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10. Page 8, line 26. Change “…alternative method allows uncontaminated food to be
released rapidly…” to “…alternative method can be used to allow uncontaminated food
to be rapidly released…”
11. Page 8, line 27. Change “…and protects…” to “…and prevents…”
12. Page 8, line 28. Change “…investigating outbreaks…” to “…outbreak investigations…”
Reviewer 6 (Hayes):
N/A
Reviewer 7 (Fernandez):
N/A
Reviewer 8 (Chen):
Why was the draft version of the precollaborative study result attached?
Reviewer 9 (McMahon):
N/A
e.
Supporting Data and Information
(General comments and method optimization/
precollaborative/ single laboratory validation)
:
Reviewer 1 (Achen):
The data looks clean and well produced. It looks like the data supports the estimates of
repeatability, reproducibility.
Reviewer 2 (Douey):
1. PTM study validated 6 food/env matrices with specific times of incubation. These were
reported again in the pre-collaborative study (but without new data being generated) with
differing times of incubation for the alternate method than were validated in the PTM study
(e.g., cream cheese validated in PTM study at 12 h and 24 h, pre-collaborative study
specifies a 22 to 26 h incubation for this matrix). The method was modified after the PTM
method, and 3 of the 6 matrices validated in the PTM study were re-validated after this
modification, the other 3 matrices / env. samples were not re-validated.
2. In the PTM study, 2 matrices did not provide details on the amount of sample to the
amount of diluent (.e.,g ground beef is 1:4 beef:broth; dry pet food is 1:9 etc., but there is
not details given for cream cheese or bagged lettuce on the dilution factor).
3. When HC method was used, the standard method was not always followed as written.
HC method requires all food commodities to be adjusted to a pH of between 6 to 7, this was
rarely done (e.g., in PTM study, ground beef and dry pet food with HC method did not have
pH adjustment, while the stainless steel samples were pH adjusted). This problem