In general everyone must be knowing about Bubonic plague, but how many of you know about Justinian plague?..I guess very few, as this Justinian plague is currently under research. Actually, two very ancient plague-ridden teeth are now helping us to know about worst pandemics in history.
Two-old-teeth is found which was buried in Bavaria, Germany between 541 and 543 CE, around 1,500-year-old. It contains the DNA of actual plague and is said as the oldest pathogen genomes ever found.
The catch is that, in the reconstruction of Justinian genome, scientist noticed that Bubonic plague and it both are two different strains of the very same pathogen, which leads to a hint of third version rodent-carried plague, which could get introduced in future.