Fecal coliform elevated-temperature test: a physiological basis

Dockins, William S.; McFeters, Gordon A.

doi:10.1128/aem.36.2.341-348.1978

“…Using sterile technique, bacteria from blue colonies were transferred using the streak-for-isolation technique to pairs of nutrient agar dishes. One dish from each pair was incubated overnight at 37 • C and the other was incubated at 45 • C as a test for thermotolerance [28,29]. After incubation and growth of colonies, Gram staining was performed to determine if the colonies contained Gram-negative coliform bacteria (indicating E. coli).…”

Section: Methodsmentioning

confidence: 99%

Unexpected Prevalence of eae-Positive Escherichia coli in the Animas River, Durango, Colorado

Hamner

¹

,

Fenster

²

,

Nance

³

et al. 2019

IJERPH

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Since 2014, biology students at Fort Lewis College have studied the water quality of the Animas River in Durango, Colorado. Environmental microbiology and molecular biology techniques have been employed to study Escherichia coli isolates from the river and to define characteristics of the bacteria related to public health. E. coli was found in the river, as well as in culverts and tributary creeks that drain into the river within the Durango city limits. Concentrations of E. coli in the river occasionally exceeded the US EPA guideline of 126 CFU per 100 mL for recreational water use. Many of the E. coli isolates were able to be grown at 45 °C, an indication of mammalian origin. Unexpectedly, 8% of the isolates contained the intimin (eae) gene, a virulence gene characteristic of two pathotypes of E. coli, the enterohemorrhagic and enteropathogenic E. coli. Several isolates tested were resistant to multiple antibiotics commonly used in animal and human medicine. Further study is warranted to determine the source of these bacteria entering the Animas River, and to further characterize the possible disease potential of multi-antibiotic resistant and virulence gene-containing isolates found in a semi-rural/urban setting.

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“…(Carrero-Colon et al, 2011). However, the fecal coliform assay is based on the assumption that E. coli is the only species from the group that can grow at higher temperatures (Dockins and McFeters, 1978).…”

Section: E Coli and Coliformsmentioning

confidence: 99%

“…and Klebsiella spp. with fecal sources is uncommon, they are part of the fecal coliform group, making the correlation between fecal coliforms and fecal contamination not always reliable (Dockins and McFeters, 1978;Johannessen et al, 2002). Moreover, prior to the realization of this limitation, fecal coliforms were commonly used as indicators of fecal contamination in food (Diez-Gonzalez, 2011).…”

Section: E Coli and Coliformsmentioning

confidence: 99%

A study of the microbial contamination in imported and domestic fresh produce at retail level in Ontario

Chung¹

2023

Preprint

0

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Globalization has enabled the year-round availability of imported fresh produce in Toronto, supplementing the variety of locally grown produce in Ontario. Increased consumption of produce has led to more foodborne outbreaks, with E. coli O157:H7 as the second most frequent cause of illnesses. In this study, the levels of heterotrophic bacteria, coliforms, and generic E. coli were compared between three types of imported and local produce. Significantly higher levels (p<0.04) of heterotrophic bacteria were found in imported basil. Local romaine (p<0.01) and local spinach (p<0.001) contained significantly higher levels of coliforms. Local spinach also had a significantly higher (p<0.005) number of samples with coliform levels above 100 CFU/g. Although no statistical significance was found between the presence of E. coli and origin of produce, the five imported samples positive for E. coli compared to zero local samples supports the hypothesis that imported produce is more susceptible to microbial contamination.

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“…(Carrero-Colon et al, 2011). However, the fecal coliform assay is based on the assumption that E. coli is the only species from the group that can grow at higher temperatures (Dockins and McFeters, 1978).…”

Section: E Coli and Coliformsmentioning

confidence: 99%

A study of the microbial contamination in imported and domestic fresh produce at retail level in Ontario

Chung¹

2023

Preprint

0

View full text Add to dashboard Cite

Globalization has enabled the year-round availability of imported fresh produce in Toronto, supplementing the variety of locally grown produce in Ontario. Increased consumption of produce has led to more foodborne outbreaks, with E. coli O157:H7 as the second most frequent cause of illnesses. In this study, the levels of heterotrophic bacteria, coliforms, and generic E. coli were compared between three types of imported and local produce. Significantly higher levels (p<0.04) of heterotrophic bacteria were found in imported basil. Local romaine (p<0.01) and local spinach (p<0.001) contained significantly higher levels of coliforms. Local spinach also had a significantly higher (p<0.005) number of samples with coliform levels above 100 CFU/g. Although no statistical significance was found between the presence of E. coli and origin of produce, the five imported samples positive for E. coli compared to zero local samples supports the hypothesis that imported produce is more susceptible to microbial contamination.

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Fecal coliform elevated-temperature test: a physiological basis

Cited by 14 publications

References 20 publications

Unexpected Prevalence of eae-Positive Escherichia coli in the Animas River, Durango, Colorado

Unexpected Prevalence of eae-Positive Escherichia coli in the Animas River, Durango, Colorado

A study of the microbial contamination in imported and domestic fresh produce at retail level in Ontario

A study of the microbial contamination in imported and domestic fresh produce at retail level in Ontario

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