The Centers for Disease Control, the World Health Organization and epidemiologists throughout the world are calling for more prudent use of antibiotics. Ever since doctors started using penicillin to kill bacterial infections in the 1940's, researchers have worried some bacteria would become resistant to antibiotics. Their fears are now coming true as scientists discover antibiotic resistant germs They say so-called "superbugs" will leave doctors defenseless against some illnesses. Minnesota Public Radio's Tom Scheck has the first of three reports...