WAS BLACK DEATH A STOMACH BUG MUTATION

WAS TINY MUTATION IN A TUMMY BUG THE CAUSE OF BLACK DEATH. A STUDY OF ANCIENT STRAINS OF BACTERIA IN MICE FOUND IT FAILED TO ATTACK THE LUNGS AS PURELY A GASTIC INFECTION.A SIMPLE PROTEIN-PLA-WHEN ADDED TURNED INTO PNEUMONIC PLAGUE AND ANOTHER -PLA- VARIATION CAUSED BUBONIC PLAGUE