Untitled

Tewari, Suman

doi:10.1023/a:1023642113645

Cited by 7 publications

(1 citation statement)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Results indicated a screening test that is more specific than it is sensitive which performs better at fecal coliform concentrations much higher than those recommended for drinking water. As suggested previously, the false negatives (47/358) could reflect the lack of adequate sensitivity at concentrations of fecal coliforms less than 10 CFU per 100 ml, or could be due to the presence of TTC that are not associated with sulfate-reducing bacteria (Tewari et al 2003; Vasudevan and Tandon 2008; Wright et al 2012). Likewise, false positive results (15/358) could have been due to environmental hydrogen sulfide producing bacteria that are not associated with TTC, which can be also present in tropical groundwater (Kaspar et al 1992; Pant et al 2002; Janda and Abbott 2006; Wright et al 2012).…”

Section: Resultsmentioning

confidence: 93%

Feasibility of the hydrogen sulfide test for the assessment of drinking water quality in post-earthquake Haiti

Weppelmann

Alam

Widmer

et al. 2014

Environ Monit Assess

View full text Add to dashboard Cite

In 2010 a magnitude 7.0 earthquake struck Haiti, severely damaging the drinking and waste water infrastructure and leaving millions homeless. Compounding this problem, the introduction of Vibrio cholera resulted in a massive cholera outbreak that infected over 700,000 people and threatened the safety of Haiti’s drinking water. To mitigate this public health crisis, non-government organizations installed thousands of wells to provide communities with safe drinking water. However, despite increased access, Haiti currently lacks the monitoring capacity to assure the microbial safety of any of its water resources. For these reasons, this study was designed to assess the feasibility of using a simple, low cost method to detect indicators of fecal contamination of drinking water that could be implemented at the community level. Water samples from 358 sources of drinking water in the Léogâne flood basin were screened with a commercially available hydrogen sulfide test and a standard membrane method for the enumeration of thermotolerant coliforms. When compared with the gold standard method, the hydrogen sulfide test had a sensitivity of 65% and a specificity of 93%. While the sensitivity of the assay increased at higher fecal coliform concentrations, it never exceeded 88%, even with fecal coliform concentrations greater than 100 colony forming units per 100 milliliters. While its simplicity makes the hydrogen sulfide test attractive for assessing water quality in low resource settings, the low sensitivity raises concerns about its use as the sole indicator of the presence or absence of fecal coliforms in individual or community water sources.

show abstract

Section: Resultsmentioning

confidence: 93%

Feasibility of the hydrogen sulfide test for the assessment of drinking water quality in post-earthquake Haiti

Weppelmann

Alam

Widmer

et al. 2014

Environ Monit Assess

View full text Add to dashboard Cite

show abstract

Validation of the H2S method to detect bacteria of fecal origin by cultured and molecular methods

McMahan

Devine

Grunden

et al. 2011

Appl Microbiol Biotechnol

View full text Add to dashboard Cite

Using biochemical and molecular methods, this research determined whether or not the H(2)S test did correctly identify sewage-contaminated waters by being the first to use culturing and molecular methods to identify the types and numbers of fecal indicator organisms, pathogens, and other microbes present in sewage samples with positive H(2)S test results. For the culture-based method, samples were analyzed for the presence of fecal bacteria by spread plating the sewage sample onto differential and selective media for Aeromonas spp., Escherichia coli, sulfite-reducing clostridia, H(2)S-producing bacteria, and Salmonella/Shigella spp. The isolates were then: (1) tested to determine whether they were H(2)S-producing organisms and (2) identified to the genus and species level using biochemical methods. The molecular method used to characterize the microbial populations of select samples was terminal restriction fragment length polymorphisms. These experiments on sewage provided evidence that positive H(2)S tests consistently contained fecal bacteria and pathogens. There were strong relationships of agreement between the organisms identified by both methods tested. This study is an important advance in microbial water quality detection since it is focused on the evaluation of a novel, low-cost, water microbiology test that has the potential to provide millions of people worldwide access to water quality detection technology. Of prime consideration in evaluating water quality tests is the determination of the test's accuracy and specificity, and this article is a fundamental step in providing that information.

show abstract

Serogroups of Escherichia coli from Drinking Water

Ramteke

Tewari

2006

Environ Monit Assess

Self Cite

View full text Add to dashboard Cite

Fifty seven isolates of thermotolerant E. coli were recovered from 188 drinking water sources, 45 (78.9%) were typable of which 15 (26.3%) were pathogenic serotypes. Pathogenic serogroup obtained were 04 (Uropathogenic E. coli, UPEC), 025 (Enterotoxigenic E. coli, ETEC), 086 (Enteropathogenic E. coli, EPEC), 0103 (Shiga-toxin producing E. coli, STEC), 0157 (Shiga-toxin producing E. coli, STEC), 08 (Enterotoxigenic E. coli, ETEC) and 0113 (Shiga-toxin producing E. coli, STEC). All the pathogenic serotypes showed resistance to bacitracin and multiple heavy metal ions. Resistance to streptomycin and cotrimazole was detected in two strains whereas resistance to cephaloridine, polymixin-B and ampicillin was detected in one strain each. Transfer of resistances to drugs and metallic ions was observed in 9 out of 12 strains studied. Resistances to bacitracin were transferred in all nine strains. Among heavy metals resistance to As(3+) followed by Cr(6+) were transferred more frequently.

show abstract

Untitled

Cited by 7 publications

References 13 publications

Feasibility of the hydrogen sulfide test for the assessment of drinking water quality in post-earthquake Haiti

Feasibility of the hydrogen sulfide test for the assessment of drinking water quality in post-earthquake Haiti

Validation of the H2S method to detect bacteria of fecal origin by cultured and molecular methods

Serogroups of Escherichia coli from Drinking Water

Contact Info

Product

Resources

About