What Causes Klebsiella Pnemonia?

i had a LAVH almost 6 weeks ago.... with bleeding ever since. at just over 5 weeks doctor took 6 undissoved stitches out of my vaginal cuff.. and used silver nitrate to stop bleeding. which only worked for that day. today i received a call saying i need to go on anitbiotics as when she was doing the procedure she took a culture. i have klebsiella pnemonia. i do not understand how i have this.... can you help?