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26.2: Introduction

  • Page ID
    40322
  • Many intestinal pathogens can be waterborne and transmitted by drinking contaminated water. It’s important to be able to test drinking water sources for contamination by pathogens, but it’s not very practical or expedient to look for the many types of pathogens that could be found (and in small numbers and often hard to grow in culture). Methods have been developed to detect organisms that are normally found in the human gut but are not normally found in soil or water. The presence of these organisms in water indicates that there may be fecal contamination of the water and therefore, intestinal pathogens might also be present. These organisms are called “indicator” organisms and the group of choice is the coliform group—Gram-negative, facultative anaerobic, non-endospore forming rods that ferment lactose to produce acid and gas in 48h at 35C. Typical coliforms that we have observed in lab are Enterobacter aerogenes and E. coli. The following tests are conducted to detect the presence of coliforms, particularly E. coli, in water samples.

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