Search results
Results From The WOW.Com Content Network
The fecal coliform assay is intended to be an indicator of fecal contamination; more specifically of E. coli which is an indicator microorganism for other pathogens that may be present in feces. Presence of fecal coliforms in water may not be directly harmful, and do not necessarily indicate the presence of feces. [1]
Coliform bacteria are defined as either motile or non-motile Gram-negative non-spore forming bacilli that possess β-galactosidase to produce acids and gases under their optimal growth temperature of 35–37 °C. [1]
Consequently, the National Technical Advisory Committee in the US recommended the following standard for recreational waters in 1968: 10 percent of total samples during any 30-day period should not exceed 400 fecal coliforms/100 mL or a log mean of 200/100 mL (based on a minimum of 5 samples taken over not more than a 30-day period).
The presence of some coliforms indicate fecal contamination. The term "IMViC" is an acronym for each of these tests. "I" is for indole test; "M" is for methyl red test; "V" is for Voges-Proskauer test, and "C" is for citrate test. The lower case "i" is merely for "in" as the Citrate test requires coliform samples to be placed "in Citrate".
For premium support please call: 800-290-4726 more ways to reach us
Skip to main content. Subscriptions; Animals
By testing for coliforms, especially the well known Escherichia coli (E. coli), which is a thermotolerant coliform, one can determine if the water has possibly been exposed to fecal contamination; that is, whether it has come in contact with human or animal feces. It is important to know this because many disease-causing organisms are ...
In a sample, E. coli, which is citrate-negative, can be distinguished from non-fecal, citrate-positive coliforms that are often found in water, soil, and on plants using Simmons’ agar. Additionally, Simmons’ agar is commonly used as part of the IMViC tests to identify coliforms. [4]