The poster had asked about required micro testing in Canada
Listeria is the only pathogen where CFIA has dictated the requirements for RTE foods
(there are other requirements for other types of foods)
Most foods have a water activity above 0.95 and that will provide sufficient moisture to support the growth of bacteria, yeasts, and mold. The amount of available moisture can be reduced to a point which will inhibit the growth of the organisms. If the water activity of food is controlled to 0.85 or less in the finished product, it is not subject to the regulations of 21 CFR Parts 108, 113, and 114.
Some examples of water activity controlled low-acid canned foods, that may have an a w of greater than 0.85, are: canned cake, bread, bean paste, some chutney, salted vegetables, salted fish, guava paste, lupini beans, syrup, toppings, puddings, and some oriental specialty sauces. Water activity is usually controlled by the use of salt or sugar. There are situations where routine a w determinations need not be made during production. For example, if salt is the preservative, percent salt determinations alone may be sufficient to document control of water activity and commercial sterility.
https://www.fda.gov/...tivity-aw-foods