CNRI / SCIENCE PHOTO LIBRARY CNRI / SCIENCE PHOTO LIBRARY
False-colour scanning electron micrograph (SEM) of the Gram-positive bacteria Streptococcus pneumoniae (the pneumococcus), a cause of pneumonia in humans. The spherical bacteria secrete a viscous material to form a capsule around their call wall. The role of the capsule is uncertain, but is associated with virulence in pathogenic organisms. It gives the bacteria protection against the immune system of an invaded host (animal or human). Capsulated organisms resist phagocytosis (engulfing) by scavenging macrophages and are thus able to continue to multiply. Magnification x2000 at 6x7cm size.
Model release not required. Property release not required.