Differentiating Coliform Group Bacteria
• Total Coliform Test-theoretically indicates the presence of all coliform group
bacteria, both vegetative and fecal in origin
• E. coli - a coliform species found in the intestinal tract of warm-blooded animals.
- its presence can be indicative of fresh pollution from human or animal waste
- though normally benign, some E. coli strains may be deadly (0157:H7)
• Fecal Coliform-those that ferment lactose & produce gas at 44.5 +/-0.20C within 24
+/- 2 hours
• Consist of various genera and species of coliforms that are specifically associated
with human or animal waste.
- includes E. coli as well as others
- Fecal Coliform testing can help pinpoint the source of pollution in an aquifer
or watershed and is used to monitor the disinfection of sanitary waste water before discharge.
Coliform Group Bacteria:
• Total Coliforms:
Escherichia, Enterobacter, Klebsiella, Citrobacter
• Fecal Coliforms:
Escherichia, Klebsiella, Citrobacter (60% to 90% of total coliforms are fecal coliforms) 90%+ of fecal coliforms are Escherichia (usually E. coli)