Detection of enteroviruses in untreated and treated drinking water supplies in South Africa

2005 ◽  
Vol 39 (11) ◽  
pp. 2253-2258 ◽  
Author(s):  
M.M. Ehlers ◽  
W.O.K. Grabow ◽  
D.N. Pavlov
Keyword(s):  
South Africa ◽  
Drinking Water ◽  
Water Supplies ◽  
Treated Drinking Water

Prevalence of human adenoviruses in raw and treated water

2004 ◽  
Vol 50 (1) ◽  
pp. 39-43 ◽  
Author(s):  
J. van Heerden ◽  
M.M. Ehlers ◽  
W.B. van Zyl ◽  
W.O.K. Grabow
Keyword(s):  
South Africa ◽  
Drinking Water ◽  
Clinical Importance ◽  
Molecular Techniques ◽  
International Standards ◽  
Water Supplies ◽  
Potential Health ◽  
Human Adenoviruses ◽  
One Year ◽  
Treated Drinking Water

Human adenoviruses (HAds), of which there are 51 antigenic types, are associated aetiologically with gastrointestinal, respiratory, urinary tract and eye infections. The clinical importance of HAds and the potential health risks constituted by HAds in water environments are widely recognised. This study was conducted to assess the use of an optimised integrated cell culture molecular-based technique to determine the prevalence of HAds in raw and treated drinking-water supplies in South Africa. Selected supplies were monitored weekly for the presence of adenoviruses over a one-year period (July 2001 to June 2002). Drinking-water supplies were derived from acceptable quality surface water sources using treatment processes that conformed to international standards for the production of safe drinking water. Adenoviruses were detected by amplification in cell cultures, followed by amplifying the extracted nucleic acids using molecular techniques (nested PCR). HAds were detected in 29.8% (59/198) of the treated drinking water, 16% (8/50) of dam water and 44% (22/50) of river-water samples tested. The results of this study confirmed the presence of HAds in some raw and treated drinking water supplies in South Africa.

Suitability of the H2S method for testing untreated and chlorinated water supplies

2001 ◽  
Vol 44 (6) ◽  
pp. 119-126 ◽  
Author(s):  
J. Nair ◽  
R. Gibbs ◽  
K. Mathew ◽  
G. E. Ho
Keyword(s):  
Drinking Water ◽  
Water Samples ◽  
False Negative ◽  
Total Coliform ◽  
Domestic Water ◽  
Salmonella Spp ◽  
Water Supplies ◽  
Good Test ◽  
Treated Drinking Water ◽  
Positive Results

Rainwater, borewater and catchment water are used for domestic water supply purposes with or without treatment in remote areas around the world. These places seldom have any facilities for routine testing of their drinking water. A simple on-site testing method is highly required in such areas. The H2S method has been tested for treated drinking water and was found to have a good correlation with the standard methods. The present study was aimed at assessing the suitability of the H2S method for testing different sources of drinking water. Since these types of water may contain H2S producing bacteria not of faecal origin the occurrence of false results in this method cannot be overruled. Therefore it was worthwhile to study whether the positive results are true positive results and what percentage of false positive and false negative results could be expected while using this test for routine analysis of water samples. Results were compared with the results using standard procedures for testing total coliforms, Escherichia coli and Salmonella spp. The present experiment analysed 121 rainwater samples, 17 borewater samples, 41 catchment water samples and 74 remote Aboriginal community water samples. Rainwater, borewater and catchment water samples gave true results of 78.5%, 82.3% and 80.5% respectively while the treated and untreated community samples gave true results of 93.7 and 84.6% respectively. It was concluded that in the developing countries where the acceptable level of total coliform is <10 MPN, the H2S method would be a good test to identify microbial contamination. In other regions, the H2S method could be used as a screening test for drinking water supplies.

Enumeration of Sulphite-Reducing Clostridia from Potable Water Supplies

1993 ◽  
Vol 27 (3-4) ◽  
pp. 279-282 ◽  
Author(s):  
D. P. Sartory ◽  
A. M. Pritchard ◽  
P. Holmes
Keyword(s):  
Heat Treatment ◽  
Drinking Water ◽  
River Water ◽  
Water Samples ◽  
Potable Water ◽  
Egg Yolk ◽  
Sewage Effluent ◽  
Water Supplies ◽  
System Integrity ◽  
Treated Drinking Water

The enumeration of sulphite-reducing Clostridia from water upon egg yolk-free tryptose-sulphite-cycloserine agar (TSC) was evaluated against the standard UK method of enumeration upon membrane-clostridial agar (MCA), with or without heat treatment of the sample. Using 280 samples of treated drinking water, raw groundwater, river water and sewage effluent, the recoveries of presumptive sulphite-reducing Clostridia were significantly higher on TSC than on MCA (both incubated at .37°C for 48 h), particularly from potable water samples where the system integrity had been breached. Clostridia were isolated from 26 of the 224 groundwater and drinking water samples, on 25 occasions with TSC but on only 3 occasions with MCA. From river water and sewage effluent samples, background growth was higher on TSC. Of 85 isolates from TSC, 92.9% were confirmed as Clostridia, whilst only 56.5% of 23 isolates from MCA confirmed, the remaining being Gram-positive rods and cocci and Gram-negative rods. Heat treatment of samples to 70°C for ten minutes prior to filtration did not affect counts on MCA, but significantly reduced both Clostridia and background counts on TSC. Clostridia isolated from compromised treated water supplies include Cloistridium perfringens, C. bgratii, C. difficile, C. limosum and C. subtgrminale.

Assessment of the risk of infection associated with Coxsackie B viruses in drinking water

2002 ◽  
Vol 2 (3) ◽  
pp. 1-8 ◽  
Author(s):  
J.C. Vivier ◽  
M.M. Ehlers ◽  
W.O.K. Grabow ◽  
A.H. Havelaar
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Clinical Manifestations ◽  
Upper Respiratory Tract ◽  
Risk Of Infection ◽  
Water Supplies ◽  
Treatment Unit ◽  
Coxsackie B Viruses ◽  
Treated Drinking Water ◽  
Coxsackie B

The risk of infection constituted by enteroviruses detected in drinking water supplies analysed in this study were assessed. Coxsackie B viruses (CBV) were used as a model in these assessments. A high proportion of Coxsackie B virus infections are asymptomatic. However, clinical manifestations may range from mild, undifferentiated febrile illness or upper respiratory tract infection to a severe, systemic and sometimes fatal disease of sensitive populations. Dose-response studies suggested that an exponential model best describes infectivity of CBV. The analysis of 172 samples of treated drinking water supplies described in this study revealed the presence of CBVs in 11% (water treatment unit A) and 16% (water treatment unit B) of the samples. This incidence of CBV was used as a basis for risk assessment. The results indicated that the drinking water supplies concerned constitute a risk of CBV infection of 3.91 × 10-3 (unit A) and 7.4 × 10-3 (unit B) per year. The estimated risk of infection are about an order of magnitude higher than the yearly acceptable risk of one infection per 10,000 consumers proposed for drinking water supplies.

New methods for the detection of viruses: call for review of drinking water quality guidelines

2001 ◽  
Vol 43 (12) ◽  
pp. 1-8 ◽  
Author(s):  
W.O.K. Grabow ◽  
M.B. Taylor ◽  
J.C. de Villiers
Keyword(s):  
Water Quality ◽  
Cell Culture ◽  
Drinking Water ◽  
Water Samples ◽  
Raw Water ◽  
Water Supplies ◽  
Water Quality Guidelines ◽  
Quality Guidelines ◽  
Treated Drinking Water ◽  
Drinking Water Samples

Drinking water supplies which meet international recommendations for source, treatment and disinfection were analysed. Viruses recovered from 100 L-1,000 L volumes by in-line glass wool filters were inoculated in parallel into four cell culture systems. Cell culture inoculation was used to isolate cytopathogenic viruses, amplify the nucleic acid of non-cytopathogenic viruses and confirm viability of viruses. Over a period of two years, viruses were detected in 23% of 413 drinking water samples and 73% of 224 raw water samples. Cytopathogenic viruses were detected in 6% raw water samples but not in any treated drinking water supplies. Enteroviruses were detected in 17% drinking water samples, adenoviruses in 4% and hepatitis A virus in 3%. In addition to these viruses, astro- and rotaviruses were detected in raw water. All drinking water supplies had heterotrophic plate counts of <100/mL, total and faecal coliform counts of 0/100 mL and negative results in qualitative presence-absence tests for somatic and F-RNA coliphages (500 mL samples). These results call for a revision of water quality guidelines based on indicator organisms and vague reference to the absence of viruses.

Enteric viruses in drinking water supplies

2002 ◽  
Vol 2 (3) ◽  
pp. 17-22
Author(s):  
A.P. Wyn-Jones ◽  
J. Watkins ◽  
C. Francis ◽  
M. Laverick ◽  
J. Sellwood
Keyword(s):  
Drinking Water ◽  
Heavy Rainfall ◽  
Liquid Culture ◽  
Plaque Assay ◽  
Enteric Viruses ◽  
Enteric Virus ◽  
The Other ◽  
Raw Water ◽  
Rt Pcr ◽  
Water Supplies

Two rural spring drinking water supplies were studied for their enteric virus levels. In one, serving about 30 dwellings, the water was chlorinated before distribution; in the other, which served a dairy and six dwellings the water was not treated. Samples of treated (40 l) and untreated (20 l) water were taken under normal and heavy rainfall conditions over a six weeks period and concentrated by adsorption/elution and organic flocculation. Infectious enterovirus in concentrates was detected in liquid culture and enumerated by plaque assay, both in BGM cells, and concentrates were also analysed by RT-PCR. Viruses were found in both raw water supplies. Rural supplies need to be analysed for viruses as well as bacterial and protozoan pathogens if the full microbial hazard is to be determined.

The assessment of biofilm community composition on plumbing materials in filtered and unfiltered water distribution systems

2003 ◽  
Vol 3 (1-2) ◽  
pp. 187-191
Author(s):  
M.M. Critchley ◽  
N.J. Cromar ◽  
H.J. Fallowfield
Keyword(s):  
Drinking Water ◽  
Fatty Acid ◽  
Community Composition ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Polymer Materials ◽  
Fatty Acid Profiles ◽  
Water Supplies ◽  
Drinking Water Distribution Systems

Biofilms have been extensively characterised within drinking water distribution systems. However, the significance of materials on biofilm species diversity is not established. This study investigated the community composition of biofilms on plumbing materials receiving filtered and unfiltered water supplies. Biofilms were extracted from polybutylene, polyethylene, cross-linked polyethylene, unplasticised polyvinyl chloride and copper tubes in sampling rigs receiving Murray-Onkaparinga water before or after filtration. Biofilms were extracted and analysed for fatty acid composition using the FAME™ methodology. There were differences in the fatty acid profiles of biofilms and the respective water supplies, indicating differences in the attached and planktonic communities. The results also showed significant differences in the fatty acid profiles of biofilms on the polymer materials compared to copper, suggesting variations in biofilm populations on the different materials. The potential for materials to select for microbial populations has significant implications for the ecology of drinking water biofilms.

Sign in / Sign up

Export Citation Format

Share Document