Virological Quality Of Water Research Articles

Virological and bacteriological quality of drinking water in Ethiopia

Background: Since unsafe water is responsible for serious illness, deaths due to highest burdens of diseases and greatest economic failure, monitoring the quality of water is essential. Water Quality monitoring is assessed widely using different indicators. Bacterial and viral indicators provide more complete picture of water quality. Virological quality of water hasn’t been assessed in most countries including Ethiopia. The use of E. coli CB390 minimizes resource and time to perform the tests in simultaneous detection of somatic and male-specific coliphages. Methods & Materials: A cross sectional study was conducted on 218 drinking waters samples collected from various regions of Ethiopia from February to June 2016 to assess water quality using coliphages by the help of CB390 E. coli host, plaque assay; Multiple tube fermentation method for coliforms and pour plate technique for counting heterotrophic bacteria at Ethiopian Public Health Institute. The data were analyzed using SPSS 20. Results: Heterotrophic bacteria, total and thermotolerant coliforms, E. coli and phages were detected in 72.9%, 51.8%, 38.5%, 23.9% and 2.3% of the total samples respectively. Heterotrophic plate count greater than 100 CFU/ml were noted in 41 (18.8%) samples and detections of total and thermotolerant coliforms and E. coli in 38 (17.4%), 24 (11.0%) and 10 (4.6%) samples respectively and no detection of phages in chlorinated waters. While, Heterotrophic plate count greater than 100 CFU/mL were observed in 100 (45.9%) samples and detections of total and thermotolerant coliforms, E. coli and coliphages in 75 (34.4%), 60 (27.5%), 42 (19.3%) and 5 (2.3%) samples respectively for untreated waters. Conclusion: Majority of the waters contained indicators above standard limits. This indicates that the sources are contaminated with environmental and fecal contaminants signifying poor quality and it is a potential threat to human and animals health. Hence regular water monitoring using various indicators should be a priority agenda by all stake holders.

The impact of anthropogenic pressure on the virological quality of water from the Tiber River, Italy.

To the best of our knowledge, this study constitutes the first attempt to assess the occurrence of enteric viruses in river waters, in areas differentially influenced by anthropogenic pressure. Enteric viruses (enterovirus, norovirus, adenovirus, rotavirus, hepatitis A and E viruses, and bocavirus) were widespread in the industrial and urban areas, and were less frequently detected in the agricultural area. Interestingly, human bocavirus was the most frequently detected virus, outnumbering even adenoviruses, known to be widespread in water environments. The widespread presence of bocavirus in surface waters suggests that a potential role of water in its transmission should not be excluded.

Male-specific RNA coliphages detected by plaque assay and RT-PCR in tropical river waters and animal fecal matter

Male-specific RNA coliphages (FRNA) have been recommended as indicators of fecal contamination and of the virological quality of water. In this study, 16 river water and 183 animal fecal samples were examined for the presence of FRNA coliphages by a plaque assay using Salmonella typhimurium WG49 and WG25 to differentiate between male-specific and somatic phages, a RNase spot test to differentiate between DNA and RNA phages and a reverse transcriptase-polymerase chain reaction (RT-PCR) for the specific identification of FRNA phages. The overall recovery rate for F-specific coliphages was 8.0%. (4.4% from animal fecal matter and 50% from river water samples). Plaque counts were generally low (< 6×102 pfu per g feces or ml water), with FRNA (6.5%) and Male-specific DNA coliphages (FDNA) (7.0%) phages occurring at almost equal frequencies. The RT-PCR was positive in all FRNA plaques and was able to identify FRNA phages in mixed populations of FRNA, FDNA and somatic phages.