supposedly bites by a human upon a human are more likely to get infected than bites by a dog. The other is that if a dog licks a wound, it is less likely to get infected. There are multiple variables to consider here, including: the immune status of the person, the degree of penetration of the wound, the location of the wound, and probably most importantly, the type of bacteria involved.

As far as dogs licking things, the latest recommendations on wound treatment is to flush the wound thoroughly daily, even with plain tap water, and then change the bandage frequently. No antibiotic dressing helps better than frequent hydrotherapy. I think it is the mechanical action of the dog's licking that helps rather than any antibacterial properties possessed by dog spit.
Was that to confusing? lol