j. Septic. Septic refers to something that is affected by pathogens, their toxins,
or to something putrid.
k. Septicemia. Septicemia refers to the widespread distribution of infective
bacteria through the bloodstream. It is also called "blood poisoning."
l. Sterile. Sterile means free from live pathogens and other live
CLASSIFICATION OF PATHOGENS
a. Infectious Agents. Infectious (pathogenic) agents of one kind or another are
everywhere that life exists. They inhabit the air, soil, and water. In the body of humans
and animals, they inhabit waste products, skin, respiratory tracts, and alimentary tracts.
Agents capable of harming man include bacteria, viruses, and fungi. The primary basis
for the development of infection is the growth of bacteria within the wound itself. All
injuries in which the skin has been penetrated are contaminated by bacteria. Following
are some of the types of pathogens.
(1) Bacteria. Bacteria are microscopic one-celled plant organisms. The
group names sometimes describe the infection. The most common are named below.
(a) A staphylococcus is a pyogenic (pus-producing), spherical-shaped
form of bacteria. It is the most common cause of localized infection in which pus is
(b) Streptococcus is also a pyogenic, spherical-shaped form of
Bacilli is a term applied to rod-shaped bacteria.
(2) Viruses. Most viruses are very small microscopic protein bodies. They
are neither plant nor animal. Viruses are capable of multiplying only in the presence of
living cells and are normally separated into subgroups according to the type of host they
infect--bacterial viruses, animal viruses, and plant viruses.
(3) Fungi. Fungi are a low order of plant life that lack chlorophyll, such as
toadstools, yeast, and molds. An example of a condition caused by a fungus is athlete's
foot (tinea pedis).
b. Development of Infection. Bacteria multiply and increase in numbers very
rapidly; however, wounds of less than 4 hours old are considered to contain bacteria
that have not begun to grow. Those wounds from 4 to 8 hours old are known to contain
bacteria that are actively growing in the tissues on the surface or in the depths of the
wound. In injuries more than 8 hours old, the bacteria have usually invaded adjacent