Enterobacteriaceae Positive but less than 10

Hello,

We are consistently getting Enterobacteriaceae Positive but <10 in whey protein powder. The method the lab is using is the same, its just an enumeration step or not. How is this possible? Does it have something to do with viable bacteria or not? I just find it so hard to believe that we are consitently seeing 1-9cfu/g in samples, seems very unlikely to me. Rarely see anything >10 cfu/g, if at all!

ThoughtS? 

<10 cfu/g is a minimum detectable limit, no? 

<10 cfu/g is a minimum detectable limit, no? 

Yes the test has a limit of 10cfu/g. But the same sample is positive for EB. This means the sample must be between 1-9cfu/g. 

To me <10 cfu/g is negative.

To me <10 cfu/g is negative.

Yes, but the sample is testing positive on a pos/neg. So although it is <10 it is positive. 

Yes, but the sample is testing positive on a pos/neg. So although it is <10 it is positive. 

What type of analysis are you using for your qualitative result? Assuming you're plating for quant. 

Hello,

 

We are consistently getting Enterobacteriaceae Positive but <10 in whey protein powder. The method the lab is using is the same, its just an enumeration step or not. How is this possible? Does it have something to do with viable bacteria or not? I just find it so hard to believe that we are consitently seeing 1-9cfu/g in samples, seems very unlikely to me. Rarely see anything >10 cfu/g, if at all!

ThoughtS? 

Hi Letterman,

Procedures are unknown but semantically -

Enterobacteriaceae is repeatedly not detected in a sample size of 0.1gram by application of Procedure X1 (?)

Enterobacteriaceae is (repeatedly?) detected in a sample size of A(?) gram by application of Procedure X2 (?)

Perhaps you can clarify the unknowns (repeatedly, X1,X2,A) to avoid a case of "Peaches and Strawberries".