Sunday, June 22, 2014

This Week's Sci-Light!

A key component of being sci-curious is contemplating the unknown. To be sci-curious, you can revisit answered questions where details were forgotten, delve into unanswered questions or ask novel questions. Developing techniques and systems to answer these questions is, in essence, the mission of a scientist. Among the sci-curious pioneers is a team led by a Penn State University research associate, Bodo Linz. Bodo Linz and her colleagues characterized the interaction between the human immune system and invading bacteria to uncover how the bacteria were able to elude the immune system in the article Burst of Mutations During Initial Infection Allows Bacteria To Evade Human Immune Response.

Electron Microscopic image of H. pylori. H. pylori was recently 
discovered to have a high rate of mutation during the initial phase of infection. 
Credit: Yutaka Tsutsumi, Fujita Health University School of Medicine

During the chronic phase of infection, the mutation rate of Helicobacter pylori, a common stomach bacteria, had previously been established. Though this data has proved useful for understanding infection, no one had yet to investigate the rate of mutation during the initial acute phase of infection due to experimental difficulty. The research team took two different approaches to characterize H. pylori's mutation rate during infection. One method involved isolated bacteria from volunteers and sequencing its genome - this genome served as a baseline. After removing all H. pylori from the volunteers via antibiotics, they were re-infected with the same H. pylori that was removed from them. After 20 days and 44 days of infection, the bacteria was isolated and its genome was sequenced again. The bacteria was then removed from the volunteers using another antibiotic treatment. From this, the genomes could be compared. It was found that the rate of mutation during the acute phase of infection was 30 to 50 times greater than during the chronic phase of infection. Researchers surmised that H. pylori used the higher rate of mutation to promote speedy evolution and avoid the immune system all together. 

If this article has got you sci-curious, find out the other method the researchers used to characterize the rate of mutations during the acute phase of infection by clicking the link! 

Written by Jacob Steenwyk