Table 4: O serotype-based grouping and the number of the colonies randomly selected from the agar plates inoculated with the starting mix (without IMS) and the solution or the suspension remaining in each of the four wells after PickPen-IMS treatment (with IMS).

O serotype-based grouping Number of the colonies selected 1:
Without IMS (Starting mix)
With IMS2
Group O serotype No wash (First well) First wash (Second well) Second wash (Third well) Yield (Fourth well)
Non-target O143 - ++++ - - -
O166 - - - - -
OUT + +++ + + -
O126 ++ +++ + - -
O6 ++ ++ + - -
O124 ++ ++ - - -
Subtotal 24 (33.3 %) 61 (84.7 %) 4 (26.7 %) 4 (19.0 %) 0 (0 %)
Target O157 + + - - +++
O91 ++ - - + ++++
O26 +++ + - + +++
O145 - - + - +
O103 +++ + + - +++
O111 ++ ++ ++ +++ ++
Subtotal 48 (66.7 %) 11 (15.3 %) 11 (73.3 %) 17 (81.0 %) 72 (100 %)
Total 72 72 15 21 72


1Designations for the number of the colonies: ? , 0; +, 1 5; ++, 6 10; +++, 11 15; ++++, 16 23.
2Designation of the sample solution or suspension is explained in Materials and Methods