Importance of microflora in zooanimals
What is Microflora?
living microorganisms that are so small that they can be seen only with a microscope and that maintain
a more or less constant presence in a particular area
e.g. the pharynx or the rumen, includes bacteria,
viruses, protozoa, fungi .
Microflora is the mixture of microorganisms
that are regularly found at any anatomical site of human body.
In human microflora
elementary tract, urogenetal tract, ears, mouth (i.e oral cavity), nose (I.e
respiratory tract) and eyes
The microflora of the digestive tract
Human stomach has small number of bacteria because of the
high acidity of stomach. However,certain bacteria can survive in stomach, for
example, Helicobacter pylori who was
discovered in human stomach in 1980’s. Recently known that this bacteria is the
cause of peptic ulcer and gastritis.
Human small intestine have small number of bacteria i.e. Streptococci, Lactobacilli and also yeast (Candida
albicans). In the lower part of small intestine, ileum (is a part at the
junction of small intestine and large intestine), Microflora are present in
bigger number as compared to first part of small intestine.
contains a great variety of bacteria. Colon in the middle part of large
intestine and bacteria reside in it. The species of bacteria which reside there
are Bifidobacterium, Coliforms (E. coli), Bacteroides, Eubacterium, Lactobacillus, Clostridium and Streptococcus. About 20% of feces consist
of bacteria in a normal person. These bacteria come from the last part of large
digestive tract of herbivores:
From herbivores, we discuss cow because cow is a ruminant. Cows are not the only ruminant animals. Examples of other
ruminants are gazelles, giraffes, moose, antelope, caribou, sheep, goats, and
deer. Herbivores are animals that eat plants like kangaroos, llamas and camels
have modified stomach similar to rumens.
Rumen is a home for billions and billions of microbes that
include bacteria, protists, fungi and some viruses. Microbes of rumen are
different from complex microbe organisms that assist one another to help in the
digestion of food.
Hay is eaten by ruminants like cow. It is made up of
cellulose and polymers of long molecules that the animal cannot digest.
Microbes can help in digestion of these cellulose and polymer molecules. They
break down the cellulose and polymers into small catabolic bits which the cow
can digest and absorb. Microbes play this activity by special enzymes to
convert cellulose into small digestable particles.
Microflora of the respiratory tract:
upper part of respiratory tract is a habitat for a large number of species of
bacteria so upper respiratory tract lacks ciliated epithelium which help in
cleansing action. For instance, nostrils are a colony of enourmous number of
bacteria i.e. Staphylococcus
Microbes of the Skin:
Epidermis of the skin of human is not a fertile region for
microorganisms to live because skin surface is dry and acidic upto a little
extinct while microbes require moist region for their proper growth. For
instance, Propionibacterium acne
and the Staphylococcus epidermidis.
Microflora of the Nostrils:
Nostrils are moist due to the presence of mucus inside and it
becomes a habitat for Gram-positive bacteria i.e. Staphylococcus aureus.
There are many dissimilar types of kinship that the body can
induce with the microflora. These are:
It is a “mutual benefit”, as both organisms get benefit from
association from each other. For instance, E. coli synthesize and secrete
vitamin K and B12 which is profitable for host. In return, E. coli gets warm
& nutrient and moist rich environment for its better survival.
In this type of association, one organism gets benefit while
the other is neither benefited nor harmed. Bacteria have no commensalism
relationships with human beings. If bacteria present in our body or on the
body, they play a role which is either beneficial (antagonism of microbes) or
E. coli is present in the digestive tract of human and other
organisms where it causes no harm and consequently no disease. But when it
enters into the urogenital tract of organisms, it may be harmful (pathogenic).
aureus is a bacterium of nose microflora found in the upper portion
of respiratory tract. If it gains entry into the cells by any wound or bleeding
or burn it becomes harmful may be pathogenic.
Major characters of microflora are given below:
Not disease causing:
Microflora are present inside the body and also on the body.
They do not induce diseases in the healthy animals.
Very enourmous in number:
Microflora are very abundant in number. They are present in
living organisms abundantly. For example, a healthy human has about 1013 body
cells but microflora individuals are approximately 1014 in human body. One
fourth of feces contain bacteria.
Found externally to the body:
Mostly, microflora are found on external surface to the body
as on the skin, in the surroundings of eyes, in nose, in throat and also found
on internal surfaces as lower parts of
urethra and in large intestine.
Benefits of microflora:
Preventing colonization by microbial
anatgonism competing with nutrients and space and produce toxic condition or
environmental condition to keep harmful pathogens away (acidity in vagina).
Develop immune system by keeping it
active by providing antigens.
Microflora are essential for us to survive.
They gain their food from the stuff in our pie hole.
If colonies of bacteria are worn out by poisons or
antibiotics, they must be replaced otherwise we would die ultimately.
They provide a host defence mechanism by taking control on ecological
niches for bacteria, e.g. the intestinal villi.
Bacteria produce and excrete various compounds like vitamin B12 and
vitamin K in the intestine which are important nutrients for host.
The oral microflora assists in immunity through inducing low level of
circulating and secretory antibiotics that kill pathogens. In other words, they
enhance body’s immunity.
The oral bacterial flora kill nonindigenous species by producing
inhibitory fatty acids, peroxides and bacteriocins (it is a protein and bacreria produce it,
it helps in stamping and killing microbes).
Microflora help to digest food as they break down
foodstuffs that are normally indigestible by the host into forms that are
easily digestible by the hosts.
The Microflora protects the host from infection by
harmful pathogenic organisms.
They produce antibacterial substances as by product of
metabolism, so they have a local antibiotic effect which retard the attack of
invaders on host.
They stimulate an immunological response (an
antibody-mediated immune response) as they act as antigens in the human body.
Disadvantages of microflora:
Microflora is harmful when overgrown (i.e. use of antibiotics) and
misplaced (i.e. urinary tract flora may placed with facel flora).
Microflora may also cause disease in following conditions:
If individual become immunocompromised.
If he change his anatomical location as usual.
There are few limitations of microflora to the human body as
well. For example, most of the microflora are pathogens and may cause
infectious diseases. Similarly, if microflora take control on certain tissues,
they can cause infection as well as destruction. Likewise, the Microbe may
absorb some of the hosts nutrients due to competition, leading to the
development of bacterial antibiotic resistance in humans.