The Discovery of Disease-Causing Bacteria: Part 2
Famous Scientists in Biology
Carlos Chagas (1879-1934) - discovered the blood-sucking bug Trypanosoma cruzi that causes Chagas disease. Chagas was a young Brazilian doctor who first described the disease that now bears his name. He was working Lassance in Brazil, where many railroad workers were succumbing to infectious diseases such as malaria, yellow fever, and an undiagnosed illness. They presented symptoms such as irregular heartbeats. Chagas observed household infestations of microbes dubbed “kissing bugs” - so called because they come out at night and bite people on the face to feast on their blood. He set out to prove that these microbes were causing the disease.
He examined the gut flora of these blood-sucking bugs with a simple light microscope and observed a flagellated protozoan. He also took blood samples from people and detected the parasite in the blood of a three-year old girl who had developed a fever and died after being bitten by the “kissing bugs.” And so the link between microbe and disease was made.
Lev Fishelson (Professor Emeritus at the Department of Zoology, Tel Aviv University)- discovered the Epulopiscium fishelsoni bacterium in 1985, a giant in the bacterial world. It’s one of the largest bacterium known and can be seen with the naked eye. It is about the size of a period at the end of a sentence, and if you’re a bug, that’s huge. Fishelson observed the bacterium in the guts of sturgeon fish.
Alexandre Yersin (1863-1943) - one of the discoverers of Yersinia pestis, the bacterium that causes Bubonic plague. The French-born Swiss bacteriologist was studying a plague epidemic that had broken out in China. He isolated the bacterium and observed that it lived in rats, and that fleas from the rats were transmitting the disease to people.
Harald zur Hausen (German Cancer Research Centre) - the German virologist discovered the role of papilloma viruses in cancer of the cervix, and was awarded the 2008 Nobel Prize for Physiology or Medicine for his work. He identified DNA from human papilloma viruses (HPV) in cervical tumours, and made the link that HPV caused the cancer. This went against the prevailing dogma in the 1980s that herpes simplex was the cause. His work allowed others to develop vaccines that are now routinely given.
