Ancient genomics sheds light on past plagues

This caught my eye as I had just talked a bit about Yersinia pestis in class about 1-2 weeks ago. This species is generally assigned as the causative agent of the plague that wiped out 1/3 of Europe in the mid1300's. Researchers obtained DNA from Black Plague victims from the 1300's and were able to pull out and sequence the genome of the bacterium that caused it. Their initial questions were 1) was Y. pestis actually the cause and 2) if so, how did this strain relate to today's strains?

When they compared the genome to modern Y. pestis, they found that 1) it was indeed Y. pestis, and 2) there is little change between the ancient strain and the current strain suggesting that it wasn't necessarily a abnormally virulent strain.

http://www.nature.com/nature/journal/vaop/ncurrent/full/nature10549.html

A few posts ago I noted the use of genomics to track modern epidemics. This study adds a unique component by analyzing ancient genomes. Took a peek at the methods - they had to enrich the DNA by using modern Y. pestis fragments to pull out the ancient bacterial DNA, otherwise it's a needle in a haystack!