You are to be commended for your concern in guarding your cat's urinary tract health. The information you were given is partially right, in that bacterial infections may accompany other lower urinary tract problems (FLUTD), such as urine crystals or uroliths (bladder stones).
A great deal of research has been on-going as to the relationship of diet to urinary tract health, and the thinking has changed over a period of just a few years. Originally it was thought that diets high in magnesium and ash contributed to the problem; now more emphasis is being placed on the pH of urine (acidic or alkaline). (Veterinarians recommend a range between 6.0 and 6.5)
Unfortunately, special diets which prevent the formation of one kind of crystal can actually cause the other, so I don't recommend a special diet for a one year old cat with no symptoms, unless your veterinarian prescribes one.
Generally, a good quality commercial food should be fine for your cat. I would recommend avoiding fish flavored foods, which are said to be suspect in crystal formation. I would also recommend that you supplement your cat's dry food diet with a small amount of canned food each day, also avoiding the fish flavors, with the eventual goal of getting him on a mostly- or wholly-canned food diet. Make sure your cat always has plenty of fresh, clean water, and avoid feeding him table scraps. Watch carefully for any signs of distress, such as straining to urinate or missing the litterbox.
For more information on both FLUTD and diet, see the Related Resources at the right.