Proper use of the comma in 'and'

You don't have a comma after 'and' anywhere here, but you should remove the one after 'low-acid foods'. Notice I added an 's' to food. The comma after poultry in the list is prefered. This is called the Harvard or Oxford comma.

Pressure canning is a method used for processing vegetables and other low-acid food, such as meat, poultry, and fish.

There are occasions in which a comma following the conjunction 'and' would be apppropriate. If there is an introductory clause that starts the second sentence that would normally take a comma, it should be used.