T-bacteriophages on E.coli.
Coloured Transmission Electron Micrograph (TEM) of T-bacteriophage viruses attacking a bacterial cell of Escherichia coli. Seven virus particles are seen (blue), each with a head and a tail. Four of these are “sitting” on the brown bacterial cell and small blue “tails” of genetic material (DNA) are seen being injected into the bacterium. T-bacterio- phages are parasites of bacterial cells. The virus attaches itself to the cell’s wall and, using it’s tail as a syringe, injects it’s own DNA into the bacterium. The virus DNA then takes over the bacterial cell, forcing it to produce more viruses. Magnification: x63,000 at 5x7cm size.
Credit: EYE OF SCIENCE/SCIENCE PHOTO LIBRARY
4 months ago
Credit: P. HAWTIN, UNIVERSITY OF SOUTHAMPTON/ SCIENCE PHOTO LIBRARY
Caption: Helicobacter pylori. Coloured transmission electron micrograph (TEM) of a Helicobacter pylori bacterium (formerly known as Campylobacter pyloridis). This Gram-negative bacillus bacterium is curved (as here) or spiral in shape, with flagellae for motility. Here, many hair-like flagellae are visible. Colonies of H.pylori occur on the stomach mucous membrane in people suffering gastritis, and this bacteria has been linked to stomach ulcer formation. H.pylori may also be a co-factor for gastric cancer; its presence increases the risk of stomach tumours. Magnification: 7,700 at 6x4.5cm size.
10 months ago