Thanks, for the prompt replies. I'm actually worried because although the rodents are captive bred, i've read reports of some pet rodents carrying leptospirosis. I work in a hospital setting and I've seen many cases of very bad leptospira infections, some even causing death/disability. Also, leptospira can survive in rodent kidneys even after subzero temperatures.
Was chatting with my colleague today about my new pet and he mentioned about leptospirosis and me keeping frozen rodents... that's what got me worried all of the sudden.
But I think you're right, proper handling is important, since I only have one rodent supplier in my area (but i think the quality should be ok), I will probably buy a plastic container to keep the mice from now on to keep it separated from the food physically.