HPCs
What does the acronym HPC stand for?
Heterotrophic Plate Count
What kind of broth is used for detection of E.Coli for the membrane filtration method?
m-Coliblue
What does MPN stand for?
Most Probable Number
What broth is used to grow fecal coliforms for the membrane filtration method?
M-FC Rosalic Acid
Where do Coliforms come from?
Intestines of warm blooded animals
How many colonies are allowed in a potable water sample?
500 colonies
How many colonies is considered a countable plate?
20-60 cfu
What broth is used for the presumptive test?
LST
Lauryl Sulfate Tryptose
What is the incubation time for fecal coliforms using the Membrane Filtration method?
24 hours plus or minus 2 hours
Name all the coliform sub groups?
1. Fecal Coliform
2. E.Coli
3. Enterobacter
What kind of agar is used for the pour plate method?
Difco plate count agar
How are the units reported for E.Coli?
CFU/100mL
What broth is used for the confirmation of fecals for the MPN method?
EC Broth
At what temperature do fecal bacteria grow for the membrane filtration method?
44.5 degrees Celsius plus or minus 0.2
Which positive control can be used to grow coliforms?
1. E.Coli
2. Enterobacter
What units are HPCs reported as?
CFU/mL
Why is E.Coli considered a good indicator?
It is simple, affordable, fast, and exact.
How are MPN results reported as?
MPN/100mL
What is the holding time for fecal coliforms?
6 hours
Which negative control can be used to not grow coliforms?
Psuedomonas
What is the incubation time and temperature?
48 hours
35 degrees Celsius plus or minus 0.5 degrees Celsius
Are E.Coli pathogens?
No, they are not.
If a sample is very turbid.
How should the sample be stored before analysis?
Should be stored on ice on the way to the lab and then placed in the fridge at less than or equal to 6 degrees Celsius.
Name a least 7 items that define the coliform bacteria.
1. Facultative Anaerobic
2. Rod Shaped
3. Gram-Negative
4. Non-Spore Forming
5. Ferment Lactose
6. Gas and Acid Formation
7. Incubate for 24-28 hours at 35 degrees