About 2/3 of the population has Helicobacter pylori infecting their stomach lining and small intestines. For the most part patient are asymptomatic; however the symptoms range from stomach ulcers (mild) to stomach cancer (severe).Most Microbiologists know the famous example of H. pylori and stomach ulcers fulfilling Koch’s postulate. When Barry Marshall swallowed H. pylori culture to prove he would develop stomach ulcers (causation). Now that’s dedication to your craft!
Most people aren’t aware of the history and discovery of H. pylori. Interestingly it was first observed in the 20th century. The spiral organism was seen in a biopsy from the human stomach (carcinoma occasionally adjacent). The next substantial encounter with H. pylori was by scientists Doenges, Freedberg, and Baron in 1940. Of the gastric specimens approximately 40% were positive for spirochetes. Unfortunately the bacteria were unable to be cultured for future study. During the 50’s a man named Palmer challenged the discovery. Out of 1,000 gastric biopsies, no spirochetes were found. Statistically this is impossible around that time %50 of the population was infected.
Between 1979 and 1984, Warren and Marsh were the first to successfully isolate and culture H. pylori. By 1979 Warren, on multiple occasions, observed patients with the spirochete and some associated inflammation. 1981 they were able to gram stain the gram-negative bacteria but could yet culture it. Treating one patient with tetracycline resulted in H. pylori diminishing. In 1982 trails were conducted to isolate H. pylori. For each patient two gastric biopsies were obtained. First biopsy is subjected to a various techniques, including microaerobic incubation. The second biopsy was treated with hematoxylinin and eosin and Warthin-Starry silver stains. Finally the 35 patient’s biopsy was positive for bacterial growth. How, What changed? The sample was left over Easter weekend resulting in a longer incubation period (approx. 4-5 day). The gastrointestinal and throat specimens were being thrown out after 48 hours, that’s why up until this point, H. pylori was unable to be isolated.
Jumping ahead to 2016, Otzi the Iceman the 5,300 year-old mummy contain DNA of Helicobacter pylori. Otzi was discovered on 1991, between Austria and Italy, in a block of ice. For the past 20 years continual test/scans have been preformed to discover what his life was like. Inquisitive scientists took a sample of Otzi stomach, searching for DNA. Interestingly, the H. pylori strain was closely related to the Asian strain rather than the European. The European strain is made up of the Asian and African strain. Confirming the African strain transmit to Europe until after The Ice man’s time. It was also revealed that Otzi’s H.pylori strain was virulent with signs of inflammation.
For now H. pylori has infected humans for at least 5300 years. However we are now aware of H. pylori, ailments it causes, treatments, and the evolution in the human gut.