CELLS alive! Library: Contents of Volume 1

1.1 Streptococcus pneumoniae Speed x 540

Strep (aka Pneumococcus) that can cause ear infections and pneumonia are becoming resistant to antibiotics. This growth is shown at 540 times real speed.

1.2 Streptococcus pyogenes (Group A, beta-hemolytic)

Organisms taken from patient with necrotizing fasciitis, these bacteria are sometimes called "flesh-eating bacteria" - can be fatal in occasional cases. Shown growing time-lapse in culture.

1.3 Necrosis in neutrophil eating leukotoxic Strep

Streptococcus pyogenes (Group A, beta-hemolytic) have toxins on their surface that can lyse red blood cells and can also lyse white blood cells. The white cell is eating these Strep and both kills the bacteria and is killed by the bacteria.

1.4 Apoptosis in human neutrophil.

Apoptosis, also called "programmed cell death", is a process inherent in many cells of the body. In the embryo, hands start as "paddles" until cells between prospective fingers die by apoptosis. Apoptosis has been triggered in this white blood cell by turning off the cell's protein synthesis. Neutrophils are produced constantly in the marrow and leave to circulate in the blood. After 24 hours they undergo apoptosis and are eaten by other body cells.

1.5 Penicillin killing E. coli

Penicillin kills bacteria by interfering with the bacteria's cell wall production. The cell wall weakens and the bacterium bursts.

1.6 Chemotaxis of human PMN

White blood cells "smell" bacteria and move toward the smell by the process called "chemotaxis".

1.7 Neutrophil ingesting E. coli

This white blood cell is eating a common intestinal bacterium, Eschericia coli. White cells eat bacteria and kill them by a variety of methods including oxidative activity, production of hydrogen peroxide, and special antibiotics.

1.8 The capsule of Strep pneumo (Pneumococcus)

Besides being resistant to some antibiotics, Stretococcus pneumoniae has a slippery capsule on its surface that can be seen when the bacteria are suspended in India Ink.

1.9 The capsule of Strep pneumo

Besides being resistant to antibiotics, Strep pneumo's capsule is slippery and helps the bacteria avoid being eaten and therefore killed by white cells.

1.10 Neutrophil oxidative burst - NBT

One important method of killing employed by white cells is the oxidative burst. The white cell produces an anti-bacterial compound called "superoxide anion" and the production can be visualized by the use of a dye - nitroblue tetrazolium (NBT).

1.11 Human culture-derived macrophage eating Candida albicans

Another white cell type, the macrophage, lives longer than neutrophils, sometimes inhabiting body tissues, and is here shown eating a pathogenic fungal (yeast) cell, Candida albicans.

1.12 Cytotoxic T lymphocyte killing influenza-infected target

Lymphocytes can "learn" to recognize cells that are infected with viruses or that are cancerous. They attack and kill these cells. The smaller cell is the T cell, the larger one the infected cell. T-cells are the ones that drop in number in people with AIDS.

1.13 Giardia lamblia

Water-borne parasite that often infects wild/domestic animals and can infect humans that drink from streams/wells. Giardiasis also called "beaver fever" is the disease caused by Giardia in the intestine, sticking onto the intestinal wall and sometimes coating the surface. Results in weight loss.

1.14 Excystation of Cryptosporidium parvum

Another water-borne pathogen - cysts can be found in some public water supplies. Takes only 4-6 to infect. You drink the water, the cyst passes the stomach where acid weakens the cyst wall, and in the intestine, the little caraway seed-like sporozooites invade the intestinal wall and produce more cysts. Sporozooites are shown escaping their cysts. Can be fatal in suppressed immune individuals like AIDS.

1.15 Entamoeba histolytica

Water-borne, free-living parasite, causes amoebic dysentery and invasive liver abscesses.

1.16 Entamoeba histolytica lysis of human neutrophils

Though much smaller, white blood cells will attack Entamoeba. But toxin(s) on the ameba's surface bursts the white cells on contact. Wave after wave of white cells are shown exploding on contact.

1.17 Human neutrophils mobbing and killing Trichomonas vaginalis

White cells gang up on this vaginal parasite and actually tear it into pieces.