The bacteria-killing recommendation by @HaLaBi is excellent.
What I do to take care of smells when I travel is carry some dryer sheets. I'll fold the item (clothes) over the dryer sheet or in the case of my suitcase, put a couple of dryer sheets in it and zip it up. The more dryer sheets you use, the more it'll smell like, well, dryer sheets. But I prefer that smell over the sweaty stench.
I also carry a couple of packets of wet wipes and clean off my daypack if necessary.
