Human Pathogens

Many different
microorganisms can be
human pathogens. (a) Human
immunodeficiency virus (HIV), the
cause of AIDS. (b) Influenza virus.
(c) Staphylococcus aureus, a bacterium
that colonizes human skin, is the
common cause of pimples and boils,
and can also cause food poisoning.
(d) Streptococcus pneumoniae, is the
major cause of pneumonia and is
also a common cause of meningitis
in children and the elderly.
(e) Salmonella enteritidis, the bacterium
that commonly causes food poisoning.
(f) Mycobacterium tuberculosis, the
bacterium that causes tuberculosis.
(g) A human cell (colored green)
containing Listeria monocytogenes
(colored yellow), a bacterium that can
contaminate processed food, causing
disease (listeriosis) in pregnant women
and immunosuppressed individuals.
(h) Pneumocystis carinii, an opportunistic
fungus that infects patients with acquired
immunodeficiency syndrome (AIDS) and
other immunosuppressed individuals. The
fungal cells (colored green) are in lung
tissue. (i) Epidermophyton floccosum,
the fungus that causes ringworm.
(j) The fungus Candida albicans, a normal
inhabitant of the human body that
occasionally causes thrush and more
severe systemic infections. (k) Red blood
cells and Trypanosoma brucei (colored
orange), a protozoan that causes
African sleeping sickness. (l) Schistosoma
mansoni, the helminth worm that causes
schistosomiasis. The adult intestinal blood
fluke forms are shown: the male is thick
and bluish, the female thin and white.
All the photos are false-colored electron
micrographs, with the exception of (l),
which is a light micrograph.