I'm not understanding this. If I am reading correctly your cat has a very large lump on its nose that has been described to you as a massive infection based on exudate examination under a microscope.
The vast majority of the time, a massive infection that creates a large lump, usually indicates an abscess. If large it needs to be lanced, drained (maybe cultured) and cat on antibiotics. Very common issue in cats.
If it is not an actual abscess but inflamed, infected, individual cells then that would be cellulitis. IV antibiotics are standard treatment. Cellulitis can quickly turn into septicemia and result in death.
Again, with a massive infection the cat should be running a fever and should have an abnormal CBC.
If it is an infection did they culture it (bacterial and fungal culture) to determine what type of organism is present and do a sensitivity to determine which antibiotics or antifungal would kill it? Again, this should be a first line standard practice. Not all antibiotics kill all bacteria and if it is a fungus then no antibiotic is going to work.
If they want to do surgery to remove an actual mass, then I really cannot see how this would be an infection instead of a tumor of some sort, either benign or malignant.
The thing is, even the most inexperienced vet would know these things. So if Auburn vets are stumped it doesn't make any sense.
I too would really like to see a photo of the growth, it is very perplexing based on the descriptions.