Recent health reports have shown that reusable grocery shopping bags can be a breeding ground for illness-causing bacteria like E. coli and salmonella. It's easy to understand why: Drippings from meat or seafood can leak onto the bags and cause mold, mildew and bacteria to grow. The healthy solution is to invest in machine washable bags -- like those made of nylon -- that can be washed and disinfected. Also, designate different bags for meat and produce. This will reduce cross contamination.