Comparison of commercially available Escherichia coli enumeration tests: Implications for attaining water quality standards

Hamilton, William P.; Kim, Moonil; Thackston, Edward L.

doi:10.1016/j.watres.2005.02.006

Cited by 57 publications

(40 citation statements)

References 23 publications

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“…E. coli acts as an indicator organism for the microbiological quality of food and beverages. 13 Moreover, E. coli is not a normal member of the oral flora, and lingual infections with E. coli are rarely seen, despite daily exposure of E. coli strains from animal reservoirs, environmental vehicles, food processing environments, and nutriments through the mouth. 14 -16 The reason for the natural resistance of tongue against E. coli infection is not understood.…”

Section: Discussionmentioning

confidence: 99%

Psoriasin (S100A7) is a principal antimicrobial peptide of the human tongue

et al. 2008

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The human tongue is particularly resistant to bacterial infections although the mouth is continuously exposed to a complex and abundant ensemble of microbes, such as the common intestinal bacterium Escherichia coli. We show that lingual epithelia produce and release, as a primary E. coli-killing compound, the S100 protein psoriasin. No significant reduction in psoriasin release could be achieved through repeated rinsing of the epithelial surface of the tongue. Psoriasin is produced in the upper layers of the lingual epithelia but is lacking in the most superficial and basal cells. It displays a gradient pattern of expression with decreasing expression from the anterior one-third to the posterior portion of the tongue. Thus, psoriasin may be the key to the resistance of the human tongue toward E. coli.

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Section: Discussionmentioning

confidence: 99%

Psoriasin (S100A7) is a principal antimicrobial peptide of the human tongue

et al. 2008

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“…faecal/thermotolerant coliforms (Leclerc et al 2001;Alonso et al 1999) is regarded as an indicator of the microbiological standard of that water (Hamilton et al 2005). Due to consistent reports of illnesses associated with presence of Escherichia coli in water coupled with the fact that some strains are pathogens of faecal origin, E. coli is considered to be an effective indicator of recent faecal contamination of water (Hurst et al 2002).…”

Section: Introductionmentioning

confidence: 99%

Inactivation and sub-lethal injury of Escherichia coli in a copper water storage vessel: effect of inorganic and organic constituents

Sharan

Chhibber

Attri

et al. 2010

Antonie van Leeuwenhoek

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This study provides information on the effects of inorganic and organic constituents on inactivation and sub-lethal injury of Escherichia coli in water stored in a copper vessel. E. coli suspensions were stored for up to 24 h in copper vessels containing one of the following dissolved constituents at 1 g/l: salts of inorganic ions, carbohydrates, proteins and complex natural organic mixtures. Samples were surface plated onto (i) nutrient agar, incubated under standard aerobic conditions to provide conventional counts for uninjured bacteria count and onto (ii) nutrient agar plates with 0.5 g/l sodium pyruvate incubated under anaerobic conditions to enumerate sub-lethally injured (oxygen-sensitive) bacteria alongside their healthy counterparts. The concentration of dissolved copper in the stored water was determined using atomic absorption spectrophotometry. The addition of chloride salts resulted in a faster inactivation of E. coli compared to pure water with no dissolved additives, irrespective of the counterion. In contrast, a slower inactivation was observed in the presence of Na(2)SO(4), NaNO(3) and NaNO(2) when compared to NaCl. Addition of the carbohydrates glucose, lactose and starch gave broadly similar results to those obtained using unsupplemented water. However, the addition of amino acids, proteins, humic acid or complex organic mixtures caused a dramatic decrease in inactivation of E. coli, with evidence of a greater number of sub-lethally injured bacteria than was seen with other added constituents. The amount of copper was highest in stored water containing amino acids and complex organic constituents, with the slow inactivation most likely to be due to complex formation between leached copper and these organic constituents. The present study clearly demonstrates that water composition, particularly natural organic constituents, has a substantial impact on the antibacterial effectiveness and dissolved copper concentration of water stored in copper vessels and that both aspects will need to be considered in terms of their impact on the practical use of copper-based systems for small-scale water treatment.

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“…3 as diamond markers and dashed curve. The total coliform data of Cooby, Perseverance and Cressbrook dams were provided by the laboratory services of Mt Kynoch water treatment plant in Toowoomba,Australia, while the total coliform of the rest water bodies was measured in the lab applying membrane filtration standard method (method 9222 B in [29]) using m-ColiBlue24 Broth [30,31].…”

Section: Doc Fractions Of Water Bodiesmentioning

confidence: 99%

Exploring the correlations between common UV measurements and chemical fractionation for natural waters

Al-Juboori

Yusaf

Pittaway

2016

Desalination and Water Treatment

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A B S T R A C TChemical fractionation is a powerful tool for unravelling the reasons behind water treatment problems such as the formation of disinfection by-products (DBPs). This technique can however be costly and time-consuming. Hence, exploring quick affordable surrogate measurements to this technique is of great importance for water treatment operators. In this study, the correlations between aquatic carbon fractions and single wavelength and UV ratios of A 254 , A 280 , A 254 /A 204 , A 250 /A 365 and A 254 /A 436 were examined for seven water bodies located in South-east Queensland, Australia. It was observed that A 254 /A 204 has a strong and significant correlation with hydrophobic/hydrophilic ratio (R 2 = 0.984). A 250 /A 365 exhibited a weak but significant correlation with the same fraction ratio (R 2 = 0.687) suggesting that the chemical fractions cannot be assumed of a certain molecular size. A 254 /A 436 had a weak and insignificant correlation with carbon fractions (R 2 = 0.0506). The hydrophobic fraction of the seven water bodies showed a strong and significant correlation with A 254 (R 2 = 0.968) and A 280 (R = 0.958). The diverse carbon source of the tested water bodies confirms the reliability of the observed correlations. The results of this study highlight the potential use of UV absorbance as a real-time technique for monitoring the structural change of aquatic carbon.

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Comparison of commercially available Escherichia coli enumeration tests: Implications for attaining water quality standards

Cited by 57 publications

References 23 publications

Psoriasin (S100A7) is a principal antimicrobial peptide of the human tongue

Psoriasin (S100A7) is a principal antimicrobial peptide of the human tongue

Inactivation and sub-lethal injury of Escherichia coli in a copper water storage vessel: effect of inorganic and organic constituents

Exploring the correlations between common UV measurements and chemical fractionation for natural waters

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