Bacteria are small organisms that cannot be
seen with the naked eye. To detect them,
one must use a microscope. A bacterium
is made up of a cell wall which is a rigid
layer made of proteins and sugars that
defines the borders of the cell, provides it
with physical support, and protects it from
the environment, that surrounds the genetic
material and other structures that are needed
for the bacterial cell.
Bacteria are the most abundant form of life
on our planet. They exist in multiple sizes,
shapes, and colors. Bacteria reproduce by
division, where each cell divides into two
new cells, called daughter cells. Within half
an hour or so, bacteria can double in number.
Many bacteria are not harmful to humans
and are considered "good" bacteria. These
good bacteria are beneficial to humans. For
example, "good" bacteria can take up the
space of harmful bacteria and by doing so
protect us from infections. Other bacteria
help us to digest our food. Harmful bacteria,
also called pathogenic bacteria, cause
various illnesses.
Bacteria live in colonies, in which each
bacterium is surrounded by many other
bacteria that protect it from the external
environment. Within the colony, the
bacteria communicate with each other
using chemicals. These chemical signals
help the bacteria to form a network called
a biofilm. Another name for a biofilm is a
plaque. The term plaque is often used by
dentists to describe the bacterial layer on
teeth. This layer is well attached to the
teeth and secretes materials that destroy
the teeth. A biofilm can provide bacteria
with resistance to antibiotics, which
can usually kill individual bacteria. As
a biofilm, some bacteria can still live,
multiply, and cause infections even in the
presence of antibiotics. These infections
are a major problem in hospitals. To
prevent these infections, hospitals and
the healthcare system invest much effort
to clean hospital facilities and medical
devices.
Unfortunately, an ultimate solution that
completely prevents biofilm formation
does not exist. Research groups that try
to crack the problem of biofilms have
come up with several different solutions,
but there is still a need for a coating that
will be stable enough, will not come
off from the surface, will not be toxic
to cells, and will be easy to apply and
inexpensive.
