, 1.7 and 1.3 log 10 . LA treatment at 2.2 M gave log 10 reductions in the viral spectrum of 0.29-2.1 for swine liver and 0.87-3.1 for ham, with ϕX174 and MNV 1, respectively, as the most stable microorganisms. The ILP treatment gave log 10 reductions of 1.6-2.8 for swine liver, 0.97-2.2 for ham and 1.3-2.3 for sausage, at 15-60 J cm -2 , with MS2 as the most stable microorganism. The HPP treatment gave significantly (p virus reduction on swine liver than ham for the viruses at equivalent pressure/time combinations. For ILP treatment, reductions on swine liver were significantly (p virus contamination and in advice to food producers. Conservative model indicators for the pathogenic viruses could be suggested.

Long-Term Monitoring of Waterborne Pathogens and Microbial Source Tracking Markers in Paired Agricultural Watersheds under Controlled and Conventional Tile Drainage Management

Science.gov (United States)

Wilkes, Graham; Brassard, Julie; Edge, Thomas A.; Gannon, Victor; Gottschall, Natalie; Jokinen, Cassandra C.; Jones, Tineke H.; Khan, Izhar U. H.; Marti, Romain; Sunohara, Mark D.; Topp, Edward

2014-01-01

Surface waters from paired agricultural watersheds under controlled tile drainage (CTD) and uncontrolled tile drainage (UCTD) were monitored over 7 years in order to determine if there was an effect of CTD (imposed during the growing season) on occurrences and loadings of bacterial and viral pathogens, coliphages, and microbial source tracking markers. There were significantly lower occurrences of human, ruminant, and livestock (ruminant plus pig) Bacteroidales markers in the CTD watershed in relation to the UCTD watershed. As for pathogens, there were significantly lower occurrences of Salmonella spp. and Arcobacter spp. in the CTD watershed. There were no instances where there were significantly higher quantitative loadings of any microbial target in the CTD watershed, except for F-specific DNA (F-DNA) and F-RNA coliphages, perhaps as a result of fecal inputs from a hobby farm independent of the drainage practice treatments. There was lower loading of the ruminant marker in the CTD watershed in relation to the UCTD system, and results were significant at the level P = 0.06. The odds of Salmonella spp. occurring increased when a ruminant marker was present relative to when the ruminant marker was absent, yet for Arcobacter spp., the odds of this pathogen occurring significantly decreased when a ruminant marker was present relative to when the ruminant marker was absent (but increased when a wildlife marker was present relative to when the wildlife marker was absent). Interestingly, the odds of norovirus GII (associated with human and swine) occurring in water increased significantly when a ruminant marker was present relative to when a ruminant marker was absent. Overall, this study suggests that fecal pollution from tile-drained fields to stream could be reduced by CTD utilization. PMID:24727274

Experimental justification of indicative microbiological values for the safety of water bodies in the recreation areas

Directory of Open Access Journals (Sweden)

Е.V. Drozdova

2015-03-01

Full Text Available The article provides the assessment of the microbiological values of water bodies if they are used for recreational purposes and distinguishes the epidemiologically significant parameters. In order to validate the indicative safety values taking into account the existing conditions of the recreational use of water we conducted the hygienic assessment of water in the water bodies used for recreational purposes under the indicative microbiological values (total microbial count, thermotolerant coliform bacteria, E. coli; enterococcus, spores of sulfite-reducing Clostridia; coliphages; Ps. aeruginosa and the content of pathogenic microorganisms; also the microbiological profile of water was identified. The obtained data will be used to improve the system for monitoring of water bodies in the recreation areas.

Water and Wastewater Disinfection with Peracetic Acid and UV Radiation and Using Advanced Oxidative Process PAA/UV

Directory of Open Access Journals (Sweden)

Jeanette Beber de Souza

2015-01-01

Full Text Available The individual methods of disinfection peracetic acid (PAA and UV radiation and combined process PAA/UV in water (synthetic and sanitary wastewater were employed to verify the individual and combined action of these advanced oxidative processes on the effectiveness of inactivation of microorganisms indicators of fecal contamination E. coli, total coliforms (in the case of sanitary wastewater, and coliphages (such as virus indicators. Under the experimental conditions investigated, doses of 2, 3, and 4 mg/L of PAA and contact time of 10 minutes and 60 and 90 s exposure to UV radiation, the results indicated that the combined method PAA/UV provided superior efficacy when compared to individual methods of disinfection.

Coliphages as fecal pollution and removal bacterial indicators in the drinking water process

OpenAIRE

Paz-y-Miño, Marco; Barzola, Carmen; Lazcano, César; Ponce, Milagros; León, Jorge

2003-01-01

El presente trabajo analiza la eficacia del tratamiento de agua procedentes del río Rímac. Se comparan muestras de agua no tratadas con las fases sucesivas del tratamiento: decantación, filtración y clorinación. La cuantificación de colifagos fue realizada por los métodos de Capa Simple y Filtro de Membrana. Los Coliformes Totales (CT), Coliformes Termotolerantes (CTT) y Bacterias Heterótrofas (BH) fueron determinados por los métodos del Número Más Probable (NMP) y Filtro de Membrana. La cepa...

Damage to the DNA of microorganisms from decay of incorporated 125I and the relationship of DNA damage to lethal effects

International Nuclear Information System (INIS)

Krisch, R.E.; Krasin, F.; Sauri, C.J.

1975-01-01

Iodine-125 decays by electron capture and is known to cause severe molecular damage to small organic molecules via vacancy cascades. In an examination of the biological effects of this decay mode we have labelled coliphages T1 and T4, as well as E. coli, with 125 I-5-iododeoxyuridine, which is incorporated into DNA in place of thymidine. Labelled organisms are generally stored in liquid nitrogen at -196 0 C during decay and are periodically assayed for loss of viability and for breakage of DNA, using neutral and alkaline sucrose gradient sedimentation techniques. Briefly, our experiments have demonstrated drastic damage to DNA from the decay of incorporated 125 I, as would be predicted from the data for small molecules. (auth)

Phage Pl mutants with altered transducing abilities for Escherichia coli

International Nuclear Information System (INIS)

Wall, J.D.; Harriman, P.D.

1974-01-01

A search was made for mutants of the coliphage P1 with altered transducing frequencies. A method was developed for the rapid assay of transducing frequencies in single plaques using prophage lambda as the transduced bacterial marker. This procedure selects for mutants altered in their ability to package host DNA. Mutants with 5 to 10 times higher or 10 to 20 times lower frequencies than those of wild-type P1 were found. Not only are the markers used for the detection of the mutants affected, but all other markers are similarly affected (not always to the same extent). One of the high transducing frequency mutants is a suppressible amber, indicating that loss of a function increases P1's ability to package host DNA preferentially. (U.S.)

Effect of the mixed liquor suspended solid on permeate in a membrane bioreactor system applied for the treatment of sewage mixed with wastewater of the milk from the dairy industry.

Science.gov (United States)

Poyatos, José M; Molina-Muñoz, Marisa; Moreno, Begoña; González-López, Jesús; Hontoria, Ernesto

2007-06-01

The performance of a bench-scale submerged membrane bioreactor (MBR) equipped with ultrafiltration membranes (ZENON) was investigated at different mixed liquor suspended solid (MLSS) concentrations (3069, 4314 and 6204 mg/L). The pilot plant was located in the wastewater treatment plant of the city of Granada (Puente de los Vados, Granada, Spain), which receives the wastewater of the milk from the dairy industry of Granada. The results showed the capacity of the MBR systems to remove organic material (COD and BOD5), suspended solids, turbidity, color and microbial indicators such as E. coli and coliphages. Therefore, the results suggest that the transmembrane pressure (TMP) was influence by the MLSS concentration assayed. However, an increase in the MLSS concentration increases the nitrification processes and consequently the amount of NO3- in permeate.

DNA Nucleotide Sequence Restricted by the RI Endonuclease

Science.gov (United States)

Hedgpeth, Joe; Goodman, Howard M.; Boyer, Herbert W.

1972-01-01

The sequence of DNA base pairs adjacent to the phosphodiester bonds cleaved by the RI restriction endonuclease in unmodified DNA from coliphage λ has been determined. The 5′-terminal nucleotide labeled with 32P and oligonucleotides up to the heptamer were analyzed from a pancreatic DNase digest. The following sequence of nucleotides adjacent to the RI break made in λ DNA was deduced from these data and from the 3′-dinucleotide sequence and nearest-neighbor analysis obtained from repair synthesis with the DNA polymerase of Rous sarcoma virus [Formula: see text] The RI endonuclease cleavage of the phosphodiester bonds (indicated by arrows) generates 5′-phosphoryls and short cohesive termini of four nucleotides, pApApTpT. The most striking feature of the sequence is its symmetry. PMID:4343974

Disinfection of wastewaters: high-energy electron vs gamma irradiation

Energy Technology Data Exchange (ETDEWEB)

Farooq, S [King Fahd Univ. of Petroleum and Minerals, Dhahran (Saudi Arabia). Dept. of Civil Engineering; Kurucz, C N; Waite, T D [Miami Univ., Coral Gables, FL (United States); Cooper, W J [Florida International Univ., Miami, FL (United States). Drinking Water Research Center

1993-07-01

A study was undertaken to examine the sensitivity of a wastewater population of coliphage, total coliforms and total flora present in raw sewage and secondary effluent after irradiating with similar doses delivered by a high-energy electron beam and [gamma]-radiation. The electron beam study was conducted on a large scale at the Virginia Key Wastewater Treatment Plant, Miami, Florida. The facility is equipped with a 1.5 MeV, 50 mA electron accelerator, with a wastewater flow rate of 8ls[sup -1]. Concurrent [gamma]-radiation studies were conducted at laboratory scale using a 5000 Ci, [sup 60]Co [gamma]-source. Three logs reduction of all three test organisms were observed at an electron beam dose of 500 krads, while at least four logs reduction were observed at the same dose utilizing the [gamma]'source. (Author).

Zoonotic Aspects of Hepatitis E Virus in Denmark

DEFF Research Database (Denmark)

Krog, Jesper Schak

circulating in minks for years. The virus did not seem to cause clinical disease in mink, however, this should be investigated further. Manuscript II describes the leaching of HEV along with rotavirus (RV), porcine circovirus type 2 (PCV2), somatic coliphages, E. coli and Enterococcus spp. through field soil...... reservoirs in connection with the untreated drainage runoff. Rotavirus was detected in deeper groundwater screen indicating the possibility of groundwater contamination of viruses originating from manure, posing a risk for the contamination of important drinking water reservoirs in Denmark. Manuscript III...... focuses on the viral contamination of mussels farmed in Denmark. The mussels was assayed for HEV and Rotavirus, known to occur in shellfish and cause disease. Furthermore, PCV2was also assayed as an indicator of porcine waste contamination. All samples analyzed were negative for HEV and RV, however...

Microbiological Water Quality in Relation to Water-Contact Recreation, Cuyahoga River, Cuyahoga Valley National Park, Ohio, 2000 and 2002

Science.gov (United States)

Bushon, Rebecca N.; Koltun, G.F.

2004-01-01

The microbiological water quality of a 23-mile segment of the Cuyahoga River within the Cuyahoga Valley National Park was examined in this study. This segment of the river receives discharges of contaminated water from stormwater, combined-sewer overflows, and incompletely disinfected wastewater. Frequent exceedances of Ohio microbiological water-quality standards result in a health risk to the public who use the river for water-contact recreation. Water samples were collected during the recreational season of May through October at four sites on the Cuyahoga River in 2000, at three sites on the river in 2002, and from the effluent of the Akron Water Pollution Control Station (WPCS) both years. The samples were collected over a similar range in streamflow in 2000 and 2002. Samples were analyzed for physical and chemical constituents, as well as the following microbiological indicators and pathogenic organisms: Escherichia coli (E. coli), Salmonella, F-specific and somatic coliphage, enterovirus, infectious enterovirus, hepatitis A virus, Clostridium perfringens (C. perfringens), Cryptosporidium, and Giardia. The relations of the microorganisms to each other and to selected water-quality measures were examined. All microorganisms analyzed for, except Cryptosporidium, were detected at least once at each sampling site. Concentrations of E. coli exceeded the Ohio primary-contact recreational standard (298 colonies per 100 milliliters) in approximately 87 percent of the river samples and generally were higher in the river samples than in the effluent samples. C. perfringens concentrations were positively and significantly correlated with E. coli concentrations in the river samples and generally were higher in the effluent samples than in the river samples. Several of the river samples that met the Ohio E. coli secondary-contact recreational standard (576 colonies per 100 milliliters) had detections of enterovirus, infectious enterovirus, hepatitis A virus, and

The application of bacteriophages as novel indicators of viral pathogens in wastewater treatment systems.

Science.gov (United States)

Dias, Edgard; Ebdon, James; Taylor, Huw

2018-02-01

Many wastewater treatment technologies have been shown to remove bacterial pathogens more effectively than viral pathogens and, in aquatic environments, levels of traditional faecal indicator bacteria (FIB) do not appear to correlate consistently with levels of human viral pathogens. There is, therefore, a need for novel viral indicators of faecal pollution and surrogates of viral pathogens, especially given the increasing importance of indirect and direct wastewater reuse. Potential candidates include bacteriophages (phages) and the study described here sought to elucidate the relationship between three groups of phages (somatic coliphages (SOMPH), F-RNA coliphages (F-RNAPH) and human-specific phages infecting B. fragilis (Bf124PH) - enumeration using double layer agar technique) and viral pathogens (human adenovirus (HuAdV) and norovirus (NoV) - enumeration using molecular methods) through full-scale municipal wastewater treatment processes. FIB (faecal coliforms (FC) and intestinal enterococci (ENT) - enumeration using membrane filtration) were also monitored. Samples were collected every fortnight, during a twelve-month period, at each stage of four full-scale wastewater treatment plants (WWTP) in southern England (two activated sludge (AS) and two trickling filter (TF) plants) (n = 360 samples). FIB and SOMPH were consistently found in all samples tested, whereas F-RNAPH, Bf124PH and HuAdV were less frequently detected, especially following AS treatment. The detection rate of NoV was low and consequently discussion of this group of viruses is limited. Concentrations of SOMPH and FIB were statistically higher (p value F-RNAPH, Bf124PH and HuAdV in raw wastewater. FIB were more effectively removed than phages in both systems. Removal rates of HuAdV were similar to those of phages at the secondary treatment stage of both systems. In TF systems, HuAdV were removed at the same rate as F-RNAPH, but at lower rates than SOMPH and Bf124PH. The findings suggest that

Inactivation of norovirus surrogates on surfaces and raspberries by steam-ultrasound treatment

DEFF Research Database (Denmark)

Schultz, Anna Charlotte; Uhrbrand, Katrine; Nørrung, Birgit

2012-01-01

of infectious virus and viral genomes were determined by plaque assay and reverse transcription-real time quantitative PCR (RT-qPCR), respectively. On plastic surfaces, an inactivation of >99.99% was obtained for both MS2 and FCV, corresponding to a 9.1-log and >4.8-log reduction after 1 or 3 s of treatment......) resulted in negligible reductions of viral genome titers of MS2, FCV, and MNV on plastic surfaces as well as of MS2 inoculated on raspberries. Steam-ultrasound treatment in its current format does not appear to be an appropriate method to achieve sufficient decontamination of NoV-contaminated raspberries...... treatment that combines pressurized steam and high-power ultrasound (steam-ultrasound) was assessed for its efficacy to inactivate human NoV surrogates: coliphage (MS2), feline calicivirus (FCV), and murine norovirus (MNV) inoculated on plastic surfaces and MS2 inoculated on fresh raspberries. The amounts...

Impact of the use of an alcohol-based hand sanitizer in the home on reduction in probability of infection by respiratory and enteric viruses.

Science.gov (United States)

Tamimi, A H; Maxwell, S; Edmonds, S L; Gerba, C P

2015-11-01

The goal of this study was to determine the reduction in risk of infection by viruses with the use of an alcohol-based hand sanitizer, used in addition to routine hand washing, in family members in households. A quantitative microbial risk model was used to determine the probability of infection from the concentration of virus on the hands. The model incorporated variation in hand size, frequency of touching orifices (nose, mouth, eyes), and percent transfer to the site of infection, as well as, dose-response for each virus. Data on the occurrence of virus on household members' hands from an intervention study using MS-2 coliphage was used to determine the reduction of viruses on the hands pre- and post-intervention. It was found that the risk of rhinovirus, rotavirus or norovirus infection after the intervention was reduced by 47-98% depending upon the initial concentration of virus on the hands.

The complete sequence of marine bacteriophage VpV262 infecting vibrio parahaemolyticus indicates that an ancestral component of a T7 viral supergroup is widespread in the marine environment

International Nuclear Information System (INIS)

Hardies, Stephen C.; Comeau, Andre M.; Serwer, Philip; Suttle, Curtis A.

2003-01-01

The 46,012-bp sequence of the marine bacteriophage VpV262 infecting the bacterium Vibrio parahaemolyticus is reported. The VpV262 sequence reveals that it is a distant relative of marine Roseophage SIO1, and an even more distant relative of coliphage T7. VpV262 and SIO1 appear to represent a widespread marine phage group that lacks an RNA polymerase gene and is ancestral to the T7-like phages. We propose that this group together with the T7-like phages be designated as the T7 supergroup. The ancestral head structure gene module for the T7 supergroup was reconstructed by using sensitive biased Psi-blast searches supplemented by statistical support derived from gene order. In the early and replicative segments, these phages have participated in extensive interchange with the viral gene pool. VpV262 carries a different replicative module than SIO1 and the T7-like phages

Oral T4-like phage cocktail application to healthy adult volunteers from Bangladesh

International Nuclear Information System (INIS)

Sarker, Shafiqul Alam; McCallin, Shawna; Barretto, Caroline; Berger, Bernard; Pittet, Anne-Cécile; Sultana, Shamima; Krause, Lutz; Huq, Sayeda; Bibiloni, Rodrigo; Bruttin, Anne; Reuteler, Gloria; Brüssow, Harald

2012-01-01

The genomic diversity of 99 T4-like coliphages was investigated by sequencing an equimolar mixture with Illumina technology and screening them against different databases for horizontal gene transfer and undesired genes. A 9-phage cocktail was given to 15 healthy adults from Bangladesh at a dose of 3×10 9 and 3×10 7 plaque-forming units and placebo respectively. Phages were detected in 64% of the stool samples when subjects were treated with higher titer phage, compared to 30% and 28% with lower-titer phage and placebo, respectively. No Escherichia coli was present in initial stool samples, and no amplification of phage was observed. One percent of the administered oral phage was recovered from the feces. No adverse events were observed by self-report, clinical examination, or from laboratory tests for liver, kidney, and hematology function. No impact of oral phage was seen on the fecal microbiota composition with respect to bacterial 16S rRNA from stool.

Oral T4-like phage cocktail application to healthy adult volunteers from Bangladesh

Energy Technology Data Exchange (ETDEWEB)

Sarker, Shafiqul Alam, E-mail: sasarker@icddrb.org [International Centre for Diarrhoeal Diseases Research, Bangladesh (icddr,b), 68 Shaheed Tajuddin Ahmed Sharani, Mohakhali, Dhaka 1212 (Bangladesh); McCallin, Shawna; Barretto, Caroline [Nestle Research Centre, Nestec Ltd., Vers-chez-les-Blanc, CH-1000 Lausanne 26 (Switzerland); Berger, Bernard, E-mail: bernard.berger@rdls.nestle.com [Nestle Research Centre, Nestec Ltd., Vers-chez-les-Blanc, CH-1000 Lausanne 26 (Switzerland); Pittet, Anne-Cecile [Nestle Research Centre, Nestec Ltd., Vers-chez-les-Blanc, CH-1000 Lausanne 26 (Switzerland); Sultana, Shamima, E-mail: shamima@icddrb.org [International Centre for Diarrhoeal Diseases Research, Bangladesh (icddr,b), 68 Shaheed Tajuddin Ahmed Sharani, Mohakhali, Dhaka 1212 (Bangladesh); Krause, Lutz, E-mail: ltz.krause@gmail.com [Nestle Research Centre, Nestec Ltd., Vers-chez-les-Blanc, CH-1000 Lausanne 26 (Switzerland); Huq, Sayeda, E-mail: sayeeda@mail.icddrb.org [International Centre for Diarrhoeal Diseases Research, Bangladesh (icddr,b), 68 Shaheed Tajuddin Ahmed Sharani, Mohakhali, Dhaka 1212 (Bangladesh); Bibiloni, Rodrigo, E-mail: Rodrigo.Bibiloni@agresearch.co.nz [Nestle Research Centre, Nestec Ltd., Vers-chez-les-Blanc, CH-1000 Lausanne 26 (Switzerland); Bruttin, Anne, E-mail: anne.bruttin@rdls.nestle.com [Nestle Research Centre, Nestec Ltd., Vers-chez-les-Blanc, CH-1000 Lausanne 26 (Switzerland); Reuteler, Gloria, E-mail: gloria.reuteler@rdls.nestle.com [Nestle Research Centre, Nestec Ltd., Vers-chez-les-Blanc, CH-1000 Lausanne 26 (Switzerland); Bruessow, Harald, E-mail: harald.bruessow@rdls.nestle.com [Nestle Research Centre, Nestec Ltd., Vers-chez-les-Blanc, CH-1000 Lausanne 26 (Switzerland)

2012-12-20

The genomic diversity of 99 T4-like coliphages was investigated by sequencing an equimolar mixture with Illumina technology and screening them against different databases for horizontal gene transfer and undesired genes. A 9-phage cocktail was given to 15 healthy adults from Bangladesh at a dose of 3 Multiplication-Sign 10{sup 9} and 3 Multiplication-Sign 10{sup 7} plaque-forming units and placebo respectively. Phages were detected in 64% of the stool samples when subjects were treated with higher titer phage, compared to 30% and 28% with lower-titer phage and placebo, respectively. No Escherichia coli was present in initial stool samples, and no amplification of phage was observed. One percent of the administered oral phage was recovered from the feces. No adverse events were observed by self-report, clinical examination, or from laboratory tests for liver, kidney, and hematology function. No impact of oral phage was seen on the fecal microbiota composition with respect to bacterial 16S rRNA from stool.

Occurrence of Pepper Mild Mottle Virus (PMMoV) in Groundwater from a Karst Aquifer System in the Yucatan Peninsula, Mexico.

Science.gov (United States)

Rosiles-González, Gabriela; Ávila-Torres, Gerardo; Moreno-Valenzuela, Oscar A; Acosta-González, Gilberto; Leal-Bautista, Rosa María; Grimaldo-Hernández, Cinthya D; Brown, Judith K; Chaidez-Quiroz, Cristóbal; Betancourt, Walter Q; Gerba, Charles P; Hernández-Zepeda, Cecilia

2017-12-01

The Yucatan Peninsula of Mexico hosts a karst aquifer system that is the only source of freshwater for the area; however, it is vulnerable to human-mediated contamination. Pepper mild mottle virus (PMMoV) is one of the most abundant RNA viruses associated with human feces, making it a viable indicator for tracking fecal pollution in aquatic environments, including groundwater. In this study, groundwater samples collected from a karst aquifer from fresh and brackish water locations were analyzed for fecal indicator bacteria, somatic and male F+ specific coliphages, and PMMoV during the rainy and dry seasons. Total coliform bacteria were detected at all sites, whereas Escherichia coli were found at relatively low levels water type (p > 0.05). Physicochemical and indicator bacteria were not correlated with PMMoV concentrations. The abundance and prevalence of PMMoV in the karst aquifer may reflect its environmental persistence and its potential as a fecal indicator in this karst aquifer system.

The genome and proteome of a virulent Escherichia coli O157:H7 bacteriophage closely resembling Salmonella phage Felix O1

Directory of Open Access Journals (Sweden)

Waddell Thomas E

2009-04-01

Full Text Available Abstract Based upon whole genome and proteome analysis, Escherichia coli O157:H7-specific bacteriophage (phage wV8 belongs to the new myoviral genus, "the Felix O1-like viruses" along with Salmonella phage Felix O1 and Erwinia amylovora phage φEa21-4. The genome characteristics of phage wV8 (size 88.49 kb, mol%G+C 38.9, 138 ORFs, 23 tRNAs are very similar to those of phage Felix O1 (86.16 kb, 39.0 mol%G+C, 131 ORFs and 22 tRNAs and, indeed most of the proteins have their closest homologs within Felix O1. Approximately one-half of the Escherichia coli O157:H7 mutants resistant to phage wV8 still serotype as O157:H7 indicating that this phage may recognize, like coliphage T4, two different surface receptors: lipopolysaccharide and, perhaps, an outer membrane protein.

Correlations between Microbial Indicators, Pathogens, and Environmental Factors in a Subtropical Estuary

Science.gov (United States)

Ortega, Cristina; Solo-Gabriele, Helena M.; Abdelzaher, Amir; Wright, Mary; Deng, Yang; Stark, Lillian M.

2009-01-01

The objective of this study was to evaluate whether indicator microbes and physical-chemical parameters were correlated with pathogens within a tidally influenced estuary. Measurements included the analysis of physical-chemical parameters (pH, salinity, temperature, and turbidity), measurements of bacterial indicators (enterococci, fecal coliform, E. coli, and total coliform), viral indicators (somatic and MS2 coliphage), viral pathogens (enterovirus by culture), and protozoan pathogens (Cryptosporidium and Giardia). All pathogen results were negative with the exception of one sample which tested positive for culturable reovirus (8.5 MPN/100 L).. Notable physical-chemical parameters for this sample included low salinity (<1 ppt) and high water temperature (31 °C). Indicator bacteria and indicator virus levels for this sample were within average values typically measured within the study site and were low in comparison with levels observed in other freshwater environments. Overall results suggest that high levels of bacterial and viral indicators were associated with low salinity sites. PMID:19464704

Three New Escherichia coli Phages from the Human Gut Show Promising Potential for Phage Therapy.

Directory of Open Access Journals (Sweden)

Marion Dalmasso

Full Text Available With the emergence of multi-drug resistant bacteria the use of bacteriophages (phages is gaining renewed interest as promising anti-microbial agents. The aim of this study was to isolate and characterize phages from human fecal samples. Three new coliphages, ɸAPCEc01, ɸAPCEc02 and ɸAPCEc03, were isolated. Their phenotypic and genomic characteristics, and lytic activity against biofilm, and in combination with ciprofloxacin, were investigated. All three phages reduced the growth of E. coli strain DPC6051 at multiplicity of infection (MOI between 10-3 and 105. A cocktail of all three phages completely inhibited the growth of E. coli. The phage cocktail also reduced biofilm formation and prevented the emergence of phage-resistant mutants which occurred with single phage. When combined with ciprofloxacin, phage alone or in cocktail inhibited the growth of E. coli and prevented the emergence of resistant mutants. These three new phages are promising biocontrol agents for E. coli infections.

Groundwater quality in wells in central rural Finland: a microbiological and radiochemical survey

International Nuclear Information System (INIS)

Korhonen, L.; Niskanen, M.; Heinonen-Tanski, H.; Martikainen, P.J.; Salonen, L.; Taipalinen, I.

1996-01-01

The microbiological, physicochemical, and radiochemical water quality from samples of 150 rural wells in Finland was analyzed. Organic matter exceeded 12 mg KMnO4 L(-1) in 63% and nitrate 25 mg NO3 L(-1) in 29% of the wells. NO3--concentrations were higher in wells with cattle. Fecal coliforms and fecal streptococci were found in 10-40%. There was no direct positive correlation between heterotrophic and indicator bacteria. Salmonella or Campylobacter were not detected. Human pathogen Listeria monocytogenes was isolated from two and Yersinia enterocolitica serotypes O5 or O6 from four waters not containing fecal coliforms. Thus, the predictive value of fecal coliforms to indicate these pathogens is poor. Coliphages were found in seven wells. Mean concentrations of radon and long-lived alpha-active radionuclides were lower and those of beta-emitting radionuclides higher than the mean concentrations measured from groundwater in Finland. Radionuclides from the Chernobyl fallout were not detected

Integration of an innovative biological treatment with physical or chemical disinfection for wastewater reuse

International Nuclear Information System (INIS)

De Sanctis, Marco; Del Moro, Guido; Levantesi, Caterina; Luprano, Maria Laura; Di Iaconi, Claudio

2016-01-01

In the present paper, the effectiveness of a Sequencing Batch Biofilter Granular Reactor (SBBGR) and its integration with different disinfection strategies (UV irradiation, peracetic acid) for producing an effluent suitable for agricultural use was evaluated. The plant treated raw domestic sewage, and its performances were evaluated in terms of the removal efficiency of a wide group of physical, chemical and microbiological parameters. The SBBGR resulted really efficient in removing suspended solids, COD and nitrogen with an average effluent concentration of 5, 32 and 10 mg/L, respectively. Lower removal efficiency was observed for phosphorus with an average concentration in the effluent of 3 mg/L. Plant effluent was also characterized by an average electrical conductivity and sodium adsorption ratio of 680 μS/cm and 2.9, respectively. Therefore, according to these gross parameters, the SBBGR effluent was conformed to the national standards required in Italy for agricultural reuse. Moreover, disinfection performances of the SBBGR was higher than that of conventional municipal wastewater treatment plants and met the quality criteria suggested by WHO (Escherichia coli < 1000 CFU/100 mL) for agricultural reuse. In particular, the biological treatment by SBBGR removed 3.8 ± 0.4 log units of Giardia lamblia, 2.8 ± 0.8 log units of E. coli, 2.5 ± 0.7 log units of total coliforms, 2.0 ± 0.3 log units of Clostridium perfringens, 2.0 ± 0.4 log units of Cryptosporidium parvum and 1.7 ± 0.7 log units of Somatic coliphages. The investigated disinfection processes (UV and peracetic acid) resulted very effective for total coliforms, E. coli and somatic coliphages. In particular, a UV radiation and peracetic acid doses of 40 mJ/cm"2 and 1 mg/L respectively reduced E. coli content in the effluent below the limit for agricultural reuse in Italy (10 CFU/100 mL). Conversely, they were both ineffective on C.perfringens spores. - Highlights: • SBBGR system showed high

Integration of an innovative biological treatment with physical or chemical disinfection for wastewater reuse

Energy Technology Data Exchange (ETDEWEB)

De Sanctis, Marco, E-mail: marco.desanctis@ba.irsa.cnr.it [Water Research Institute, CNR, Via F. De Blasio 5, 70123 Bari (Italy); Del Moro, Guido [Water Research Institute, CNR, Via F. De Blasio 5, 70123 Bari (Italy); Levantesi, Caterina; Luprano, Maria Laura [Water Research Institute, CNR, Via Salaria Km 29.600, 00015 Monterotondo, RM (Italy); Di Iaconi, Claudio [Water Research Institute, CNR, Via F. De Blasio 5, 70123 Bari (Italy)

2016-02-01

In the present paper, the effectiveness of a Sequencing Batch Biofilter Granular Reactor (SBBGR) and its integration with different disinfection strategies (UV irradiation, peracetic acid) for producing an effluent suitable for agricultural use was evaluated. The plant treated raw domestic sewage, and its performances were evaluated in terms of the removal efficiency of a wide group of physical, chemical and microbiological parameters. The SBBGR resulted really efficient in removing suspended solids, COD and nitrogen with an average effluent concentration of 5, 32 and 10 mg/L, respectively. Lower removal efficiency was observed for phosphorus with an average concentration in the effluent of 3 mg/L. Plant effluent was also characterized by an average electrical conductivity and sodium adsorption ratio of 680 μS/cm and 2.9, respectively. Therefore, according to these gross parameters, the SBBGR effluent was conformed to the national standards required in Italy for agricultural reuse. Moreover, disinfection performances of the SBBGR was higher than that of conventional municipal wastewater treatment plants and met the quality criteria suggested by WHO (Escherichia coli < 1000 CFU/100 mL) for agricultural reuse. In particular, the biological treatment by SBBGR removed 3.8 ± 0.4 log units of Giardia lamblia, 2.8 ± 0.8 log units of E. coli, 2.5 ± 0.7 log units of total coliforms, 2.0 ± 0.3 log units of Clostridium perfringens, 2.0 ± 0.4 log units of Cryptosporidium parvum and 1.7 ± 0.7 log units of Somatic coliphages. The investigated disinfection processes (UV and peracetic acid) resulted very effective for total coliforms, E. coli and somatic coliphages. In particular, a UV radiation and peracetic acid doses of 40 mJ/cm{sup 2} and 1 mg/L respectively reduced E. coli content in the effluent below the limit for agricultural reuse in Italy (10 CFU/100 mL). Conversely, they were both ineffective on C.perfringens spores. - Highlights: • SBBGR system showed high

Microcosms for evaluating microbial indicator persistence and mobilization in fluvial sediments during rainfall events.

Science.gov (United States)

Martín-Díaz, Julia; García-Aljaro, Cristina; Pascual-Benito, Míriam; Galofré, Belén; Blanch, Anicet R; Lucena, Francisco

2017-10-15

Mediterranean rivers, which are subject to long, dry periods and heavy rainfall events, could be particularly useful for understanding future climate scenarios. This study generated microcosms that mimicked riverbank sediment resuspension into the water of a typical Mediterranean river as a consequence of heavy rainfall. The mobilization and inactivation of six fecal pollution indicators and microbial source tracking markers were evaluated. The T 90 values in the sediments were: 4 days for sorbitol-fermenting Bifidobacterium, 11 days for culturable E. coli, 36 days for bacteriophages infecting Bacteroides thetaiotaomicron strain GA17 and more than 42 days for qPCR-detected E. coli, somatic coliphages and sulfite-reducing clostridia spores. Bacteriophages and bacteria showed different resuspension and sedimentation patterns. The data obtained could be used in predictive models to assess the effects of climate change on surface water quality. Pathogen mobilization into the water column poses a risk for humans, animals and the natural environment, and breaches the One Health approach. Copyright © 2017 Elsevier Ltd. All rights reserved.

Process performance assessment of advanced anaerobic digestion of sewage sludge including sequential ultrasound-thermal (55 °C) pre-treatment.

Science.gov (United States)

Neumann, Patricio; Barriga, Felipe; Álvarez, Claudia; González, Zenón; Vidal, Gladys

2018-03-15

The aim of this study was to evaluate the performance and digestate quality of advanced anaerobic digestion of sewage sludge including sequential ultrasound-thermal (55 °C) pre-treatment. Both stages of pre-treatment contributed to chemical oxygen demand (COD) solubilization, with an overall factor of 11.4 ± 2.2%. Pre-treatment led to 19.1, 24.0 and 29.9% increased methane yields at 30, 15 and 7.5 days solid retention times (SRT), respectively, without affecting process stability or accumulation of intermediates. Pre-treatment decreased up to 4.2% water recovery from the digestate, but SRT was a more relevant factor controlling dewatering. Advanced digestion showed 2.4-3.1 and 1.5 logarithmic removals of coliforms and coliphages, respectively, and up to a 58% increase in the concentration of inorganics in the digestate solids compared to conventional digestion. The COD balance of the process showed that the observed increase in methane production was proportional to the pre-treatment solubilization efficiency. Copyright © 2018 Elsevier Ltd. All rights reserved.

Family values in the age of genomics: comparative analyses of temperate bacteriophage HK022.

Science.gov (United States)

Weisberg, R A; Gottesmann, M E; Hendrix, R W; Little, J W

1999-01-01

HK022 is a temperate coliphage related to phage lambda. Its chromosome has been completely sequenced, and several aspects of its life cycle have been intensively studied. In the overall arrangement, expression, and function of most of its genes, HK022 broadly resembles lambda and other members of the lambda family. Upon closer view, significant differences emerge. The differences reveal alternative strategies used by related phages to cope with similar problems and illuminate previously unknown regulatory and structural motifs. HK022 prophages protect lysogens from superinfection by producing a sequence-specific RNA binding protein that prematurely terminates nascent transcripts of infecting phage. It uses a novel RNA-based mechanism to antiterminate its own early transcription. The HK022 protein shell is strengthened by a complex pattern of covalent subunit interlinking to form a unitary structure that resembles chain-mail armour. Its integrase and repressor proteins are similar to those of lambda, but the differences provide insights into the evolution of biological specificity and the elements needed for construction of a stable genetic switch.

Natural attenuation in a surface water channel and a coastal aquifer by monitoring presence and removal of indicator bacteria, pathogens and antibiotic resistance gene: model development

Science.gov (United States)

Masciopinto, Costantino; Visino, Fabrizio; Luprano, Maria Laura; Levantesi, Caterina; Tandoi, Valter

2015-04-01

The spreading of microbial contamination into the environment, represents a very relevant problem, which leads to an increasing health concern. For this reason, it is important to identify and characterize the extent of natural depuration in water environmental particularly for reducing the presence of faecal contamination indicator bacteria, pathogens and antibiotic resistance genes (ARG). In this study, the presence of the above reported microbial parameters was analyzed in a surface water channel and in a coastal aquifer in southern Italy (Ostuni) southern Italy, both affected by Ostuni municipal treatment plant effluents and by local run-off. Several samples were collected from surface water, flowing in channels, and from wells in our study area. In particular, the water samples were analyzed to detect 7 fecal contamination indicators (E. coli, total coliforms, Clostridium p. spores, somatic coliphages, Enterococci and heterotrophic bacteria), Salmonella spp and the presence of ARGs. The water samples were also tested for chemical constituents. Finally a mathematical model has been developed in order to simulate pathogen migration pathways in the fractured groundwater and corresponding possible mitigation of pathogens in pumping wells.

ALTERNATIVE MICROBIAL INDICATORS OF FAECAL POLLUTION: CURRENT PERSPECTIVE

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V. K. Tyagi, A. K. Chopra, A. A. Kazmi, Arvind Kumar

2006-07-01

Full Text Available Worldwide coliform bacteria are used as indicators of fecal contamination and hence, the possible presence of disease causing organisms. Therefore, it is important to understand the potential and limitations of these indicator organisms before realistically implementing guidelines and regulations to safeguard our water resources and public health. This review addresses the limitations of current faecal indicator microorganisms and proposed significant alternative microbial indicators of water and wastewater quality. The relevant literature brings out four such significant microbial water pollution indicators and the study of these indicators will reveal the total spectrum of water borne pathogens. As E.coli and enterococci indicates the presence of bacterial pathogens, Coliphages indicate the presence of enteric viruses, and Clostridium perfringens, an obligate anaerobe, indicates presence of parasitic protozoan and enteric viruses. Therefore, monitoring a suite of indicator organisms in reclaimed effluent is more likely to be predictive of the presence of certain pathogens in order to protect public health, as no single indicator is most highly predictive of membership in the presence or absence category for pathogens.

Characterization of ionizing radiation damage in DNA. Progress report, May 1, 1974--April 30, 1975

International Nuclear Information System (INIS)

Hawkins, R.B.

1975-01-01

The objective of this research is the characterization and quantitative assay of ionizing radiation induced damage in DNA and nucleoprotein. Two lines of investigation have been pursued. The first is aimed at detection and assay of the amount of DNA to protein covalent cross linkage in coliphage T7. Protein and DNA are labeled with 14 C and 32 P, respectively. Cross linkage is assessed from the amount of labeled protein remaining with DNA after efforts to separate the two components by countercurrent distribution in a phenol-water system. It has been found that cross linkage occurs in phage irradiated with cobalt 60 gamma radiation while in dilute neutral aqueous solutions of phosphate buffer and phosphate buffer plus 1-histidine. Cross linkage is largely due to indirect effects and accompanied by protein and DNA fragmentation. The second line of investigation is a study of the hydrodynamic and viscoelastic properties of dilute solution of DNA from irradiated bacteriophage and cells. A device for this purpose, which will measure the elastic retardation time of DNA solutions, is being constructed. (U.S.)

Genomic sequences of two novel Levivirus single-stranded RNA coliphages (family Leviviridae): Evidence for recombination in environmental strains

Science.gov (United States)

Bacteriophages are likely the most abundant entities in the aquatic environment, yet knowledge of their ecology is limited. During a fecal source-tracking study, two genetically novel Leviviridae strains were discovered. Although the novel strains were isolated from coastal wat...

Inactivation of Adenovirus Type 5, Rotavirus WA and Male Specific Coliphage (MS2 in Biosolids by Lime Stabilization

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Aaron B. Margolin

2007-03-01

Full Text Available The use of lime to reduce or eliminate pathogen content is a cost-effective treatment currently employed in many Class B biosolids production plants in the United States. A bench scale model of lime stabilization was designed to evaluate the survival of adenovirus type 5, rotavirus Wa, and the male specific bacteriophage, MS2, in various matrices. Each virus was initially evaluated independently in a reverse osmosis treated water matrix limed with an aqueous solution of calcium hydroxide for 24-hr at 22 ± 5°C. In all R/O water trials, adenovirus type 5, rotavirus Wa and MS2 were below detectable levels (<100.5 TCID50/mL and <1 PFU/mL respectively following 0.1-hr of liming. Adenovirus type 5, rotavirus Wa, and MS2, were inoculated into composted, raw and previously limed matrices, representative of sludge and biosolids, to achieve a final concentration of approximately 104 PFU or TCID50/mL. Each matrix was limed for 24-hr at 22 ± 5°C and 4 ± 2°C. In all trials virus was below detectable levels following a 24-hr incubation. The time required for viral inactivation varied depending on the temperature and sample matrix. This research demonstrates reduction of adenovirus type 5, rotavirus Wa, and male-specific bacteriophage, in water, sludge and biosolids matrices following addition of an 8% calcium hydroxide slurry to achieve a pH of 12 for 2-hr reduced to 11.5 for 22-hr by addition of 0.1 N HCl. In these trials, MS2 was a conservative indicator of the efficacy of lime stabilization of adenovirus Type 5 and rotavirus Wa and therefore is proposed as a useful indicator organism.

Aberrant regulation of synthesis and degradation of viral proteins in coliphage lambda-infected UV-irradiated cells and in minicells

International Nuclear Information System (INIS)

Shaw, J.E.; Epp, C.; Pearson, M.L.; Reeve, J.N.

1987-01-01

The patterns of bacteriophage lambda proteins synthesized in UV-irradiated Escherichia coli cells and in anucleate minicells are significantly different; both systems exhibit aberrations of regulation in lambda gene expression. In unirradiated cells or cells irradiated with low UV doses (less than 600 J/m2), regulation of lambda protein synthesis is controlled by the regulatory proteins CI, N, CII, CIII, Cro, and Q. As the UV dose increases, activation of transcription of the cI, rexA, and int genes by CII and CIII proteins fails to occur and early protein synthesis, normally inhibited by the action of Cro, continues. After high UV doses (greater than 2000 J/m2), late lambda protein synthesis does not occur. Progression through the sequence of regulatory steps in lambda gene expression is slower in infected minicells. In minicells, there is no detectable cII- and cIII-dependent synthesis of CI, RexA, or Int proteins and inhibition of early protein synthesis by Cro activity is always incomplete. The synthesis of early b region proteins is not subject to control by CI, N, or Cro proteins, and evidence is presented suggesting that, in minicells, transcription of the early b region is initiated at a promoter(s) within the b region. Proteolytic cleavage of the regulatory proteins O and N and of the capsid proteins C, B, and Nu3 is much reduced in infected minicells. Exposure of minicells to very high UV doses before infection does not completely inhibit late lambda protein synthesis

Assessment and impact of microbial fecal pollution and human enteric pathogens in a coastal community.

Science.gov (United States)

Lipp, E K; Farrah, S A; Rose, J B

2001-04-01

The goals of this study were to assess watersheds impacted by high densities of OSDS (onsite sewage disposal systems) for evidence of fecal contamination and evaluate the occurrence of human pathogens in coastal waters off west Florida. Eleven stations (representing six watersheds) were intensively sampled for microbial indicators of fecal pollution (fecal coliform bacteria, enterococci, Clostridium perfringens and coliphage) and the human enteric pathogens, Cryptosporidium, Giardia, and enteroviruses during the summer rainy season (May-September 1996). Levels of all indicators ranged between 4000 CFU/100 ml. Cryptosporidium and Giardia were detected infrequently (6.8% and 2.3% of samples tested positive, respectively). Conversely, infectious enteroviruses were detected at low levels in 5 of the 6 watersheds sampled. Using cluster analysis, sites were grouped into two categories, high and low risks, based on combined levels of indicators. These results suggest that stations of highest pollution risk were located within areas of high OSDS densities. Furthermore, data indicate a subsurface transport of contaminated water to surface waters. The high prevalence of enteroviruses throughout the study area suggests a chronic pollution problem and potential risk to recreational swimmers in and around Sarasota Bay.

Characterization of ionizing radiation damage in DNA. Progress report, May 1, 1975--April 30, 1976

International Nuclear Information System (INIS)

Hawkins, R.B.

1976-01-01

The objective of this research is the characterization and quantitative assay of ionizing radiation-induced damage in DNA and nucleoprotein. Two lines of investigation have been pursued. The first is aimed at detection and assay of DNA to protein covalent cross linkage in coliphage T7. Protein and DNA are labeled with 14 C and 32 P, respectively. Cross linkage is assessed from the amount of labeled protein distributing like DNA and labeled DNA distributing like protein on a phenol-water countercurrent distribution system. It has been found that damage involving cross linkage occurs by two modes of radiation action in phage irradiated with 60 Co γ rays in .001M histidine medium. Indirect effects play a large role in one mode and direct effects play a large role in the other. In the second line of investigation, the hydrodynamic and viscoelastic properties of DNA from irradiated phage and cells will be examined to determine the extent to which DNA to DNA cross linkage and points of altered flexibility are introduced by radiation. An instrument for viscoelastic measurements has been constructed in preparation for these studies

Endogenous System Microbes as Treatment Process ...

Science.gov (United States)

Monitoring the efficacy of treatment strategies to remove pathogens in decentralized systems remains a challenge. Evaluating log reduction targets by measuring pathogen levels is hampered by their sporadic and low occurrence rates. Fecal indicator bacteria are used in centralized systems to indicate the presence of fecal pathogens, but are ineffective decentralized treatment process indicators as they generally occur at levels too low to assess log reduction targets. System challenge testing by spiking with high loads of fecal indicator organisms, like MS2 coliphage, has limitations, especially for large systems. Microbes that are endogenous to the decentralized system, occur in high abundances and mimic removal rates of bacterial, viral and/or parasitic protozoan pathogens during treatment could serve as alternative treatment process indicators to verify log reduction targets. To identify abundant microbes in wastewater, the bacterial and viral communities were examined using deep sequencing. Building infrastructure-associated bacteria, like Zoogloea, were observed as dominant members of the bacterial community in graywater. In blackwater, bacteriophage of the order Caudovirales constituted the majority of contiguous sequences from the viral community. This study identifies candidate treatment process indicators in decentralized systems that could be used to verify log removal during treatment. The association of the presence of treatment process indic

Changes of the Specific Infectivity of Tracer Phages during Transport in Porous Media.

Science.gov (United States)

Ghanem, Nawras; Trost, Manuel; Sánchez Fontanet, Laura; Harms, Hauke; Chatzinotas, Antonis; Wick, Lukas Y

2018-03-20

Phages (i.e., viruses infecting bacteria) are considered to be good indicators and tracers for fecal pollution, hydraulic flow, or colloidal transport in the subsurface. They are typically quantified as total virus particles (VLP) or plaque forming units (PFU) of infectious phages. As transport may lead to phage deactivation, VLP quantification can overestimate the number of infectious phages. In contrast, PFU counts may underestimate the transport of total virus particles. Using PFU and tunable resistive pulse sensing-based counting for active and total phages, respectively, we quantified the effect of transport through laboratory percolation columns on the specific infectivity (SI). The SI is defined by the ratio of total VLP to PFU and is a measure for the minimum particle numbers needed to create a single infection. Transport of three marine tracer phages and the coli-phage (T4) was described by colloidal filtration theory. We found that apparent collision efficiencies of active and total phages differed. Depending on the phage properties (e.g., morphology or hydrophobicity), passage through a porous medium led to either an increasing or decreasing SI of effluent phages. Our data suggest that both phage mass recovery and the SI should be considered in quantitative phage tracer experiments.

Cloning and characterization of the c1 repressor of Pseudomonas aeruginosa bacteriophage D3: a functional analog of phage lambda cI protein

Energy Technology Data Exchange (ETDEWEB)

Miller, R.V.; Kokjohn, T.A.

1987-05-01

We cloned the gene (c1) which encodes the repressor of vegetative function of Pseudomonas aeruginosa bacteriophage D3. The cloned gene was shown to inhibit plating of D3 and the induction of D3 lysogens by UV irradiation. The efficiency of plating and prophage induction of the heteroimmune P. aeruginosa phage F116L were not affected by the presence of the cloned c1 gene of D3. When the D3 DNA fragment containing c1 was subcloned into pBR322 and introduced into Escherichia coli, it was shown to specifically inhibit the plating of phage lambda and the induction of the lambda prophage by mitomycin C. The plating of lambda imm434 phage was not affected. Analysis in minicells indicated that these effects correspond to the presence of a plasmid-encoded protein of 36,000 molecular weight. These data suggest the possibility that coliphage lambda and the P. aeruginosa phage D3 evolved from a common ancestor. The conservation of the functional similarities of their repressors may have occurred because of the advantage to these temperate phages of capitalizing on the potential of the evolutionarily conserved RecA protein to monitor the level of damage to the host genome.

COMPORTAMIENTO DE LOS INDICADORES DE CONTAMINACIÓN FECAL EN DIFERENTE TIPO DE AGUAS DE LA SABANA DE BOGOTÁ (COLOMBIA

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Claudia Campos-Pinilla

2008-09-01

Full Text Available The world’s population is growing at such rate that not only the demands for water supply have raised considerably butalso its contamination levels. Residues from domestic and industrial origin have generated environmental problems andpublic health issues. Water contamination coming from domestic origin, shows a higher risk because of the quantity oforganic matter and the presence of pathogenic microorganisms. Due to determinations of these pathogens requiressophisticated laboratories and the techniques used for their detection are very costly and time consuming, it is proposedan alternative technique using bacteria, virus and parasites as faecal indicators, since they exhibit similar behaviour, andtheir determination techniques are a lot simpler, faster and low cost. The objective of the present study is to evaluate theoccurrence, concentration and behaviour of indicators from bacterial origin as faecal coliforms, from viral origin assomatic coliphages and F-specific RNA bacteriophages, and from parasite origin such as helminth eggs, Giardia cystsand Cryptosporidium oocysts. A series of samples were taken at surface, groundwater, drinking water and wastewatertreatment system in the surrounding area of Bogotá (Colombia. The results show the presence of all microbial indicatorsin all water samples, in similar concentrations to those found in different countries with different environments.

Restriction of phage T4 internal protein I mutants by a strain of Escherichia coli

International Nuclear Information System (INIS)

Black, L.W.; Abremski, K.

1974-01-01

Phage T4 internal protein I(IPI), a small (ca, 10,000 MW), basic protein injected into the host with the phage DNA, is not required for infection of most hosts, but mutants defective in IPI are restricted by at least one naturally occurring strain of Escherichia coli, CT 596 (CT). Phages lacking IPI (IPI - ) appear to inject their DNA and bind it to the membrane of CT cells as well as wild-type phage T4 does, but shutoff of host protein synthesis, initiation of T4 protein synthesis, and cell killing are abnormal in the IPI - mutant infected CT host. The injection of IPI appears to be important in allowing T4 DNA to carry out early steps involved in takeover of this host. Restriction of IPI - phage growth by CT cells appears to be due, at least in part, to a defective prophage it harbors which renders the host resistant to successful infection by phage T4 which lack IPI or rII functions. Bacteria cured of this prophage can be infected by mutants defective in these functions. The resistance of CT cells to other coliphages, and the question of T-even phage internal protein diversity are discussed. (U.S.)

Cloning and characterization of the c1 repressor of Pseudomonas aeruginosa bacteriophage D3: a functional analog of phage lambda cI protein

International Nuclear Information System (INIS)

Miller, R.V.; Kokjohn, T.A.

1987-01-01

We cloned the gene (c1) which encodes the repressor of vegetative function of Pseudomonas aeruginosa bacteriophage D3. The cloned gene was shown to inhibit plating of D3 and the induction of D3 lysogens by UV irradiation. The efficiency of plating and prophage induction of the heteroimmune P. aeruginosa phage F116L were not affected by the presence of the cloned c1 gene of D3. When the D3 DNA fragment containing c1 was subcloned into pBR322 and introduced into Escherichia coli, it was shown to specifically inhibit the plating of phage lambda and the induction of the lambda prophage by mitomycin C. The plating of lambda imm434 phage was not affected. Analysis in minicells indicated that these effects correspond to the presence of a plasmid-encoded protein of 36,000 molecular weight. These data suggest the possibility that coliphage lambda and the P. aeruginosa phage D3 evolved from a common ancestor. The conservation of the functional similarities of their repressors may have occurred because of the advantage to these temperate phages of capitalizing on the potential of the evolutionarily conserved RecA protein to monitor the level of damage to the host genome

Novel N4 Bacteriophages Prevail in the Cold Biosphere.

Science.gov (United States)

Zhan, Yuanchao; Buchan, Alison; Chen, Feng

2015-08-01

Coliphage N4 is a lytic bacteriophage discovered nearly half a century ago, and it was considered to be a "genetic orphan" until very recently, when several additional N4-like phages were discovered to infect nonenteric bacterial hosts. Interest in this genus of phages is stimulated by their unique genetic features and propagation strategies. To better understand the ecology of N4-like phages, we investigated the diversity and geographic patterns of N4-like phages by examining 56 Chesapeake Bay viral communities, using a PCR-clone library approach targeting a diagnostic N4-like DNA polymerase gene. Many new lineages of N4-like phages were found in the bay, and their genotypes shift from the lower to the upper bay. Interestingly, signature sequences of N4-like phages were recovered only from winter month samples, when water temperatures were below 4°C. An analysis of existing metagenomic libraries from various aquatic environments supports the hypothesis that N4-like phages are most prolific in colder waters. In particular, a high number of N4-like phages were detected in Organic Lake, Antarctica, a cold and hypersaline system. The prevalence of N4-like phages in the cold biosphere suggests these viruses possess yet-to-be-determined mechanisms that facilitate lytic infections under cold conditions. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Biological effects of ionizing radiation at the molecular, cellular, and organismal levels. Progress report, October 15, 1978-October 14, 1981

International Nuclear Information System (INIS)

Lange, C.S.

1981-06-01

Two major accomplishments have been achieved in the past three years with the support of this contract. Firstly, the original Zimm theory of rotor speed dependent DNA sedimentation has been tested quantitatively and found to be correct, i.e., T4c and T4D+ DNAs sedimented with S 0 20 /sub w/ values as predicted by the equation of Zimm and Schumaker. Furthermore, the quantitative validity of the theory means that the size (M/sub r/) of a DNA sedimenting under speed-dependent conditions is not undefinable but rather can be uniquely obtained by the application of that theory to the data. Secondly, the viscoelastic recoil (GAMMA 11 ), or more accurately, the zero shear rate reduced recoil (GAMMA 11 /sub r,O/) has been shown to be a quantitative direct function of the number of intact (T4c) DNA molecules present (per ml) in solution. This demonstration made possible the measurement of a direct survival curve for intact DNA molecules (i.e., without double-strand breaks) after exposure to ionizing radiation. A/sub DNA/D 37 of 47.4 krads was obtained for the DNA of T4c coliphage irradiated in air as a solution of phage particles. It is noteworthy that this survival curve measures the number of intact DNA molecules, not the average number of breaks/molecule

Biological effects of ionizing radiation at the molecular, cellular, and organismal levels. Triennial progress report, October 15, 1977-October 14, 1980

International Nuclear Information System (INIS)

Lange, C.S.

1980-01-01

Two major accomplishments have been achieved in the past three years with the support of this contract. Firstly, the original Zimm theory of rotor speed dependent DNA sedimentation has been tested quantitatively and found to be correct, i.e., T4c and T4D+ DNAs sedimented with S 0 /sub 20,w/ values as predicted by the equation of Zimm and Schumaker. Furthermore, the quantitative validity of the theory means that the size (M/sub r/) of a DNA sedimenting under speed-dependent conditions is not undefinable but rather can be uniquely obtained by the application of that theory to the data. Secondly, the viscoelastic recoil (GAMMA 11 ), or more accurately, the zero shear rate reduced recoil (GAMMA/sub 11, r, o/) has been shown to be a quantitative direct function of the number of intact (T4c) DNA molecules present (per ml) in solution. This demonstration made possible the measurement of a direct survival curve for intact DNA molecules (i.e., without double-strand breaks) after exposure to ionizing radiation. A /sub DNA/D 37 of 47.4 krads was obtained for the DNA of T4c coliphage irradiated in air as a solution of phage particles. It is noteworthy that this survival curve measures the number of intact DNA molecules, not the average number of breaks/molecule

Transfer Efficiency of Bacteria and Viruses from Porous and Nonporous Fomites to Fingers under Different Relative Humidity Conditions

Science.gov (United States)

Gerba, Charles P.; Tamimi, Akrum H.; Kitajima, Masaaki; Maxwell, Sheri L.; Rose, Joan B.

2013-01-01

Fomites can serve as routes of transmission for both enteric and respiratory pathogens. The present study examined the effect of low and high relative humidity on fomite-to-finger transfer efficiency of five model organisms from several common inanimate surfaces (fomites). Nine fomites representing porous and nonporous surfaces of different compositions were studied. Escherichia coli, Staphylococcus aureus, Bacillus thuringiensis, MS2 coliphage, and poliovirus 1 were placed on fomites in 10-μl drops and allowed to dry for 30 min under low (15% to 32%) or high (40% to 65%) relative humidity. Fomite-to-finger transfers were performed using 1.0 kg/cm2 of pressure for 10 s. Transfer efficiencies were greater under high relative humidity for both porous and nonporous surfaces. Most organisms on average had greater transfer efficiencies under high relative humidity than under low relative humidity. Nonporous surfaces had a greater transfer efficiency (up to 57%) than porous surfaces (humidity, as well as under high relative humidity (nonporous, up to 79.5%; porous, <13.4%). Transfer efficiency also varied with fomite material and organism type. The data generated can be used in quantitative microbial risk assessment models to assess the risk of infection from fomite-transmitted human pathogens and the relative levels of exposure to different types of fomites and microorganisms. PMID:23851098

Characterization of some pneumococcal bacteriophages

International Nuclear Information System (INIS)

Porter, R.D.; Guild, W.R.

1976-01-01

The growth of pneumococcal phages at high cell and phage densities is enhanced strongly by the substitution of potassium for sodium in the medium. Initial titers of 2 x 10 10 to 4 x 10 10 PFU/ml are readily obtained, and concentrated stocks are stable in a storage buffer described here. The mechanism of the cation effect is obscure. Phages ω3 and ω8 each have linear double-stranded DNA of 33 x 10 6 daltons per particle, with an apparent guanine plus cytosine content of 47 to 49 mol percent, as determined by buoyancy and melting temperature, but with an unusual absorbance spectrum. Efficiency of plating is high if sufficient time is allowed for a relatively slow adsorption, which differs several-fold in rate between the two phages. Morphologically, these and other pneumococcal phages are similar to coliphage lambda but with a longer tail and tail fiber. Upon UV inactivation, ω3 and ω8 have D 37 values of 33 and 55 J/m 2 , respectively, and each shows multiplicity reactivation. A total of 13 ts mutants have been isolated from the two phages, representing only two complementation groups; complementation and recombination occur between ω3 and ω8 mutants. Both phages provoke high-titer antisera with extensive cross-reactivity against a number of newly isolated pneumococcal phages

Fecal pollution source tracking toolbox for identification, evaluation and characterization of fecal contamination in receiving urban surface waters and groundwater.

Science.gov (United States)

Tran, Ngoc Han; Gin, Karina Yew-Hoong; Ngo, Huu Hao

2015-12-15

The quality of surface waters/groundwater of a geographical region can be affected by anthropogenic activities, land use patterns and fecal pollution sources from humans and animals. Therefore, the development of an efficient fecal pollution source tracking toolbox for identifying the origin of the fecal pollution sources in surface waters/groundwater is especially helpful for improving management efforts and remediation actions of water resources in a more cost-effective and efficient manner. This review summarizes the updated knowledge on the use of fecal pollution source tracking markers for detecting, evaluating and characterizing fecal pollution sources in receiving surface waters and groundwater. The suitability of using chemical markers (i.e. fecal sterols, fluorescent whitening agents, pharmaceuticals and personal care products, and artificial sweeteners) and/or microbial markers (e.g. F+RNA coliphages, enteric viruses, and host-specific anaerobic bacterial 16S rDNA genetic markers) for tracking fecal pollution sources in receiving water bodies is discussed. In addition, this review also provides a comprehensive approach, which is based on the detection ratios (DR), detection frequencies (DF), and fate of potential microbial and chemical markers. DR and DF are considered as the key criteria for selecting appropriate markers for identifying and evaluating the impacts of fecal contamination in surface waters/groundwater. Copyright © 2015 Elsevier B.V. All rights reserved.

Potential effect of some environmental factors on the phage removal during wastewater treatment. Study in vitro

International Nuclear Information System (INIS)

Benhyahya, M.; Bohatier, J.; Laveran, H.; Ettayebi, M.; Senaud, J.

2000-01-01

Great quantities of enteric viruses and bacteriophages are included in wastewaters. They represent a contamination risk of natural water systems. But this viral burden is greatly reduced in the sewage treatment plants by the combined action of numerous environmental factors. To study water quality, some groups of bacteriophages as E. coli phages and Bacteroides fragilis phages have been proposed as model viruses. On an other hand, somatic and, in particular, F-specific coliphages have several morphological, structural and chemical composition ressemblances with the enteric viruses. Two different bacteriophages (øX-174 and MS2) were used as virus models in this in vitro study to evaluate the viral adsorption on suspended clay particles. Distilled sterile water was used as reactional medium to avoid the possible interactions with the considered substrates, the kaolinite (K) and the montmorillonite (M). Phage behaviour in the water and in the recommended diluent for phages, the saline peptone, was first compared. K and M suspensions were used at 300 mg/l for a contact time of 5, 30 and 60 min. In other series K and M suspensions were prepared at 600, 300 and 100 mg/l then used to determine the phage adsorption capacity in a fixed time 30 min. Results show that the phage titers for all samples were constant in the organic diluent. They were lower in the distilled sterile water and decrease with the time. Distilled water favours most likely the grouping of virions and leads aggregates formation. The adsorption of øX-174 and MS2 onto K or M particles was instantaneous and independent of the duration contact. The clay concentration had a slight significant influence on the phage adsorption rate. Using the same phages we have studied, in a second stage, the potential effect of the dissolved matters in a filtered polluted effluent, that of sunlight radiations and that of the protozoan Tetrahymena pyriformis on the phage removal. No soon significant phage inactivation was

Contamination of Fresh Produce by Microbial Indicators on Farms and in Packing Facilities: Elucidation of Environmental Routes.

Science.gov (United States)

Bartz, Faith E; Lickness, Jacquelyn Sunshine; Heredia, Norma; Fabiszewski de Aceituno, Anna; Newman, Kira L; Hodge, Domonique Watson; Jaykus, Lee-Ann; García, Santos; Leon, Juan S

2017-06-01

To improve food safety on farms, it is critical to quantify the impact of environmental microbial contamination sources on fresh produce. However, studies are hampered by difficulties achieving study designs with powered sample sizes to elucidate relationships between environmental and produce contamination. Our goal was to quantify, in the agricultural production environment, the relationship between microbial contamination on hands, soil, and water and contamination on fresh produce. In 11 farms and packing facilities in northern Mexico, we applied a matched study design: composite samples ( n = 636, equivalent to 11,046 units) of produce rinses were matched to water, soil, and worker hand rinses during two growing seasons. Microbial indicators (coliforms, Escherichia coli , Enterococcus spp., and somatic coliphage) were quantified from composite samples. Statistical measures of association and correlations were calculated through Spearman's correlation, linear regression, and logistic regression models. The concentrations of all microbial indicators were positively correlated between produce and hands (ρ range, 0.41 to 0.75; P contamination of soil and water and contamination of produce. This methodology provides a foundation for future field studies, and results highlight the need for interventions surrounding farmworker hygiene and sanitation to reduce microbial contamination of farmworkers' hands. IMPORTANCE This study of the relationships between microbes on produce and in the farm environment can be used to support the design of targeted interventions to prevent or reduce microbial contamination of fresh produce with associated reductions in foodborne illness. Copyright © 2017 American Society for Microbiology.

Transport of Pathogen Surrogates in Soil Treatment Units: Numerical Modeling

Directory of Open Access Journals (Sweden)

Ivan Morales

2014-04-01

Full Text Available Segmented mesocosms (n = 3 packed with sand, sandy loam or clay loam soil were used to determine the effect of soil texture and depth on transport of two septic tank effluent (STE-borne microbial pathogen surrogates—green fluorescent protein-labeled E. coli (GFPE and MS-2 coliphage—in soil treatment units. HYDRUS 2D/3D software was used to model the transport of these microbes from the infiltrative surface. Mesocosms were spiked with GFPE and MS-2 coliphage at 105 cfu/mL STE and 105–106 pfu/mL STE, respectively. In all soils, removal rates were >99.99% at 25 cm. The transport simulation compared (1 optimization; and (2 trial-and-error modeling approaches. Only slight differences between the transport parameters were observed between these approaches. Treating both the die-off rates and attachment/detachment rates as variables resulted in an overall better model fit, particularly for the tailing phase of the experiments. Independent of the fitting procedure, attachment rates computed by the model were higher in sandy and sandy loam soils than clay, which was attributed to unsaturated flow conditions at lower water content in the coarser-textured soils. Early breakthrough of the bacteria and virus indicated the presence of preferential flow in the system in the structured clay loam soil, resulting in faster movement of water and microbes through the soil relative to a conservative tracer (bromide.

Spatio-temporal distribution of fecal indicators in three rivers of the Haihe River Basin, China.

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Wang, Yawei; Chen, Yanan; Zheng, Xiang; Gui, Chengmin; Wei, Yuansong

2017-04-01

Because of their significant impact on public health, waterborne pathogens, especially bacteria and viruses, are frequently monitored in surface water to assess microbial quality of water bodies. However, more than one billion people worldwide currently lack access to safe drinking water, and a diversity of waterborne outbreaks caused by pathogens is reported in nations at all levels of economic development. Spatio-temporal distribution of conventional pollutants and five pathogenic microorganisms were discussed for the Haihe River Basin. Land use and socio-economic assessments were coupled with comprehensive water quality monitoring. Physical, chemical, and biological parameters were measured at 20 different sites in the watershed for 1 year, including pH, temperature, conductivity, dissolved oxygen, turbidity, chemical oxygen demand, ammonia-N, total and fecal coliforms, E. coli, and Enterococcus. The results highlighted the high spatio-temporal variability in pathogen distribution at watershed scale: high concentration of somatic coliphages and fecal indicator bacteria in March and December and their very low concentration in June and September. All pathogens were positively correlated to urban/rural residential/industrial land and negatively correlated to other four land use types. Microbial pollution was greatly correlated with population density, urbanization rate, and percentage of the tertiary industry in the gross domestic product. In the future, river microbial risk control strategy should focus more on the effective management of secondary effluent of wastewater treatment plant and land around rivers.

Correlation of crAssphage-based qPCR markers with culturable and molecular indicators of human fecal pollution in an impacted urban watershed.

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Stachler, Elyse; Akyon, Benay; Aquino de Carvalho, Nathalia; Ference, Christian; Bibby, Kyle

2018-06-06

Environmental waters are monitored for fecal pollution to protect public health. Many previously developed human-specific fecal pollution indicators lack adequate sensitivity to be reliably detected in environmental waters or do not correlate well with viral pathogens. Recently, two novel human sewage-associated source tracking qPCR markers were developed based on the bacteriophage crAssphage, CPQ_056 and CPQ_064. These assays are highly human specific, abundant in sewage, and are viral-based, suggesting great promise for environmental application as human fecal pollution indicators. A 30-day sampling study was conducted in an urban stream impacted by combined sewer overflows to evaluate the crAssphage markers' performance in an environmental system. The crAssphage markers were present at concentrations of 4.02-6.04 log10 copies/100 mL throughout the study period, indicating their high abundance and ease of detection in polluted environmental waters. In addition, the crAssphage assays were correlated with rain events, molecular markers for human polyomavirus and HF183, as well as culturable E. coli, enterococci, and somatic coliphage. The CPQ_064 assay correlated strongly to a greater number of biological indicators than the CPQ_056 assay. This study is the first to evaluate both crAssphage qPCR assays in an extended environmental application of crAssphage markers for monitoring of environmental waters. It is also the first study to compare crAssphage marker concentration with other viral-based indicators.

Bacteriophage SP6 encodes a second tailspike protein that recognizes Salmonella enterica serogroups C2 and C3

International Nuclear Information System (INIS)

Gebhart, Dana; Williams, Steven R.; Scholl, Dean

2017-01-01

SP6 is a salmonella phage closely related to coliphage K1-5. K1-5 is notable in that it encodes two polysaccharide-degrading tailspike proteins, an endosialidase that allows it to infect E. coli K1, and a lyase that enables it to infect K5 strains. SP6 is similar to K1-5 except that it encodes a P22-like endorhamnosidase tailspike, gp46, allowing it to infect group B Salmonella. We show here that SP6 can also infect Salmonella serogroups C 2 and C 3 and that a mutation in a putative second tailspike, gp47, eliminates this specificity. Gene 47 was fused to the coding region of the N-terminal portion of the Pseudomonas aeruginosa R2 pyocin tail fiber and expressed in trans such that the fusion protein becomes incorporated into pyocin particles. These pyocins, termed AvR2-SP47, killed serogroups C 2 and C 3 Salmonella. We conclude that SP6 encodes two tail proteins providing it a broad host range among Salmonella enterica. - Highlights: • SP6 is a “dual specificity” bacteriophage that encodes two different receptor binding proteins giving it a broad host range. • These receptor binding proteins can be used to re-target the spectrum of R-type bacteriocins to Salmonella enterica. • Both SP6 and the engineered R-type bacteriocins can kill the Salmonella serovars most associated with human disease making them attractive for development as antimicrobial agents.

Comparison of filters for concentrating microbial indicators and pathogens in lake-water samples

Science.gov (United States)

Francy, Donna S.; Stelzer, Erin A.; Brady, Amie M.G.; Huitger, Carrie; Bushon, Rebecca N.; Ip, Hon S.; Ware, Michael W.; Villegas, Eric N.; Gallardo, Vincent; Lindquist, H.D. Alan

2013-01-01

Bacterial indicators are used to indicate increased health risk from pathogens and to make beach closure and advisory decisions; however, beaches are seldom monitored for the pathogens themselves. Studies of sources and types of pathogens at beaches are needed to improve estimates of swimming-associated health risks. It would be advantageous and cost-effective, especially for studies conducted on a regional scale, to use a method that can simultaneously filter and concentrate all classes of pathogens from the large volumes of water needed to detect pathogens. In seven recovery experiments, stock cultures of viruses and protozoa were seeded into 10-liter lake water samples, and concentrations of naturally occurring bacterial indicators were used to determine recoveries. For the five filtration methods tested, the highest median recoveries were as follows: glass wool for adenovirus (4.7%); NanoCeram for enterovirus (14.5%) and MS2 coliphage (84%); continuous-flow centrifugation (CFC) plus Virocap (CFC+ViroCap) for Escherichia coli (68.3%) and Cryptosporidium (54%); automatic ultrafiltration (UF) for norovirus GII (2.4%); and dead-end UF for Enterococcus faecalis (80.5%), avian influenza virus (0.02%), and Giardia (57%). In evaluating filter performance in terms of both recovery and variability, the automatic UF resulted in the highest recovery while maintaining low variability for all nine microorganisms. The automatic UF was used to demonstrate that filtration can be scaled up to field deployment and the collection of 200-liter lake water samples.

Bacteriophages as indicators of faecal pollution and enteric virus removal.

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McMinn, B R; Ashbolt, N J; Korajkic, A

2017-07-01

Bacteriophages are an attractive alternative to faecal indicator bacteria (FIB), particularly as surrogates of enteric virus fate and transport, due to their closer morphological and biological properties. Based on a review of published data, we summarize densities of coliphages (F+ and somatic), Bacteroides spp. and enterococci bacteriophages (phages) in individual human waste, raw wastewater, ambient fresh and marine waters and removal through wastewater treatment processes utilizing traditional treatments. We also provide comparisons with FIB and enteric viruses whenever possible. Lastly, we examine fate and transport characteristics in the aquatic environment and provide an overview of the environmental factors affecting their survival. In summary, concentrations of bacteriophages in various sources were consistently lower than FIB, but more reflective of infectious enteric virus levels. Overall, our investigation indicates that bacteriophages may be adequate viral surrogates, especially in built systems, such as wastewater treatment plants. Bacteriophage are alternative fecal indicators that may be better surrogates for viral pathogens than fecal indicator bacteria (FIB). This report offers a summary of the existing literature concerning the utility of bacteriophage as indicators of viral presence (fecal sources and surface waters) and persistence (in built infrastructure and aquatic environments). Our findings indicate that bacteriophage levels in all matrices examined are consistently lower than FIB, but similar to viral pathogens. Furthermore, in built infrastructure (e.g. wastewater treatment systems) bacteriophage closely mimic viral pathogen persistence suggesting they may be adequate sentinels of enteric virus removal. © 2017 The Society for Applied Microbiology.

Iron oxide-mediated semiconductor photocatalysis vs. heterogeneous photo-Fenton treatment of viruses in wastewater. Impact of the oxide particle size.

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Giannakis, Stefanos; Liu, Siting; Carratalà, Anna; Rtimi, Sami; Talebi Amiri, Masoud; Bensimon, Michaël; Pulgarin, César

2017-10-05

The photo-Fenton process is recognized as a promising technique towards microorganism disinfection in wastewater, but its efficiency is hampered at near-neutral pH operating values. In this work, we overcome these obstacles by using the heterogeneous photo-Fenton process as the default disinfecting technique, targeting MS2 coliphage in wastewater. The use of low concentrations of iron oxides in wastewater without H 2 O 2 (wüstite, maghemite, magnetite) has demonstrated limited semiconductor-mediated MS2 inactivation. Changing the operational pH and the size of the oxide particles indicated that the isoelectric point of the iron oxides and the active surface area are crucial in the success of the process, and the possible underlying mechanisms are investigated. Furthermore, the addition of low amounts of Fe-oxides (1mgL -1 ) and H 2 O 2 in the system (1, 5 and 10mgL -1 ) greatly enhanced the inactivation process, leading to heterogeneous photo-Fenton processes on the surface of the magnetically separable oxides used. Additionally, photo-dissolution of iron in the bulk, lead to homogeneous photo-Fenton, further aided by the complexation by the dissolved organic matter in the solution. Finally, we assess the impact of the presence of the bacterial host and the difference caused by the different iron sources (salts, oxides) and the Fe-oxide size (normal, nano-sized). Copyright © 2017 Elsevier B.V. All rights reserved.

Phage T4 endonuclease V stimulates DNA repair replication in isolated nuclei from ultraviolet-irradiated human cells, including xeroderma pigmentosum fibroblasts

International Nuclear Information System (INIS)

Smith, C.A.; Hanawalt, P.C.

1978-01-01

The repair mode of DNA replication has been demonstrated in isolated nuclei from uv-irradiated human cells. Nuclei are incubated in a mixture containing [ 3 H]thymidine triphosphate and bromodeoxyuridine triphosphate in a 1:5 ratio. The 3 H at the density of parental DNA in alkaline CsCl density gradients is then a measure of repair. In nuclei prepared from WI38 cells 30 min after irradiation, repair replication is uv-dependent and proceeds at approximately the in vivo rate for 5 min. Repair replication is reduced in irradiated nuclei or in nuclei prepared immediately after irradiation. It is Mg 2+ -dependent and stimulated by added ATP and deoxyribonucleoside triphosphates. No repair replication is observed in nuclei from xeroderma pigmentosum (complementation group A) cells. However, upon addition of coliphage T4 endonuclease V, which specifically nicks DNA containing pyrimidine dimers, repair replication is observed in nuclei from irradiated xeroderma pigmentosum cells and is stimulated in WI38 nuclei. The reaction then persists for an hour and is dependent upon added ATP and deoxyribonucleoside triphosphates. The repair label is in stretches of roughly 35 nucleotides, as it is in intact cells. Added pancreatic DNase does not promote uv-dependent repair synthesis. Our results support the view that xeroderma pigmentosum (group A) cells are defective in the incision step of the DNA excision repair pathway, and demonstrate the utility of this system for probing DNA repair mechanisms

Effect of environmental parameters on pathogen and faecal indicator organism concentrations within an urban estuary

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Henry, Rebekah; Schang, Christelle; Kolotelo, Peter; Coleman, Rhys; Rooney, Graham; Schmidt, Jonathan; Deletic, Ana; McCarthy, David T.

2016-06-01

Current World Health Organisation figures estimate that ∼2.5 million deaths per year result from recreational contact with contaminated water sources. Concerns about quantitative risk assessments of waterways using faecal indicator organisms (FIOs) as surrogates to infer pathogenic risk currently exist. In Melbourne, Australia, the Yarra River has come under public scrutiny due to perceived public health risks associated with aquatic recreation; a characteristic shared with urban estuaries worldwide. A 10-month study of the Yarra estuary investigated the processes that affect FIOs and pathogens within this system. A total of 74 samples were collected from three estuarine and two upstream, freshwater, locations under different climatic and hydrological conditions, and the levels of Escherichia coli, enterococci, Clostridium perfringens, fRNA coliphages, Campylobacter spp. Cryptosporidium oocysts, Giardia cysts, adenoviruses, and enteroviruses were monitored. Reference pathogenic bacteria, protozoa, and viruses were detected in 81%, 19%, and 8% of samples, respectively. Variations in FIO concentrations were found to be associated with changes in specific climatic and hydrological variables including: temperature, flow, humidity and rainfall. In contrast, pathogen levels remained unaffected by all variables investigated. Limitations of current national and international culture-based standard methods may have played a significant role in limiting the identification of correlative relationships The data demonstrate the differences between FIOs and microbial pathogens in terms of sources, sinks, and survival processes within an urban estuary and provide further evidence of the inadequacy of FIO inclusion in the development of worldwide regulatory water quality criteria and risk assessment models.

In vivo efficiency evaluation of a phage cocktail in controlling severe colibacillosis in confined conditions and experimental poultry houses.

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Oliveira, Ana; Sereno, Rui; Azeredo, Joana

2010-12-15

Infections caused by avian pathogenic Escherichia coli (APEC) cause important economic losses to poultry industry. The studies presented herein, aimed at investigating the in vivo performance of a cocktail of three phages in treating severe respiratory E. coli infections in experimentally contaminated birds and naturally infected flocks. Three lytic coliphages, phi F78E (Myoviridae), phi F258E (Siphoviridae) and phi F61E (Myoviridae) were combined in a 5.0 × 10(7)PFU/ml cocktail to be used in naturally APEC infected flocks (refractive to antibiotherapy). Experimentally infected birds were treated with phi F78E at two different titres (10(7)PFU/ml and 10(9)PFU/ml). Phage administration was performed orally and by spray, in a single application. The morbidity, mortality and pathology scores were compared with control birds not receiving phage therapy. The results revealed that the success of phage therapy in experimental rooms was dosage dependent, being 10(7)PFU/ml not enough to treat the infected chickens whereas a concentration of 10(9)PFU/ml of phi F78E allowed a decrease of 25% and 43% in chickens' mortality and morbidity, respectively. In the large scale experiments, the results obtained showed a remarkable efficacy of the low titre phage cocktail (10(7)PFU/ml) in decreasing the flocks' mortality to levels below 0.5% in no more than 3 weeks, with no recidivism. Based on the results we can conclude that phage treatment is a valuable alternative to control APEC infections in poultry. Copyright © 2010 Elsevier B.V. All rights reserved.

Bacteriophage SP6 encodes a second tailspike protein that recognizes Salmonella enterica serogroups C{sub 2} and C{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Gebhart, Dana; Williams, Steven R.; Scholl, Dean, E-mail: dean@avidbiotics.com

2017-07-15

SP6 is a salmonella phage closely related to coliphage K1-5. K1-5 is notable in that it encodes two polysaccharide-degrading tailspike proteins, an endosialidase that allows it to infect E. coli K1, and a lyase that enables it to infect K5 strains. SP6 is similar to K1-5 except that it encodes a P22-like endorhamnosidase tailspike, gp46, allowing it to infect group B Salmonella. We show here that SP6 can also infect Salmonella serogroups C{sub 2} and C{sub 3} and that a mutation in a putative second tailspike, gp47, eliminates this specificity. Gene 47 was fused to the coding region of the N-terminal portion of the Pseudomonas aeruginosa R2 pyocin tail fiber and expressed in trans such that the fusion protein becomes incorporated into pyocin particles. These pyocins, termed AvR2-SP47, killed serogroups C{sub 2} and C{sub 3}Salmonella. We conclude that SP6 encodes two tail proteins providing it a broad host range among Salmonella enterica. - Highlights: • SP6 is a “dual specificity” bacteriophage that encodes two different receptor binding proteins giving it a broad host range. • These receptor binding proteins can be used to re-target the spectrum of R-type bacteriocins to Salmonella enterica. • Both SP6 and the engineered R-type bacteriocins can kill the Salmonella serovars most associated with human disease making them attractive for development as antimicrobial agents.

Integration of an innovative biological treatment with physical or chemical disinfection for wastewater reuse.

Science.gov (United States)

De Sanctis, Marco; Del Moro, Guido; Levantesi, Caterina; Luprano, Maria Laura; Di Iaconi, Claudio

2016-02-01

In the present paper, the effectiveness of a Sequencing Batch Biofilter Granular Reactor (SBBGR) and its integration with different disinfection strategies (UV irradiation, peracetic acid) for producing an effluent suitable for agricultural use was evaluated. The plant treated raw domestic sewage, and its performances were evaluated in terms of the removal efficiency of a wide group of physical, chemical and microbiological parameters. The SBBGR resulted really efficient in removing suspended solids, COD and nitrogen with an average effluent concentration of 5, 32 and 10 mg/L, respectively. Lower removal efficiency was observed for phosphorus with an average concentration in the effluent of 3 mg/L. Plant effluent was also characterized by an average electrical conductivity and sodium adsorption ratio of 680 μS/cm and 2.9, respectively. Therefore, according to these gross parameters, the SBBGR effluent was conformed to the national standards required in Italy for agricultural reuse. Moreover, disinfection performances of the SBBGR was higher than that of conventional municipal wastewater treatment plants and met the quality criteria suggested by WHO (Escherichia colidisinfection processes (UV and peracetic acid) resulted very effective for total coliforms, E. coli and somatic coliphages. In particular, a UV radiation and peracetic acid doses of 40 mJ/cm(2) and 1 mg/L respectively reduced E. coli content in the effluent below the limit for agricultural reuse in Italy (10 CFU/100 mL). Conversely, they were both ineffective on C.perfringens spores. Copyright © 2015 Elsevier B.V. All rights reserved.

Development of a novel method for simultaneous concentration of viruses and protozoa from a single water sample.

Science.gov (United States)

Haramoto, Eiji; Katayama, Hiroyuki; Asami, Mari; Akiba, Michihiro

2012-06-01

A novel method, electronegative membrane-vortex (EMV) method, was developed for simultaneous concentration of viruses and protozoa from a single water sample. Viruses and protozoa in a water sample were mixed with a cation solution and adsorbed on an electronegative membrane. Concentrated virus and protozoa samples were obtained as supernatant and pellet fractions, respectively, by vigorous vortex mixing of the membrane and centrifugation of the eluted material. The highest recovery efficiencies of model microbes from river water and tap water by this EMV method were obtained using a mixed cellulose ester membrane with a pore size of 0.45 μm (Millipore) as the electronegative membrane and MgCl(2) as the cation solution. The recovery was 27.7-86.5% for poliovirus, 25.7-68.3% for coliphage Qβ, 28.0-60.0% for Cryptosporidium oocysts, and 35.0-53.0% for Giardia cysts. The EMV method detected successfully indigenous viruses and protozoa in wastewater and river water samples from the Kofu basin, Japan, showing an overall positive rate of 100% (43/43) for human adenovirus, 79% (34/43) for norovirus GI, 65% (28/43) for norovirus GII, 23% (10/43) for Cryptosporidium oocysts, and 60% (26/43) for Giardia cysts. By direct DNA sequencing, a total of four genotypes (AI, AII, B, and G) of Giardia intestinalis were identified in the water samples, indicating that the river water was contaminated with feces from various mammals, including humans. Copyright © 2012 Elsevier B.V. All rights reserved.

Role of hydraulic retention time and granular medium in microbial removal in tertiary treatment reed beds.

Science.gov (United States)

García, Joan; Vivar, Joan; Aromir, Maria; Mujeriego, Rafael

2003-06-01

The main objective of this paper is to evaluate the role of hydraulic retention time (HRT) and granular medium in faecal coliform (FC) and somatic coliphage (SC) removal in tertiary reed beds. Experiments were carried out in a pilot plant with four parallel reed beds (horizontal subsurface flow constructed wetlands), each one containing a different type of granular medium. This pilot plant is located in a wastewater treatment plant in Montcada i Reixac, near Barcelona, in northeastern Spain. The microbial inactivation ratios obtained in the different beds are compared as a function of three selected HRTs. Secondary effluent from the wastewater treatment plant was used as the influent of the pilot system. The microbial inactivation ratio ranged between 0.1 and 2.7 log-units for FC and from 0.5 to 1.7 log-units for SC in beds with coarser granular material (5-25mm), while it ranged between 0.7 and 3.4 log-units for FC and from 0.9 to 2.6 log-units for SC in the bed with finer material (2-13mm). HRT and granular medium are both key factors in microbial removal in the tertiary reed beds. The microbial inactivation ratio rises as the HRT increases until it reaches a saturation value (in general at an HRT of 3 days). The value of the microbial inactivation ratio at the saturation level depends on the granular medium contained in the bed. The specific surface area necessary to reach 2-3 log-units of FC and SC is approximately 3m(2)/person-equivalent.

Evaluating UV-C LED disinfection performance and investigating potential dual-wavelength synergy.

Science.gov (United States)

Beck, Sara E; Ryu, Hodon; Boczek, Laura A; Cashdollar, Jennifer L; Jeanis, Kaitlyn M; Rosenblum, James S; Lawal, Oliver R; Linden, Karl G

2017-02-01

A dual-wavelength UV-C LED unit, emitting at peaks of 260 nm, 280 nm, and the combination of 260|280 nm together was evaluated for its inactivation efficacy and energy efficiency at disinfecting Escherichia coli, MS2 coliphage, human adenovirus type 2 (HAdV2), and Bacillus pumilus spores, compared to conventional low-pressure and medium-pressure UV mercury vapor lamps. The dual-wavelength unit was also used to measure potential synergistic effects of multiple wavelengths on bacterial and viral inactivation and DNA and RNA damage. All five UV sources demonstrated similar inactivation of E. coli. For MS2, the 260 nm LED was most effective. For HAdV2 and B. pumilus, the MP UV lamp was most effective. When measuring electrical energy per order of reduction, the LP UV lamp was most efficient for inactivating E. coli and MS2; the LP UV and MP UV mercury lamps were equally efficient for HAdV2 and B. pumilus spores. Among the UV-C LEDs, there was no statistical difference in electrical efficiency for inactivating MS2, HAdV2, and B. pumilus spores. The 260 nm and 260|280 nm LEDs had a statistical energy advantage for E. coli inactivation. For UV-C LEDs to match the electrical efficiency per order of log reduction of conventional LP UV sources, they must reach efficiencies of 25-39% or be improved on by smart reactor design. No dual wavelength synergies were detected for bacterial and viral inactivation nor for DNA and RNA damage. Copyright © 2016 Elsevier Ltd. All rights reserved.

Reduction in infection risk through treatment of microbially contaminated surfaces with a novel, portable, saturated steam vapor disinfection system.

Science.gov (United States)

Tanner, Benjamin D

2009-02-01

Surface-mediated infectious disease transmission is a major concern in various settings, including schools, hospitals, and food-processing facilities. Chemical disinfectants are frequently used to reduce contamination, but many pose significant risks to humans, surfaces, and the environment, and all must be properly applied in strict accordance with label instructions to be effective. This study set out to determine the capability of a novel chemical-free, saturated steam vapor disinfection system to kill microorganisms, reduce surface-mediated infection risks, and serve as an alternative to chemical disinfectants. High concentrations of Escherichia coli, Shigella flexneri, vancomycin-resistant Enterococcus faecalis (VRE), methicillin-resistant Staphylococcus aureus (MRSA), Salmonella enterica, methicillin-sensitive Staphylococcus aureus, MS2 coliphage (used as a surrogate for nonenveloped viruses including norovirus), Candida albicans, Aspergillus niger, and the endospores of Clostridium difficile were dried individually onto porous clay test surfaces. Surfaces were treated with the saturated steam vapor disinfection system for brief periods and then numbers of surviving microorganisms were determined. Infection risks were calculated from the kill-time data using microbial dose-response relationships published in the scientific literature, accounting for surface-to-hand and hand-to-mouth transfer efficiencies. A diverse assortment of pathogenic microorganisms was rapidly killed by the steam disinfection system; all of the pathogens tested were completely inactivated within 5 seconds. Risks of infection from the contaminated surfaces decreased rapidly with increasing periods of treatment by the saturated steam vapor disinfection system. The saturated steam vapor disinfection system tested for this study is chemical-free, broadly active, rapidly efficacious, and therefore represents a novel alternative to liquid chemical disinfectants.

Fotocatálise heterogênea com TiO2 aplicada ao tratamento de esgoto sanitário secundário TiO2 heterogeneous photocatalysis in secondary wastewater treatment

Directory of Open Access Journals (Sweden)

Ivete Vasconcelos Lopes Ferreira

2004-12-01

Full Text Available Neste trabalho são apresentados resultados da aplicação da fotocatálise heterogênea utilizando dióxido de titânio imobilizado sobre placa de vidro, irradiado por luz solar, para desinfecção de esgoto sanitário secundário. Utilizou-se o efluente de um reator anaeróbio/aeróbio com leito expandido de carvão ativado que trata o esgoto do Campus da USP/São Carlos, e também de contribuições domésticas. Os experimentos foram do tipo batelada, com tempo de recirculação de 4 horas. As vazões estudadas foram 15, 22,5 e 30 L/h. Foram avaliadas as remoções de matéria orgânica (DQO e COT e a inativação de microrganismos indicadores de contaminação fecal (coliformes totais, E. coli, Clostridium perfringens e colifagos.The results of wastewater anaerobic-aerobic reactor effluent disinfected with heterogeneous photocatalysis using titanium dioxide fixed in a glass plate and solar radiation are presented in this work. The anaerobic-aerobic reactor has a granular activated carbon expanded bed and it receives the wastewater collected in the Campus of São Paulo University at São Carlos-SP, Brazil, and from the surrounding neighborhood of the campus. The assays were conducted in batch with recirculation time of 4 hours. The flow rate used was of 15, 22.5 and 30 L/h. The removal of organic matter (COD and TOC and inactivation of total coliforms, E. coli, Clostridium perfringens and coliphages was evaluated.

Chitosan Coagulation to Improve Microbial and Turbidity Removal by Ceramic Water Filtration for Household Drinking Water Treatment.

Science.gov (United States)

Abebe, Lydia S; Chen, Xinyu; Sobsey, Mark D

2016-02-27

The use of porous ceramic filters is promoted globally for household water treatment, but these filters are ineffective in removing viruses from water. In order to increase virus removal, we combine a promising natural coagulant, chitosan, as a pretreatment for ceramic water filters (CWFs) and evaluate the performance of this dual barrier water treatment system. Chitosan is a non-toxic and biodegradable organic polymer derived by simple chemical treatments from chitin, a major source of which is the leftover shells of crustacean seafoods, such as shrimp, prawns, crabs, and lobsters. To determine the effectiveness of chitosan, model test water was contaminated with Escherichia coli K011 and coliphage MS2 as a model enteric bacterium and virus, respectively. Kaolinite clay was used to model turbidity. Coagulation effectiveness of three types of modified chitosans was determine at various doses ranging from 5 to 30 mg/L, followed by flocculation and sedimentation. The pre-treated supernatant water was then decanted into the CWF for further treatment by filtration. There were appreciable microbial removals by chitosan HCl, acetate, and lactate pretreatment followed by CWF treatment, with mean reductions (95% CI) between 4.7 (± 1.56) and 7.5 (± 0.02) log10 for Escherichia coli, and between 2.8 (± 0.10) and 4.5 (± 1.04) log10 for MS2. Turbidity reduction with chitosan treatment and filtration consistently resulted in turbidities water treatment technology, chitosan coagulation achieved health protective targets for both viruses and bacteria. Therefore, the results of this study support the use of chitosan to improve household drinking water filtration processes by increasing virus and bacteria reductions.

Bacterial and fungal biofilm formation on contact lenses and their susceptibility to lens care solutions

Directory of Open Access Journals (Sweden)

Siddharth Kackar

2017-01-01

Full Text Available Background: Microbial biofilm formation on contact lenses and lens storage cases may be a risk factor for contact lens-associated corneal infections. Various types of contact lens care solutions are used to reduce microbial growths on lenses. Objectives: The present study aimed at comparing the growths of biofilms on the different contact lenses and lens cases. The study also aimed at determining the effect of lens care solutions and bacteriophage on these biofilms. Materials and Methods: One type of hard lens and two types of soft lenses were used for the study. The organisms used were Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853, Candida albicans ATCC 60193 and Escherichia coli ATCC 25922. Biofilm production was performed by modified O'Toole and Kolter method and effect of lens cleaning solutions and a crude coliphage on biofilms was also studied. Results were visualised using scanning electron microscopy and quantitated by colony counting method and spectrophotometric measurement of optical density (OD. Statistical analysis was done by SPSS 11.5, Kruskal–Wallis test and Chi-square test. Results: Soft lens cleaning solutions had a significant inhibitory effect (P = 0.020 on biofilm formation on soft lenses and also lens cases (P < 0.001. Soft lens cleaning solution 2 was more efficient than solution 1. However, no such inhibitory effect was observed with regard to hard lens cleaning solution, but for a significant reduction in the OD values (P < 0.001. There was no significant inhibitory effect by bacteriophages. Conclusion: This study showed the importance of selecting the appropriate lens cleaning solution to prevent biofilm production on contact lenses.

Peracetic acid (PAA) disinfection of primary, secondary and tertiary treated municipal wastewaters.

Science.gov (United States)

Koivunen, J; Heinonen-Tanski, H

2005-11-01

The efficiency of peracetic acid (PAA) disinfection against enteric bacteria and viruses in municipal wastewaters was studied in pilot-scale. Disinfection pilot-plant was fed with the primary or secondary effluent of Kuopio municipal wastewater treatment plant or tertiary effluent from the pilot-scale dissolved air flotation (DAF) unit. Disinfectant doses ranged from 2 to 7 mg/l PAA in the secondary and tertiary effluents, and from 5 to 15 mg/l PAA in the primary effluents. Disinfection contact times were 4-27 min. Disinfection of secondary and tertiary effluents with 2-7 mg/l PAA and 27 min contact time achieved around 3 log reductions of total coliforms (TC) and enterococci (EC). PAA disinfection also significantly improved the hygienic quality of the primary effluents: 10-15 mg/l PAA achieved 3-4 log reductions of TC and EC, 5 mg/l PAA resulting in below 2 log reductions. F-RNA coliphages were more resistant against the PAA disinfection and around 1 log reductions of these enteric viruses were typically achieved in the disinfection treatments of the primary, secondary and tertiary effluents. Most of the microbial reductions occurred during the first 4-18 min of contact time, depending on the PAA dose and microorganism. The PAA disinfection efficiency remained relatively constant in the secondary and tertiary effluents, despite of small changes of wastewater quality (COD, SS, turbidity, 253.7 nm transmittance) or temperature. The disinfection efficiency clearly decreased in the primary effluents with substantially higher microbial, organic matter and suspended solids concentrations. The results demonstrated that PAA could be a good alternative disinfection method for elimination of enteric microbes from different wastewaters.

Effect of ultrasound, low-temperature thermal and alkali pre-treatments on waste activated sludge rheology, hygienization and methane potential.

Science.gov (United States)

Ruiz-Hernando, M; Martín-Díaz, J; Labanda, J; Mata-Alvarez, J; Llorens, J; Lucena, F; Astals, S

2014-09-15

Waste activated sludge is slower to biodegrade under anaerobic conditions than is primary sludge due to the glycan strands present in microbial cell walls. The use of pre-treatments may help to disrupt cell membranes and improve waste activated sludge biodegradability. In the present study, the effect of ultrasound, low-temperature thermal and alkali pre-treatments on the rheology, hygienization and biodegradability of waste activated sludge was evaluated. The optimum condition of each pre-treatment was selected based on rheological criteria (reduction of steady state viscosity) and hygienization levels (reduction of Escherichia coli, somatic coliphages and spores of sulfite-reducing clostridia). The three pre-treatments were able to reduce the viscosity of the sludge, and this reduction was greater with increasing treatment intensity. However, only the alkali and thermal conditioning allowed the hygienization of the sludge, whereas the ultrasonication did not exhibit any notorious effect on microbial indicators populations. The selected optimum conditions were as follows: 27,000 kJ/kg TS for the ultrasound, 80 °C during 15 min for the thermal and 157 g NaOH/kg TS for the alkali. Afterward, the specific methane production was evaluated through biomethane potential tests at the specified optimum conditions. The alkali pre-treatment exhibited the greatest methane production increase (34%) followed by the ultrasonication (13%), whereas the thermal pre-treatment presented a methane potential similar to the untreated sludge. Finally, an assessment of the different treatment scenarios was conducted considering the results together with an energy balance, which revealed that the ultrasound and alkali treatments entailed higher costs. Copyright © 2014 Elsevier Ltd. All rights reserved.

Microbiological indicators of water quality in the Xochimilco canals, Mexico City Indicadores microbiológicos de la calidad del agua de los canales de Xochimilco de la Ciudad de México

Directory of Open Access Journals (Sweden)

Luis Alfredo Juárez-Figueroa

2003-10-01

Full Text Available OBJECTIVE: To quantify microbiology indicators of fecal contamination in the effluents of two waste water treatment plants and in samples collected in several canals in Xochimilco. MATERIAL AND METHODS: A cross sectional study was performed. Ten sites, 5 from plant effluents and 5 from canals, were selected for sampling during November and December 2001. Fecal coliforms and enterococci were quantified by membrane filtration, male specific (F+ and somatic coliphages by double agar layer technique, and Cryptosporidium oocysts and Giardia cysts by concentration with Envirocheck filter followed by immunofluorescence microscopy quantification.The average of organisms counts from effluents and canal water were compared with t Student test. RESULTS: Treated water discharge in canals showed a low count of Fecal Coliforms (average 40.4/100 ml, enterococci (average 58.8/100 ml and Cryptosporidium oocysts (average 13.2/100 l, while coliphages and Giardia cyst rendered higher counts (average 1467.5/100 ml and 1199.8/100 l, respectively suggesting the water treatment methods could fail to remove these agents. A significant lower count of Giardia cysts (average 45/100 l and no Cryptosporidium oocysts were found in irrigation canals, which suggests a natural clearance of these pathogens. Strains of Escherichia coli isolated in one of the canals contaminated with sewage had antimicrobial multi-resistance that was transferred by conjugation suggesting that resistance is encoded in a plasmid potentially transferable to other pathogenic bacteria. CONCLUSIONS: Cost effective and culturally acceptable waste treatment methods will require careful planning and consultation if they are to be adopted and mantained by local populations.OBJETIVO: Cuantificar diversos indicadores de contaminación fecal en los efluentes de dos plantas de tratamiento de aguas residuales y en muestras recogidas en varios canales de Xochimilco. MATERIAL Y MÉTODOS: Estudio transversal

Multiple lines of evidence to identify sewage as the cause of water quality impairment in an urbanized tropical watershed.

Science.gov (United States)

Kirs, Marek; Kisand, Veljo; Wong, Mayee; Caffaro-Filho, Roberto A; Moravcik, Philip; Harwood, Valerie J; Yoneyama, Bunnie; Fujioka, Roger S

2017-06-01

Indicator bacteria, which are conventionally used to evaluate recreational water quality, can originate from various non-human enteric and extra-enteric sources, hence they may not be indicative of human health risk nor do they provide information on the sources of contamination. In this study we utilized traditional (enterococci and Escherichia coli) and alternative (Clostridium perfringens) indicator bacteria, F + -specific coliphage, molecular markers for microorganisms associated with human sewage (human-associated Bacteroides and polyomaviruses), and microbial community analysis tools (16S rRNA gene fragment amplicon sequencing), to identify and evaluate human sewage-related impact in the Manoa watershed in Honolulu, Hawaii. Elevated concentrations of enterococci (geometric mean ranging from 1604 to 2575 CFU 100 mL -1 ) and C. perfringens (45-77 CFU 100 mL -1 ) indicated impairment of the urbanized section of the stream, while indicator bacteria concentrations decreased downstream in the tidally influenced Ala Wai Canal. The threshold values triggering water quality violation notifications in Hawaii were exceeded in 33.3-75.0% of samples collected at sites in the urbanized section of Manoa Stream, but were not exceeded in any of the samples collected at an upstream site located in a forested area. Correlation between indicator bacteria concentrations and rainfall amounts was weak to moderate but significant (E. coli R = 0.251, P = 0.009; enterococci R = 0.369, P watershed, it was lower in the impaired section. Leaking sewer systems and illegal cross-connections are implicated in the impairment of the watershed, hence both the sewer and the storm water lines should be routinely inspected. Collectively, our data suggest that information derived from the analysis of microbial communities complements current marker-based microbial source tracking techniques and environmental monitoring programs. Copyright © 2017 Elsevier Ltd. All rights reserved.

Importance of the colmation layer in the transport and removal of cyanobacteria, viruses, and dissolved organic carbon during natural lake-bank filtration

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Harvey, Ronald W.; Metge, David W.; LeBlanc, Denis R.; Underwood, Jennifer C.; Aiken, George R.; Butler, Kenna D.; McCobb, Timothy D.; Jasperse, Jay

2015-01-01

This study focused on the importance of the colmation layer in the removal of cyanobacteria, viruses, and dissolved organic carbon (DOC) during natural bank filtration. Injection-and-recovery studies were performed at two shallow (0.5 m deep), sandy, near-shore sites at the southern end of Ashumet Pond, a waste-impacted, kettle pond on Cape Cod, MA, that is subject to periodic blooms of cyanobacteria and continuously recharges a sole-source drinking-water aquifer. The experiment involved assessing the transport behaviors of bromide (conservative tracer), Synechococcus sp. IU625 (cyanobacterium, 2.6 ± 0.2 µm), AS-1 (tailed cyanophage, 110 nm long), MS2 (coliphage, 26 nm diameter), and carboxylate-modified microspheres (1.7 µm diameter) introduced to the colmation layer using a bag-and-barrel (Lee-type) seepage meter. The injectate constituents were tracked as they were advected across the pond water–groundwater interface and through the underlying aquifer sediments under natural-gradient conditions past push-point samplers placed at ∼30-cm intervals along a 1.2-m-long, diagonally downward flow path. More than 99% of the microspheres, IU625, MS2, AS-1, and ∼44% of the pond DOC were removed in the colmation layer (upper 25 cm of poorly sorted bottom sediments) at two test locations characterized by dissimilar seepage rates (1.7 vs. 0.26 m d−1). Retention profiles in recovered core material indicated that >82% of the attached IU625 were in the top 3 cm of bottom sediments. The colmation layer was also responsible for rapid changes in the character of the DOC and was more effective (by three orders of magnitude) at removing microspheres than was the underlying 20-cm-thick segment of sediment.

The genome and structural proteome of an ocean siphovirus: a new window into the cyanobacterial 'mobilome'.

Science.gov (United States)

Sullivan, Matthew B; Krastins, Bryan; Hughes, Jennifer L; Kelly, Libusha; Chase, Michael; Sarracino, David; Chisholm, Sallie W

2009-11-01

Prochlorococcus, an abundant phototroph in the oceans, are infected by members of three families of viruses: myo-, podo- and siphoviruses. Genomes of myo- and podoviruses isolated on Prochlorococcus contain DNA replication machinery and virion structural genes homologous to those from coliphages T4 and T7 respectively. They also contain a suite of genes of cyanobacterial origin, most notably photosynthesis genes, which are expressed during infection and appear integral to the evolutionary trajectory of both host and phage. Here we present the first genome of a cyanobacterial siphovirus, P-SS2, which was isolated from Atlantic slope waters using a Prochlorococcus host (MIT9313). The P-SS2 genome is larger than, and considerably divergent from, previously sequenced siphoviruses. It appears most closely related to lambdoid siphoviruses, with which it shares 13 functional homologues. The approximately 108 kb P-SS2 genome encodes 131 predicted proteins and notably lacks photosynthesis genes which have consistently been found in other marine cyanophage, but does contain 14 other cyanobacterial homologues. While only six structural proteins were identified from the genome sequence, 35 proteins were detected experimentally; these mapped onto capsid and tail structural modules in the genome. P-SS2 is potentially capable of integration into its host as inferred from bioinformatically identified genetic machinery int, bet, exo and a 53 bp attachment site. The host attachment site appears to be a genomic island that is tied to insertion sequence (IS) activity that could facilitate mobility of a gene involved in the nitrogen-stress response. The homologous region and a secondary IS-element hot-spot in Synechococcus RS9917 are further evidence of IS-mediated genome evolution coincident with a probable relic prophage integration event. This siphovirus genome provides a glimpse into the biology of a deep-photic zone phage as well as the ocean cyanobacterial prophage and IS element

The genome and structural proteome of an ocean siphovirus: a new window into the cyanobacterial ‘mobilome’

Science.gov (United States)

Sullivan, Matthew B; Krastins, Bryan; Hughes, Jennifer L; Kelly, Libusha; Chase, Michael; Sarracino, David; Chisholm, Sallie W

2009-01-01

Prochlorococcus, an abundant phototroph in the oceans, are infected by members of three families of viruses: myo-, podo- and siphoviruses. Genomes of myo- and podoviruses isolated on Prochlorococcus contain DNA replication machinery and virion structural genes homologous to those from coliphages T4 and T7 respectively. They also contain a suite of genes of cyanobacterial origin, most notably photosynthesis genes, which are expressed during infection and appear integral to the evolutionary trajectory of both host and phage. Here we present the first genome of a cyanobacterial siphovirus, P-SS2, which was isolated from Atlantic slope waters using a Prochlorococcus host (MIT9313). The P-SS2 genome is larger than, and considerably divergent from, previously sequenced siphoviruses. It appears most closely related to lambdoid siphoviruses, with which it shares 13 functional homologues. The ∼108 kb P-SS2 genome encodes 131 predicted proteins and notably lacks photosynthesis genes which have consistently been found in other marine cyanophage, but does contain 14 other cyanobacterial homologues. While only six structural proteins were identified from the genome sequence, 35 proteins were detected experimentally; these mapped onto capsid and tail structural modules in the genome. P-SS2 is potentially capable of integration into its host as inferred from bioinformatically identified genetic machinery int, bet, exo and a 53 bp attachment site. The host attachment site appears to be a genomic island that is tied to insertion sequence (IS) activity that could facilitate mobility of a gene involved in the nitrogen-stress response. The homologous region and a secondary IS-element hot-spot in Synechococcus RS9917 are further evidence of IS-mediated genome evolution coincident with a probable relic prophage integration event. This siphovirus genome provides a glimpse into the biology of a deep-photic zone phage as well as the ocean cyanobacterial prophage and IS element �

Disinfection efficiency of peracetic acid, UV and ozone after enhanced primary treatment of municipal wastewater.

Science.gov (United States)

Gehr, Ronald; Wagner, Monika; Veerasubramanian, Priya; Payment, Pierre

2003-11-01

The City of Montreal Wastewater Treatment Plant uses enhanced physicochemical processes (ferric and/or alum coagulation) for suspended solids and phosphorus removal. The objective of this study was to assess the ability of peracetic acid (PAA), UV, or ozone to inactivate the indicator organisms fecal coliforms, Enterococci, MS-2 coliphage, or Clostridium perfringens in the effluent from this plant. PAA doses to reach the target fecal coliform level of 9000 CFU/100mL exceeded 6 mg/L; similar results were obtained for enterococci, and no inactivation of Clostridium perfringens was observed. However a 1-log reduction of MS-2 occurred at PAA doses of 1.5 mg/L and higher. It was expected that this effluent would have a high ozone demand, and would require relatively high UV fluences, because of relatively high effluent COD, iron and suspended solids concentrations, and low UV transmittance. This was confirmed herein. For UV, the inactivation curve for fecal coliforms showed the typical two-stage shape, with the target of 1000 CFU/100 mL (to account for photoreactivation) occurring in the asymptote zone at fluences >20 mJ/cm(2). In contrast, inactivation curves for MS-2 and Clostridium perfringens were linear. Clostridium perfringens was the most resistant organism. For ozone, inactivation was already observed before any residuals could be measured. The transferred ozone doses to reach target fecal coliform levels ( approximately 2-log reduction) were 30-50 mg/L. MS-2 was less resistant, but Clostridium perfringens was more resistant than fecal coliforms. The different behaviour of the four indicator organisms studied, depending on the disinfectant, suggests that a single indicator organism might not be appropriate. The required dose of any of the disinfectants is unlikely to be economically viable, and upstream changes to the plant will be needed.

Modelling the transport and decay processes of microbial tracers in a macro-tidal estuary.

Science.gov (United States)

Abu-Bakar, Amyrhul; Ahmadian, Reza; Falconer, Roger A

2017-10-15

The Loughor Estuary is a macro-tidal coastal basin, located along the Bristol Channel, in the South West of the U.K. The maximum spring tidal range in the estuary is up to 7.5 m, near Burry Port Harbour. This estuarine region can experience severe coastal flooding during high spring tides, including extreme flooding of the intertidal saltmarshes at Llanrhidian, as well as the lower industrial and residential areas at Llanelli and Gowerton. The water quality of this estuarine basin needs to comply with the designated standards for safe recreational bathing and shellfish harvesting industries. The waterbody however, potentially receives overloading of bacterial inputs that enter the estuarine system from both point and diffuse sources. Therefore, a microbial tracer study was carried out to get a better understanding of the faecal bacteria sources and to enable a hydro-environmental model to be refined and calibrated for both advection and dispersion transport. A two-dimensional hydro-environmental model has been refined and extended to predict the highest water level covering the intertidal floodplains of the Loughor Estuary. The validated hydrodynamic model for both water levels and currents, was included with the injected mass of microbial tracer, i.e. MS2 coliphage from upstream of the estuary, and modelled as a non-conservative tracer over several tidal cycles through the system. The calibration and validation of the transport and decay of microbial tracer was undertaken, by comparing the model results and the measured data at two different sampling locations. The refined model developed as a part of this study, was used to acquire a better understanding of the water quality processes and the potential sources of bacterial pollution in the estuary. Copyright © 2017 Elsevier Ltd. All rights reserved.

Chitosan Coagulation to Improve Microbial and Turbidity Removal by Ceramic Water Filtration for Household Drinking Water Treatment

Science.gov (United States)

Abebe, Lydia S.; Chen, Xinyu; Sobsey, Mark D.

2016-01-01

The use of porous ceramic filters is promoted globally for household water treatment, but these filters are ineffective in removing viruses from water. In order to increase virus removal, we combine a promising natural coagulant, chitosan, as a pretreatment for ceramic water filters (CWFs) and evaluate the performance of this dual barrier water treatment system. Chitosan is a non-toxic and biodegradable organic polymer derived by simple chemical treatments from chitin, a major source of which is the leftover shells of crustacean seafoods, such as shrimp, prawns, crabs, and lobsters. To determine the effectiveness of chitosan, model test water was contaminated with Escherichia coli K011 and coliphage MS2 as a model enteric bacterium and virus, respectively. Kaolinite clay was used to model turbidity. Coagulation effectiveness of three types of modified chitosans was determine at various doses ranging from 5 to 30 mg/L, followed by flocculation and sedimentation. The pre-treated supernatant water was then decanted into the CWF for further treatment by filtration. There were appreciable microbial removals by chitosan HCl, acetate, and lactate pretreatment followed by CWF treatment, with mean reductions (95% CI) between 4.7 (±1.56) and 7.5 (±0.02) log10 for Escherichia coli, and between 2.8 (±0.10) and 4.5 (±1.04) log10 for MS2. Turbidity reduction with chitosan treatment and filtration consistently resulted in turbidities turbidity standards of the US EPA and guidance by the World Health Organization (WHO). According to WHO health-based microbial removal targets for household water treatment technology, chitosan coagulation achieved health protective targets for both viruses and bacteria. Therefore, the results of this study support the use of chitosan to improve household drinking water filtration processes by increasing virus and bacteria reductions. PMID:26927152

Hydrogen exchange kinetics in a membrane protein determined by 15N NMR spectroscopy: Use of the INEPT [insensitive nucleus enhancement by polarization transfer] experiment to follow individual amides in detergent-solubilized M13 coat protein

International Nuclear Information System (INIS)

Henry, G.D.; Sykes, B.D.

1990-01-01

The coat protein of the filamentous coliphage M13 is a 50-residue polypeptide which spans the inner membrane of the Escherichia coli host upon infection. Amide hydrogen exchange kinetics have been used to probe the structure and dynamics of M13 coat protein which has been solubilized in sodium dodecyl sulfate (SDS) micelles. In a previous 1 H nuclear magnetic resonance (NMR) study, multiple exponential analysis of the unresolved amide proton envelope revealed the existence of two slow kinetic sets containing a total of about 30 protons. The slower set (15-20 amides) originates from the hydrophobic membrane-spanning region and exchanges at least 10 5 -fold slower than the unstructured, non-H-bonded model polypeptide poly(DL-alanine). Herein the authors use 15 N NMR spectroscopy of biosynthetically labeled coat protein to follow individual, assigned, slowly exchanging amides in or near the hydrophobic segment. The INEPT (insensitive nucleus enhancement by polarization transfer) experiments can be used to transfer magnetization to the 15 N nucleus from a coupled proton; when 15 N-labeled protonated protein is dissolved in 2 H 2 O, the INEPT signal disappears with time as the amide protons are replaced by solvent deuterons. Amide hydrogen exchange is catalyzed by both H + and OH - ions. The time-dependent exchange-out experiment is suitable for slow exchange rates (k ex ). The INEPT experiment was also adapted to measure some of the more rapidly exchanging amides in the coat protein using either saturation transfer from water or exchange effects on the polarization transfer step itself. The results of all of these experiments are consistent with previous models of the coat protein in which a stable segment extends from the hydrophobic membrane-spanning region through to the C-terminus, whereas the N-terminal region is undergoing more extensive dynamic fluctuations

Chitosan Coagulation to Improve Microbial and Turbidity Removal by Ceramic Water Filtration for Household Drinking Water Treatment

Directory of Open Access Journals (Sweden)

Lydia S. Abebe

2016-02-01

Full Text Available The use of porous ceramic filters is promoted globally for household water treatment, but these filters are ineffective in removing viruses from water. In order to increase virus removal, we combine a promising natural coagulant, chitosan, as a pretreatment for ceramic water filters (CWFs and evaluate the performance of this dual barrier water treatment system. Chitosan is a non-toxic and biodegradable organic polymer derived by simple chemical treatments from chitin, a major source of which is the leftover shells of crustacean seafoods, such as shrimp, prawns, crabs, and lobsters. To determine the effectiveness of chitosan, model test water was contaminated with Escherichia coli K011 and coliphage MS2 as a model enteric bacterium and virus, respectively. Kaolinite clay was used to model turbidity. Coagulation effectiveness of three types of modified chitosans was determine at various doses ranging from 5 to 30 mg/L, followed by flocculation and sedimentation. The pre-treated supernatant water was then decanted into the CWF for further treatment by filtration. There were appreciable microbial removals by chitosan HCl, acetate, and lactate pretreatment followed by CWF treatment, with mean reductions (95% CI between 4.7 (±1.56 and 7.5 (±0.02 log10 for Escherichia coli, and between 2.8 (±0.10 and 4.5 (±1.04 log10 for MS2. Turbidity reduction with chitosan treatment and filtration consistently resulted in turbidities < 1 NTU, which meet turbidity standards of the US EPA and guidance by the World Health Organization (WHO. According to WHO health-based microbial removal targets for household water treatment technology, chitosan coagulation achieved health protective targets for both viruses and bacteria. Therefore, the results of this study support the use of chitosan to improve household drinking water filtration processes by increasing virus and bacteria reductions.

Removal of phages and viral pathogens in a full-scale MBR: Implications for wastewater reuse and potable water.

Science.gov (United States)

Purnell, Sarah; Ebdon, James; Buck, Austen; Tupper, Martyn; Taylor, Huw

2016-09-01

The aim of this study was to demonstrate how seasonal variability in the removal efficacy of enteric viral pathogens from an MBR-based water recycling system might affect risks to human health if the treated product were to be used for the augmentation of potable water supplies. Samples were taken over a twelve month period (March 2014-February 2015), from nine locations throughout a water recycling plant situated in East London and tested for faecal indicator bacteria (thermotolerant coliforms, intestinal enterococci n = 108), phages (somatic coliphage, F-specific RNA phage and Bacteroides phage (GB-124) n = 108), pathogenic viruses (adenovirus, hepatitis A, norovirus GI/GII n = 48) and a range of physico-chemical parameters (suspended solids, DO, BOD, COD). Thermotolerant coliforms and intestinal enterococci were removed effectively by the water recycling plant throughout the study period. Significant mean log reductions of 3.9-5.6 were also observed for all three phage groups monitored. Concentrations of bacteria and phages did not vary significantly according to season (P < 0.05; Kruskal-Wallis), though recorded levels of norovirus (GI) were significantly higher during autumn/winter months (P = 0.027; Kruskal-Wallis). Log reduction values for norovirus and adenovirus following MBR treatment were 2.3 and 4.4, respectively. However, both adenovirus and norovirus were detected at low levels (2000 and 3240 gene copies/L, respectively) post chlorination in single samples. Whilst phage concentrations did correlate with viral pathogens, the results of this study suggest that phages may not be suitable surrogates, as viral pathogen concentrations varied to a greater degree seasonally than did the phage indicators and were detected on a number of occasions on which phages were not detected (false negative sample results). Copyright © 2016 Elsevier Ltd. All rights reserved.

Bacteriophage removal in a full-scale membrane bioreactor (MBR) - Implications for wastewater reuse.

Science.gov (United States)

Purnell, Sarah; Ebdon, James; Buck, Austen; Tupper, Martyn; Taylor, Huw

2015-04-15

The aim of this study was to assess the potential removal efficacy of viruses in a full-scale membrane bioreactor (MBR) wastewater reuse system, using a range of indigenous and 'spiked' bacteriophages (phages) of known size and morphology. Samples were taken each week for three months from nine locations at each treatment stage of the water recycling plant (WRP) and tested for a range of microbiological parameters (n = 135). Mean levels of faecal coliforms were reduced to 0.3 CFU/100 ml in the MBR product and were undetected in samples taken after the chlorination stage. A relatively large reduction (5.3 log) in somatic coliphages was also observed following MBR treatment. However, F-specific and human-specific (GB124) phages were less abundant at all stages, and demonstrated log reductions post-MBR of 3.5 and 3.8, respectively. In 'spiking' experiments, suspended 'spiked' phages (MS2 and B-14) displayed post-MBR log reductions of 2.25 and 2.30, respectively. The removal of these suspended phages, which are smaller than the membrane pore size (0.04 μm), also highlights the possible role of the membrane biofilm as an effective additional barrier to virus transmission. The findings from this study of a full-scale MBR system demonstrate that the enumeration of several phage groups may offer a practical and conservative way of assessing the ability of MBR to remove enteric viruses of human health significance. They also suggest that phage removal in MBR systems may be highly variable and may be closely related on the one hand to both the size and morphology of the viruses and, on the other, to whether or not they are attached to solids. Copyright © 2015 Elsevier Ltd. All rights reserved.

UV irradiation of Shigella Dysenteriae induced the transformation and excision of a presumed integrated lysogenic prophage Shd-4L10 into a lytic phase

International Nuclear Information System (INIS)

Rodrigues, F. K.; Addy, B.; Armah, G.; Fobil, J.; Steiner-Asiedu, M.; Efavi, J.

2012-01-01

Repeated exposures of Shigella dysenteriae strain A to ultra-violet radiation (253.7 nm) with intervening outgrowth of survivors gave rise to clear bacteriophage plaques. Isolation, propagation and partial purification of the new Shd-4LI0 phages showed that they are similar in morphology to the Myxobacteriaphage Mx-4 described earlier. The new phages retained the general characteristics of S. dystenteriae phageShd-4L3, including serological properties and phage typing. It is suggested that ultra-violet irradiation may have played a role in the transformation and excision of the presumed lysogen of S. dysenteriaestrain A into a lytic phase. PhageShd-4LI0 was subsequently partially characterized. It has a density of 1.61, a DNA: protein ratio of 0.42 and thus a cryptogram of D/2:54.3/32.5:X/X: B/O. The phage was further characterised by fractionation of its protein using SDS-polyacrilamide gel electrophoresis. DNA extracted from phages was hydrolysed with restriction endonuclease R., EcoR1. The restriction fragments were catalogued and their apparent molecular weights calculated from electrophoresis gels calibrated with fragments from DNA of coliphageλ λ. From the total fragments obtained with nuclease R., EcoR1, the apparent minimum molecular weight of phage Shd-4LI0DNA was found to be 54.3 x 10 6 Daltons. The molecular weight of the phage DNA was also calculated from measurements of contour length of purified DNA samples, using the formula MW = 1.97 x 10 10 1/(magnification), where 1 is the measured length of DNA in centimetres). The very close relatedness with phage Shd-4L3 was confirmed by these techniques. (au)

Ballast water: a review of the impact on the world public health

Directory of Open Access Journals (Sweden)

CK Takahashi

2008-01-01

Full Text Available Since the nineteenth century ships have been using ballast water (BW for safety, stability, propulsion and maneuverability, as well as to redress loss of fuel weight and water consumption, and to maintain structural stress at acceptable levels. Ballast water has been spreading many non-native species around the globe, but little is known about the extent and potential significance of ship-mediated transfer of microorganisms. The global movements of ballast water by ships create a long-distance dispersal mechanism for human pathogens that may be important in the worldwide distribution of microorganisms, as well as for the epidemiology of waterborne diseases. Only a few studies have been carried out on this subject, most of them involving ballast water containing crustacean larvae and phytoplankton. Specialized microbiological studies on these waters are necessary to avoid a repeat of what happened in 1991, when epidemic cholera was reported in Peru and rapidly spread through Latin America and Mexico. In July of 1992, Vibrio cholerae was found in the USA and the Food and Drug Administration (FDA determined that it came from ballast water of ships whose last port of call was in South America. In Brazil, just a few studies about the subject have been performed. An exploratory study by the Brazilian National Health Surveillance Agency (Agência Nacional de Vigilância Sanitária - ANVISA found in ballast water different microorganisms, such as fecal coliforms, Escherichia coli, Enterococcus faecalis, Clostridium perfringens, coliphages, Vibrio cholerae O1 and Vibrio cholerae non-O1. Until now, Brazil has been focusing only on organisms transported to its territory from other countries by ballast water, to avoid their establishment and dissemination in Brazilian areas. Studies that can assess the probability that water ballast carries pathogenic microorganisms are extremely important, as is the examination of ships that arrive in the country

Study of genetic effects of high energy radiations with different ionizing capacities on extracellular phages.

Science.gov (United States)

Bresler, S E; Kalinin, V L; Kopylova, Y U; Krivisky, A S; Rybchin, V N; Shelegedin, V N

1975-07-01

The inactivating and mutagenic action of high-energy radiations with different ionizing capacities (gamma-rays, protons, alpha-particles and accelerated ions of 12C and 20Ne) was studied by using coliphages lambda11 and SD as subjects. In particular the role of irradiation conditions (broth suspension, pure buffer, dry samples) and of the host functions recA, exrA and polA was investigated. The dose-response curve of induced mutagenesis was studied by measuring the yield of vir mutants in lambda11 and plaque mutants in SD. The following results were obtained. (1) The inactivation kinetics of phages under the action of gamma-rays and protons was first order to a survival of 10(-7). Heavy ions also showed exponential inactivation kinetics to a survival of 10(-4). At higher doses of 20Ne ion bombardment some deviation from one-hit kinetics was observed. For dry samples of phages the dimensions of targets for all types of radiation were approximately proportional to the molecular weights of phage DNA's. For densely ionizing radiation (heavy ions) the inactivating action was 3-5 times weaker than for gamma-rays and protons. (2) Mutagenesis was observed for all types of radiation, but heavy ions were 1-5-2 times less efficient than gamma-rays. For both phages studied the dose-response curve of mutagenesis was non-linear. The dependence on the dose was near to parabolic for lambda11. For SD a plateau or maximum of mutagenesis was observed for the relative number of mutants at a survival of about 10(-4). (3) Host-cell functions recA and exrA were practically indifferent for survival of gamma-irradiated phage lambda11, but indispensable for mutagenesis. Mutation recAI3 abolished induced vir mutations totally and exrA- reduced them significantly. The absence of the function polA had a considerable influence on phage survival, but no effect on vir mutation yield (if compared at the same survival level). (4) In conditions of indirect action of gamma-rays no vir mutations were

A review of virus removal in wastewater treatment pond systems.

Science.gov (United States)

Verbyla, Matthew E; Mihelcic, James R

2015-03-15

Wastewater treatment ponds (lagoons) are one of the most common types of technologies used for wastewater management worldwide, especially in small cities and towns. They are particularly well-suited for systems where the effluent is reused for irrigation. However, the efficiency of virus removal in wastewater treatment pond systems is not very well understood. The main objective of this paper is to critically review the major findings related to virus removal in wastewater treatment pond systems and to statistically analyze results reported in the literature from field studies on virus removal in these systems. A comprehensive analysis of virus removal reported in the literature from 71 different wastewater treatment pond systems reveals only a weak to moderate correlation of virus removal with theoretical hydraulic retention time. On average, one log10 reduction of viruses was achieved for every 14.5-20.9 days of retention, but the 95th percentile value of the data analyzed was 54 days. The mechanisms responsible for virus removal in wastewater treatment ponds were also reviewed. One recent finding is that sedimentation may not be a significant virus removal mechanism in some wastewater ponds. Recent research has also revealed that direct and indirect sunlight-mediated mechanisms are not only dependent on pond water chemistry and optics, but also on the characteristics of the virus and its genome. MS2 coliphage is considered to be the best surrogate for studying sunlight disinfection in ponds. The interaction of viruses with particles, with other microorganisms, and with macroinvertebrates in wastewater treatment ponds has not been extensively studied. It is also unclear whether virus internalization by higher trophic-level organisms has a protective or a detrimental effect on virus viability and transport in pond systems. Similarly, the impact of virus-particle associations on sunlight disinfection in ponds is not well understood. Future research should focus on

Differential MS2 Interaction with Food Contact Surfaces Determined by Atomic Force Microscopy and Virus Recovery.

Science.gov (United States)

Shim, J; Stewart, D S; Nikolov, A D; Wasan, D T; Wang, R; Yan, R; Shieh, Y C

2017-12-15

Enteric viruses are recognized as major etiologies of U.S. foodborne infections. These viruses are easily transmitted via food contact surfaces. Understanding virus interactions with surfaces may facilitate the development of improved means for their removal, thus reducing transmission. Using MS2 coliphage as a virus surrogate, the strength of virus adhesion to common food processing and preparation surfaces of polyvinyl chloride (PVC) and glass was assessed by atomic force microscopy (AFM) and virus recovery assays. The interaction forces of MS2 with various surfaces were measured from adhesion peaks in force-distance curves registered using a spherical bead probe preconjugated with MS2 particles. MS2 in phosphate-buffered saline (PBS) demonstrated approximately 5 times less adhesion force to glass (0.54 nN) than to PVC (2.87 nN) ( P force for PVC (∼0 nN) and consistently increased virus recovery by 19%. With direct and indirect evidence of virus adhesion, this study illustrated a two-way assessment of virus adhesion for the initial evaluation of potential means to mitigate virus adhesion to food contact surfaces. IMPORTANCE The spread of foodborne viruses is likely associated with their adhesive nature. Virus attachment on food contact surfaces has been evaluated by quantitating virus recoveries from inoculated surfaces. This study aimed to evaluate the microenvironment in which nanometer-sized viruses interact with food contact surfaces and to compare the virus adhesion differences using AFM. The virus surrogate MS2 demonstrated less adhesion force to glass than to PVC via AFM, with the force-contributing factors including the intrinsic nature and the topography of the contact surfaces. This adhesion finding is consistent with the virus recoveries, which were determined indirectly. Greater numbers of viruses were recovered from glass than from PVC, after application at the same levels. The stronger MS2 adhesion onto PVC could be interrupted by incorporating a

Food and water security issues in Russia II: water security in general population of Russian Arctic, Siberia and Far East, 2000-2011.

Science.gov (United States)

Dudarev, Alexey A; Dushkina, Eugenia V; Sladkova, Yuliya N; Alloyarov, Pavel R; Chupakhin, Valery S; Dorofeyev, Vitaliy M; Kolesnikova, Tatjana A; Fridman, Kirill B; Evengard, Birgitta; Nilsson, Lena M

2013-01-01

Poor state of water supply systems, shortage of water purification facilities and disinfection systems, low quality of drinking water generally in Russia and particularly in the regions of the Russian Arctic, Siberia and Far East have been defined in the literature. However, no standard protocol of water security assessment has been used in the majority of studies. Uniform water security indicators collected from Russian official statistical sources for the period 2000-2011 were used for comparison for 18 selected regions in the Russian Arctic, Siberia and Far East. The following indicators of water security were analyzed: water consumption, chemical and biological contamination of water reservoirs of Categories I and II of water sources (centralized--underground and surface, and non-centralized) and of drinking water. Water consumption in selected regions fluctuated from 125 to 340 L/person/day. Centralized water sources (both underground and surface sources) are highly contaminated by chemicals (up to 40-80%) and biological agents (up to 55% in some regions), mainly due to surface water sources. Underground water sources show relatively low levels of biological contamination, while chemical contamination is high due to additional water contamination during water treatment and transportation in pipelines. Non-centralized water sources are highly contaminated (both chemically and biologically) in 32-90% of samples analyzed. Very high levels of chemical contamination of drinking water (up to 51%) were detected in many regions, mainly in the north-western part of the Russian Arctic. Biological contamination of drinking water was generally much lower (2.5-12%) everywhere except Evenki AO (27%), and general and thermotolerant coliform bacteria predominated in drinking water samples from all regions (up to 17.5 and 12.5%, correspondingly). The presence of other agents was much lower: Coliphages--0.2-2.7%, Clostridia spores, Giardia cysts, pathogenic bacteria, Rotavirus

Food and water security issues in Russia II: Water security in general population of Russian Arctic, Siberia and Far East, 2000–2011

Directory of Open Access Journals (Sweden)

Alexey A. Dudarev

2013-12-01

Full Text Available Background . Poor state of water supply systems, shortage of water purification facilities and disinfection systems, low quality of drinking water generally in Russia and particularly in the regions of the Russian Arctic, Siberia and Far East have been defined in the literature. However, no standard protocol of water security assessment has been used in the majority of studies. Study design and methods . Uniform water security indicators collected from Russian official statistical sources for the period 2000–2011 were used for comparison for 18 selected regions in the Russian Arctic, Siberia and Far East. The following indicators of water security were analyzed: water consumption, chemical and biological contamination of water reservoirs of Categories I and II of water sources (centralized – underground and surface, and non-centralized and of drinking water. Results . Water consumption in selected regions fluctuated from 125 to 340 L/person/day. Centralized water sources (both underground and surface sources are highly contaminated by chemicals (up to 40–80% and biological agents (up to 55% in some regions, mainly due to surface water sources. Underground water sources show relatively low levels of biological contamination, while chemical contamination is high due to additional water contamination during water treatment and transportation in pipelines. Non-centralized water sources are highly contaminated (both chemically and biologically in 32–90% of samples analyzed. Very high levels of chemical contamination of drinking water (up to 51% were detected in many regions, mainly in the north-western part of the Russian Arctic. Biological contamination of drinking water was generally much lower (2.5–12% everywhere except Evenki AO (27%, and general and thermotolerant coliform bacteria predominated in drinking water samples from all regions (up to 17.5 and 12.5%, correspondingly. The presence of other agents was much lower: Coliphages �

Food and water security issues in Russia II: Water security in general population of Russian Arctic, Siberia and Far East, 2000–2011

Science.gov (United States)

Dudarev, Alexey A.; Dushkina, Eugenia V.; Sladkova, Yuliya N.; Alloyarov, Pavel R.; Chupakhin, Valery S.; Dorofeyev, Vitaliy M.; Kolesnikova, Tatjana A.; Fridman, Kirill B.; Evengard, Birgitta; Nilsson, Lena M.

2013-01-01

Background Poor state of water supply systems, shortage of water purification facilities and disinfection systems, low quality of drinking water generally in Russia and particularly in the regions of the Russian Arctic, Siberia and Far East have been defined in the literature. However, no standard protocol of water security assessment has been used in the majority of studies. Study design and methods Uniform water security indicators collected from Russian official statistical sources for the period 2000–2011 were used for comparison for 18 selected regions in the Russian Arctic, Siberia and Far East. The following indicators of water security were analyzed: water consumption, chemical and biological contamination of water reservoirs of Categories I and II of water sources (centralized – underground and surface, and non-centralized) and of drinking water. Results Water consumption in selected regions fluctuated from 125 to 340 L/person/day. Centralized water sources (both underground and surface sources) are highly contaminated by chemicals (up to 40–80%) and biological agents (up to 55% in some regions), mainly due to surface water sources. Underground water sources show relatively low levels of biological contamination, while chemical contamination is high due to additional water contamination during water treatment and transportation in pipelines. Non-centralized water sources are highly contaminated (both chemically and biologically) in 32–90% of samples analyzed. Very high levels of chemical contamination of drinking water (up to 51%) were detected in many regions, mainly in the north-western part of the Russian Arctic. Biological contamination of drinking water was generally much lower (2.5–12%) everywhere except Evenki AO (27%), and general and thermotolerant coliform bacteria predominated in drinking water samples from all regions (up to 17.5 and 12.5%, correspondingly). The presence of other agents was much lower: Coliphages – 0.2–2

The use of geoinformatic data and spatial analysis to predict faecal pollution during extreme precipitation events

Science.gov (United States)

Ward, Ray; Purnell, Sarah; Ebdon, James; Nnane, Daniel; Taylor, Huw

2013-04-01

The Water Framework Directive (WFD) regulates surface water quality standards in the European Union (EU). The Directive call for the identification and management of point and diffuse sources of pollution and requires the establishment of a 'programme of measures' for identified river basin districts, in order to achieve a "good status" by 2015. The hygienic quality of water is normally monitored using faecal indicator organisms (FIO), such as Escherichia coli, which indicate a potential risk to public health from human waterborne pathogens. Environmental factors influence the transmission of these pathogens and indicator organisms, and statistically significant relationships have been found between rainfall and outbreaks of waterborne disease. Climate change has been predicted to lead to an increase in severe weather events in many parts of Europe, including an increase in the frequency of extreme rainfall events. This in turn is likely to lead to an increase in incidents of human waterborne disease in Europe, unless measures are taken to predict and mitigate for such events. This study investigates a variety of environmental factors that influence the concentration of FIO in surface waters receiving faecal contamination from a variety of sources. Levels of FIO, including Escherichia coli, intestinal enterococci, somatic coliphage and GB124 (a human-specific microbial source tracking marker), were monitored in the Sussex Ouse catchment in Southeast England over a period of 26 months. These data were combined with geoinformatic environmental data within a GIS to map faecal contamination within the river. Previously, precipitation and soil erosion have been identified as major factors that can influence the concentration of these faecal markers, and studies have shown that slope, soil type and vegetation influence both the mechanisms and the rate by which erosion occurs in river catchments. Of the environmental variables studied, extreme precipitation was found to