Virus levels in river waters

Walter, R.; Macht, Wolfgang; Dürkop, J; Hecht, R.; Hornig, U.; Schulze, Peter

doi:10.1016/0043-1354(89)90036-5

Cited by 13 publications

(6 citation statements)

References 5 publications

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“…It has been reported that various river pollutants such as oxygen, nitrogen, salt and organic compounds, have an affect on the survival and distribution of viruses (12,21). However, it is very difficult to determine whether the quality of river water influenced the viral contamination observed in this study.…”

Section: Discussioncontrasting

confidence: 39%

Seasonal Distribution of Adenoviruses, Enteroviruses and Reoviruses in Urban River Water

Tani

Dohi

Kurumatani

et al. 1995

Microbiology and Immunology

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In the 63-month period from January 1988 to March 1993, monthly levels of adenoviruses, enteroviruses (coxsackie B, polio, echo) and reoviruses in the urban river water in Nara Prefecture, Japan were in the range 0-25, 0-190 and 0-325, plaque forming units per liter (PFU/liter), and the average levels were 2.4, 40.6 and 56.2 PFU/liter, respectively. The peak reovirus level was found in winter during the cold weather months (Nov. to Mar.). The peak enterovirus level was found in summer (May to Sept.) but continued to be found in autumn-winter (Oct. to Jan.) from 1991 to 1993. The levels of adenoviruses were low throughout all 5 years, as compared to those of reoviruses and enteroviruses. Polioviruses were isolated following the administration of vaccine. Although a changing pattern of serotype prevalence was seen with the coxsackie B viruses and echoviruses from 1988 to 1993, this is not so for polioviruses, which remained almost unchanged for the five-year period. Adenoviruses were isolated throughout all five years, though in small numbers. Reoviruses were isolated most frequently throughout five years.

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Section: Discussioncontrasting

confidence: 39%

Seasonal Distribution of Adenoviruses, Enteroviruses and Reoviruses in Urban River Water

Tani

Dohi

Kurumatani

et al. 1995

Microbiology and Immunology

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“…Previous studies have reported phage abundance in rivers and ocean waters to range from 10 3 to 10 8 particles ml −1 (Bergh et al ., 1989; Hennes & Suttle, 1995; Paul et al ., 1991; Walter et al ., 1989). We wished to validate the presence of significant phage populations at our freshwater-lake field site, a small (5 ha) oligotrophic natural lake.…”

Section: Resultsmentioning

confidence: 99%

“…Recent studies have documented extensive reservoirs of viral particles in natural ecosystems (Bergh et al ., 1989; Bratbak & Heldal, 1993; Hennes & Suttle, 1995; Paul et al ., 1991; Proctor & Fuhrman, 1990; Walter et al ., 1989). However, current knowledge of microbial and viral population dynamics does not support the production or the maintenance of large viral populations within natural environments.…”

Section: Introductionmentioning

confidence: 99%

The role of pseudolysogeny in bacteriophage-host interactions in a natural freshwater environment

1997

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Bacteriophages occur in high numbers in environmental ecosystems and are thus significant mediators of microbial survival and activities. However, interactions between microbial populations and phages in situ have been largely ignored. Current understanding of the process relies on studies performed with well-fed, laboratory-grown host bacteria. The purpose of the experiments reported here was to determine bacteriophage-host interactions under environmentally relevant conditions of nutrient limitation. These studies have revealed the importance of a phenomenon called pseudolysogeny in the maintenance of viral genetic material for extended periods of time in natural ecosystems. Pseudolysogeny is a form of phage-host cell interaction in which the nucleic acid of the phage resides within its starved host in an unstable, inactive state. It is hypothesized that pseudolysogeny occurs due to the cell's highly starved condition. In such cells, there is insufficient energy available for the phage to initiate genetic expression leading to either a true temperate response or to the lytic response. However, upon nutrient addition, the pseudolysogenic state is resolved, resulting in either the establishment of true lysogeny or the initiation of the lytic production of progeny virions. The pseudolysogenic state may explain the long-term survival of viruses in unfavourable environments in which the infective half-life of their virions is relatively short.

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“…This led to investigations of the virological contamination in different riverine systems. Walter et al (1989), for example, found a close connection between a sewage index and the determined virus levels. From the lower reach of the Danube River, Walter et al (1990) reported on a pronounced virological risk in connection with producing drinking water.…”

Section: Inroductionmentioning

confidence: 90%

Viruses, bacteria and suspended particles in a backwater and main channel site of the Danube (Austria)

Peduzzi

Luef

2008

Aquat. Sci.

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A short overview of currently available studies on the ecology of viruses in running waters is provided. Additionally, a survey was conducted on the dynamics of both viruses and bacteria in an isolated floodplain segment of the Danube River and in the main channel near Vienna (Austria) during the hydrologically most dynamic phase (spring -summer). The study evaluates the differences between the main channel and the floodplain segment for suspended particle abundance and quality in relation to bacterial and viral parameters; both free-living forms and those attached to particles are examined. The hydrological disconnection of these two contrasting sampling sites influenced particle abundance and quality as well as the distribution of free-living vs. attached bacteria and viruses. The per-cell activity of bacteria attached to particles was significantly higher than that of the free-living fraction, particularly in the isolated water body. The abundance of bacteria and viruses on particles depended on particle quality (size). In the main channel, bacteria were significantly more abundant on surfaces (per mm 2 ) of suspended matter > 5 μm (aggregates with organic constituents) compared to particles < 5 μm (mostly mineral grains). In the isolated water body, both bacteria and viruses were more abundant on the larger particles/ aggregates. Data from both locations revealed a positive correlation between abundance of particles > 5μm and attached viruses; free-living viruses were less abundant at high > 5μm particle loads. Only in the isolated floodplain section was viral abundance positively influenced by elevated per-cell productivity of potential host bacteria. The results demonstrate that system variability on a relatively small topographical scale (within a river-floodplain system) has consequences for microbial life, including viruses. KeywordsRiver-floodplain; seston; bacterial activity; virus ecology InroductionFollowing the discovery of high numbers of viruses in aquatic environments (now considered the most abundant biological entities in natural waters; Bergh et al., 1989), it soon was observed that this virioplankton is significantly linked to bacterio-and phytoplankton (Proctor and Fuhrman, 1990;Suttle et al., 1990). Since viruses infect all members of the microbial food web, they must be viewed as significant biological agents in microbial processes (for review see Wommack and Colwell, 2000;Weinbauer, 2004). Moreover, viral abundance is generally one to two orders of magnitude higher than that of bacterioplankton. Interestingly, there are indications that freshwater systems might differ from marine habitats regarding viral abundance and the ratio of viral to bacterial numbers (Maranger and Bird, 1995;Farnell-Jackson and Ward, 2003). Further surprising is that, although viruses play a significant role in marine and lake waters, many related aspects are largely ignored in research on the functioning of river systems.For many years the presence of viruses in river water has been a significant public ...

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Virus levels in river waters

Cited by 13 publications

References 5 publications

Seasonal Distribution of Adenoviruses, Enteroviruses and Reoviruses in Urban River Water

Seasonal Distribution of Adenoviruses, Enteroviruses and Reoviruses in Urban River Water

The role of pseudolysogeny in bacteriophage-host interactions in a natural freshwater environment

Viruses, bacteria and suspended particles in a backwater and main channel site of the Danube (Austria)

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