View Full Version : Small Change in Plague Bacillus Altered Human History

04-07-15, 16:44
Northwestern University. "How small genetic change in Yersinia pestis changed human history: From gastrointestinal infection to bubonic plague." ScienceDaily. ScienceDaily, 30 June 2015. <www.sciencedaily.com/releases/2015/06/150630121210.htm>.

" the acquisition of a single gene caused the shift of Y. pestis from causing a primarily gastrointestinal infection to a more serious and often fatal respiratory disease. " In other words, this is how it became pneumonic plague.

"The lab also looked at variations of the gene Pla and discovered that a single modification only found in modern strains of Y. pestis was a critical adaptation for the bacteria to spread in the body and infect the lymph nodes, a form of the infection that causes bubonic plague. According to Lathem, the surprising conclusion from this aspect of the study is that, contrary to current thinking in the field, Y. pestis may have first evolved as a respiratory pathogen before it could cause the more common form of disease, bubonic plague."

This is indeed contrary to what has been thought, which was that the bubonic form was first and then it evolved to become pneumonic.

These people were doomed from the start.

"Lathem said the new research may explain how Y. pestis transitioned from causing only localized outbreaks of plague to the pandemic spread of Y. pestis such as the sixth century's Justinian Plague and the fourteenth century's Black Death."