red blood cells illustration of microscopic photos
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.
Listeria sp., a genus of aerobic, non-sporing, Gram-positive bacteria. The bacterium in centre of image is undergoing division by binary fission. L. monocytogenes causes disease in man, usually meningitis or septicaemia, which affects neonates (premature babies), the elderly, chronically sick, or persons taking immunosuppressive drugs. Neonatal cases arise through the asymptomatic carriage of the bacteria in the vagina by the mother. Listeria infections usually respond to treatment with ampicillin and gentamicin