Magnifying Human Disease
As our ability to peer into the very, very small increases, we’ve had the opportunity to see the normally invisible pathogens that have plagued humankind for centuries. Some shown here will only cause achey joints or a highly unpleasant 24 hours of food poisoning; others are much more sinister, and can cause haemorrhage, necrosis, permanent disfigurement and death.
Image, top: Scanning electron micrograph (SEM) image of Borellia burgdorferi, a spirochaete bacterium responsible for lyme disease in humans.
Second row, left: RNA is seen in yellow in the core of these polioviruses; its protein coat is seen in blue. Second row, right: Yersinia pestis, a rod-shaped Gram negative bacterium, is the causitive agent of the bubonic, pneumonic, and septicemic plagues, and was responsible for the deaths of over 1/3 of the European population at its height. It’s probably best known for causing necrosis - the violent, premature death of cells in living tissue.
Third row, left: Looking deceivingly like an oil painting, these smallpox viruses - variola major and variola minor - were some of the most infectious viruses on the planet before their eradication. The protein coat is coloured yellow, and DNA is seen in red. Third row, right: The ebola virus, seen through a coloured transmission electron micrograph. Ebola is a haemorrhagic fever, and has claimed up to a 90% fatality rate in certain epidemics.
Fourth row, left: While Escherichia coli is usually a harmless gut-dweller in humans, under certain conditions it can cause gastroenteritis, urinary tract infections, and food poisoning. Fourth row, right: A false-colour image of human papilloma viruses (HPV). Best known as the cause of genital warts, it also has a sinister side: Virtually all cervical cancers are caused by HPV infection.
Source, as well as other images, here.