Evaluation of a commercial β‐glucuronidase test for the rapid and economical identification of<i>Escherichia coli</i>

Pérez, J L; Berrocal, C.I.; Berrocal, Liliana

doi:10.1111/j.1365-2672.1986.tb01727.x

Cited by 49 publications

(21 citation statements)

References 11 publications

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“…This is a very uncommon characteristic for E. coli. A positive indole reaction is normally used as a basic criterion for the proper identification of E. coli in both medical and food samples (7,30,42). Thus, this basic identification characteristic has to be reconsidered, at least in dealing with the analysis of mussels.…”

Section: Discussionmentioning

confidence: 99%

Environmental Factors Influencing Human Viral Pathogens and Their Potential Indicator Organisms in the Blue Mussel, Mytilus edulis : the First Scandinavian Report

Hernroth¹,

Conden-Hansson

Rehnstam-Holm

et al. 2002

Appl Environ Microbiol

288

143

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This study was carried out in order to investigate human enteric virus contaminants in mussels from three sites on the west coast of Sweden, representing a gradient of anthropogenic influence. Mussels were sampled monthly during the period from February 2000 to July 2001 and analyzed for adeno-, entero-, Norwalk-like, and hepatitis A viruses as well as the potential viral indicator organisms somatic coliphages, F-specific RNA bacteriophages, bacteriophages infecting Bacteroides fragilis, and Escherichia coli. The influence of environmental factors such as water temperature, salinity, and land runoff on the occurrence of these microbes was also included in this study. Enteric viruses were found in 50 to 60% of the mussel samples, and there were no pronounced differences between the samples from the three sites. E. coli counts exceeded the limit for category A for shellfish sanitary safety in 40% of the samples from the sites situated in fjords. However, at the site in the outer archipelago, this limit was exceeded only once, in March 2001, when extremely high levels of atypical indole-negative strains of E. coli were registered at all three sites. The environmental factors influenced the occurrence of viruses and phages differently, and therefore, it was hard to find a coexistence between them. This study shows that, for risk assessment, separate modeling should be done for every specific area, with special emphasis on environmental factors such as temperature and land runoff. The present standard for human fecal contamination, E. coli, seems to be an acceptable indicator of only local sanitary contamination; it is not a reliable indicator of viral contaminants in mussels. To protect consumers and get verification of "clean" mussels, it seems necessary to analyze for viruses as well. The use of a molecular index of the human contamination of Swedish shellfish underscores the need for reference laboratories with high-technology facilities.

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Section: Discussionmentioning

confidence: 99%

Environmental Factors Influencing Human Viral Pathogens and Their Potential Indicator Organisms in the Blue Mussel, Mytilus edulis : the First Scandinavian Report

Hernroth¹,

Conden-Hansson

Rehnstam-Holm

et al. 2002

Appl Environ Microbiol

288

143

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“…Although a recent report by Chang et al. (1989) showed that 34% of E. coli strains of human faecal origin were glucuronidase-negative, the majority of reports have shown that 9 4 9 7 % of human and environmental E. coli strains produce 8-glucuronidase (Feng & Hartman 1982;Edberg & Trepeta 1983;Hansen & Yourassowsky 1984;Van Wart & Moberg 1984;Perez et PI. 1986).…”

Section: Introductionmentioning

confidence: 99%

A rapid fluorogenic method for the detection ofEscherichia coliby the production of β‐glucuronidase

Sarhan

Foster

1991

Journal of Applied Bacteriology

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A medium containing the fluorogenic substrate 4-methylumbelliferyl-beta-D-glucuronide was developed for the isolation and identification of Escherichia coli within 7.5 h and was based on the detection of beta-glucuronidase. Optimum conditions for the rapid development of fluorescent colonies were determined. The optimum temperature was 41.5 degrees C. Development of fluorescence was delayed when carbohydrates were incorporated into the medium. Water samples were used to evaluate the medium by surface plating and membrane filtration. The frequency of false-negative results was 6.1% and false-positives were 3.7% for freshwater samples. The false-positive organisms were identified as Klebsiella spp. and Shigella sonnei. The potential applications of the medium are discussed.

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“…Isolates were tested for indole production and ␤-glucuronidase activity using EC medium containing 4-methylumbelliferyl-␤-D-glucuronide (MUG) (Remel, Lenexa, Kans.). ␤-Glucuronidase activity has been shown to be highly specific to E. coli (3,20). Other environmental bacteria with ␤-glucuronidase activity include strains of Enterobacter cloacae and Citrobacter freundii, but they are commonly negative for indole production (3,20).…”

mentioning

confidence: 99%

Clonal Populations of Thermotolerant Enterobacteriaceae in Recreational Water and Their Potential Interference with Fecal Escherichia coli Counts

McLellan

Daniels

Salmore

2001

Appl Environ Microbiol

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Bacterial strains were isolated from beach water samples using the original Environmental Protection Agency method for Escherichia coli enumeration and analyzed by pulsed-field gel electrophoresis (PFGE). Identical PFGE patterns were found for numerous isolates from 4 of the 9 days sampled, suggesting environmental replication. 16S rRNA gene sequencing, API 20E biochemical testing, and the absence of ␤-glucuronidase activity revealed that these clonal isolates were Klebsiella, Citrobacter, and Enterobacter spp. In contrast, 82% of the nonclonal isolates from water samples were confirmed to be E. coli, and 16% were identified as other fecal coliforms. These nonclonal isolates produced a diverse range of PFGE patterns similar to those of isolates obtained directly from untreated sewage and gull droppings. ␤-Glucuronidase activity was critical in distinguishing E. coli from other fecal coliforms, particularly for the clonal isolates. These findings demonstrate that E. coli is a better indicator of fecal pollution than fecal coliforms, which may replicate in the environment and falsely elevate indicator organism levels.

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Evaluation of a commercial β‐glucuronidase test for the rapid and economical identification ofEscherichia coli

Cited by 49 publications

References 11 publications

Environmental Factors Influencing Human Viral Pathogens and Their Potential Indicator Organisms in the Blue Mussel, Mytilus edulis : the First Scandinavian Report

Environmental Factors Influencing Human Viral Pathogens and Their Potential Indicator Organisms in the Blue Mussel, Mytilus edulis : the First Scandinavian Report

A rapid fluorogenic method for the detection ofEscherichia coliby the production of β‐glucuronidase

Clonal Populations of Thermotolerant Enterobacteriaceae in Recreational Water and Their Potential Interference with Fecal Escherichia coli Counts

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