What antibiotic is used to treat a post op wound with klebsiella, non enteroccal strep & e coli in a diabetic?

Depends. On where the post-op wound is located and the reason for the surgery, the manner in which the cultures were collected, the sensitivities to antibiotics as determined in the laboratory, things to which the patient may be allergic, and a variety of other factors. It is unusual to see multiple different organisms without some reason. Discuss with surgeon and infectious diseases consultant.
Many possibilities. Depends if intravenous or oral use. Depends on the multiple sesitivutes the bacteria are sensitive to. Too many to list here. Could include: levaquin, (levofloxacin) cephalosporins, tygecil, zosyn, avelox, etc. Need listing of bacterial sensitivities.