False-colour scanning electron micrograph (SEM) of Yersinia pestis,a species of Gram negative,non- motile,capsulated,aerobic bacteria that causes bubonic plague (the Black Death of the Middle Ages) in humans. The bacteria are primarily flea- carried pathogens of rats. Transfer to man occurs when a flea is obliged to leave its dead rodent host (often because its feeding apparatus is blocked by multiplying bacteria and it is starving) and suck human blood. Infection is rapid,featuring swelling (bubo) of lymph nodes and leading to septicaemia and pulmonary infection. Magnification: x2,400 at 6x7cm size,x1,200 at 35mm size | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / CNRI |
Taille de l’image : | 3966 px × 3054 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : | - |