Wow lots of opinions about shopping bags.
I am in BC Canada and one of the big discount grocery store chains has charged for bags since they opened over 16 years ago.
A local chain started to push for reusable bags and got rid of plastic shopping bags all together (except produce bags). You can have paper shopping bags, or use reusable bags and get a discount of 3 cents per bag as well as a monthly draw for a basket of treats. They sell the reusable bags for $1.00 but they go on sale for 25 cents regularly. This store still bags your groceries, will take them to your car and does delivery for seniors and shut ins. Oh and meat is wrapped in plastic to avoid any leaks.
When we shop at Safeway and forget to bring bags from home the clerks only put a couple items in each bag. It is ridiculous.
I have never had a reusable bag rip and spill my groceries, like has happened on more than one occasion with plastic bags.
As far as bacteria goes, do the studies look at where it comes from? Does anyone measure the bacteria load in shopping carts or hand baskets? Everything I buy is packaged or wrapped before I put it in a bag. Once we get home fresh food is washed or cooked before consumption.
Oh and Fabricland, our Canadian fabric chain store charges for bags too.