The age of antibiotics followed the observation by Sir Alexander Fleming that the penicillum notatum mold produced a substance capable of killing many of the common bacteria.  This observation lead to one of the great medical triumphs over disease of the 20th century.

The concept of preventing post-operative wound infections by the pre-operative or intraoperative administration of antibiotics was the brainchild of neurosurgeon Leonard Malis of New York City.  In the early 1970s Malis initiated routine use of intraoperative prophylactic antibiotics (to the consternation of his infectious disease colleagues) consisting of intramuscular gentamycin or tobramycin, intravenous vancomycin and the use of streptomycin dissolved in the irrigating fluid.  Malis vindicated his point of view in 1979 when he reported on 1,732 major operative cases with no instance of operative infection and no complication other than that related directly to antibiotic side-effect (Malis LI: Prevention of neurosurgical infection by intraoperative antibiotics, Neurosurg. 5(3):339-343, 1979).

It wasn't until the end of the 20th century that prophylactic antibiotic administration became a routine practice for surgeons.  It wasn't until 1999 that the Centers for Disease Control issued guidelines recommending the routine use of pre-operative preventive antibiotics.