Great pioneers in the wolrd of antibiotics were Robert Koch, Gerhard Domagk, Alexander Flemming or Selman Waksman.

There is a web site you can check out or go to google.com and do a search for the names.
http://www-micro.msb.le.ac.uk/Tutorials/dfwt/dfwt1.html

It is hard to say who came up with the first antibiotics.More than 3000 years ago the Egyptians, Chinese and Indians from Central America were using natural compounds as antibiotics, although at the time they probably just thought of it as magic. In the 1890's two German doctors (Rudolf Emmerich and Oscar Low)discovered a compound they called pyocyanase and it became the first antibiotic to be used in hospitals. Unfortunately, it worked differently on different people and so it was not always very useful. In 1928 Alexander Fleming discovered penicillin. This often considered to be the first real antibiotic and is still used today. A few years later (1932) Gerhard Domagk created an antibiotic called Prontosil, it was the first Sulfa drug. Interestingly its original use was as a clothing dye, it makes clothes bright orange.
I hope some of these names help you.