Robert Koch isolated and
characterized the bacilli of anthrax, and tuberculosis and demonstrated their
causative role by a series of experiments.
After identifying the tubercle bacillus, Koch has advocated his
postulate, in order to distinguish a pathogenic microbe from adventitious
microbes. The impact of his work towards the end of 19th century lead to
the discovery of “specific toxins” made by the causative bacteria for
diphtheria and tetanus and “antibodies” produced in host animals against the specific toxins. His findings led to immunization therapy. He was also awarded the Nobel prize.