Lab 4 Report by Yi Lee
Name: Choong Yi Lee
Matrix Number: 111359
Matrix Number: 111359
Lab 4: SOURCES
OF CONTAMINATION AND INFECTION
Introduction
Air borne microorganisms are usually carried on dust particles, although
some (fungal spores, for example) can be carried directly by air currents. It
is important for microbiologist to be aware of the potential for contamination
by airborne microorganisms. Carefully observation of simple precautions
dramatically reduces the risks of contamination.
Every human is colonized by billions of microorganisms. These
microorganisms, some of ehich are vital to our wellbeing, constitute our
resident or normal microflora. Resident microorganisms are nourished by the chemicals and moisture
excreted by the human bod. In moist areas such as the armpit, there may be one
million bacteria per cm3 ; on the drier skin of the forearm, there may be 10000
bacteria per cm3 ! ! !
Resident microorganisms are either nonpathogenic or are prevented from
infecting the body by an array of mechanical and chemical defences. Some resident
microbes are, however, opportunistic pathogens which may cause infection if the
body’s defences are breached-for example, if the skin is broken.
Transient microorganisms are picked up from our environment-for example
from faecal contact or from soil- and usually fail to become permanent skin
residents. One of the most important reasons for failure to gain permanence is
that the established residents are better able to compete for nutrients. Since
transients generally originate in other environments, they are poorly adapted
to conditions on the skin and usually disappear within 24 hours of arrival.
Microorganisms in the upper respiratory tract are either normal
residents or transients. As with the
skin, the normal microflora largely consists of non pathogens or opportunistic
pathogens.
Large numbers of transients enter upper respiratory tract as we breathe
or eat. They may also come from our own hands or from improper sanitation during
food preparation. Regardless of their origin, most transients are nonpathogenic
and are quickly killed by various defences arrayed against them.
Objective
To
determine the microorganisms in the air and from healthy humans
Results
Colonies of ears
Colonies of Air
Colonies of Hands
Colonies of Normal Breathing
Colonies of violent cough
Discussion
Airborne particles
are a major cause of respiratory ailments of humans, causing allergies, asthma,
and pathogenic infections of the respiratory tract. Airborne fungal spores are
also important agents of plant disease, and the means for dissemination of many
common saprotrophic (saprophytic) fungi.
We always
have a certain amount of bacteria on our hands. Usually the bacteria are
adapted to living on human skin and are harmless or symbiotic, since they help
to defend against harmful bacteria. Every
day our hands come into contact with millions of micro-organisms called
bacteria. Given plenty to feed on and some warmth the bacteria will grow and
can actually be seen. Staphylococcus
aureus is the most common bacteria found in the nose and on hand. Staphylococci
are perfectly spherical cells about 1 micrometer in diameter. The staphylococci
grow in clusters because the cells divide successively in three perpendicular
planes with the sister cells remaining attached to one another following each
successive division. It is clear that our hands occupy by bacteria and for
personal hygiene, we must always wash our hands with a correct way.
The
human ear is comprised of 3 main parts: outer, middle, and inner. The outer ear
consists of the pinna(the visible part of the ear) and the auditory ear canal
to the tympanic membrane(ear drum). Because it is exposed to the outside environment, despite the best
efforts of the ceruminous glands, the healthy outer ear still houses a variety
of microbes. Some of the most common bacteria areStaphylococcus epidermis,
Turicellaotitidis, Alloiococousotitis, Pseudomonas aeruginosa, Corynebacterium,
Staphylococcus aureus, and Streptococcus
saprophyticum. The most common fungal microbe known to reside in the ear is Candida albicans .Under normal circumstances, this
bacterial flora does not thrive.Microbes that are known to inhabit the middle
ear are Streptococci,
Haemophilus pneumoniae, Moraxella catarrhalis, and less commonly Mycobacterium. These bacteria
are known to get to the middle ear by migrating through the nasophraynx and
Eustachian tube. Because of the blood-labyrinth barrier and the presence of
immunoglobulins in the inner ear fluids there should be virtually no microbes
living normally in the inner ear.
There
are many microbes in our nose, trachea, bronchus and alveolus. The inhalation
and exhalation of the air contain Staphylococcus. Alveolus contains a lot of air sac which is used
for diffusion of air to our lungs. The surface of alveolus also moisture and it
contain microbes. The moisture of alveolus enable the process of diffusion of
inhale air become faster so that we can get always get the fresh air. Because
of the microbes in alveolus, it is not curious to know that the breathing air
also contain a lot of bacteria.
Violent coughing
is a reflex action started by stimulation of sensory nerves in the lining of
the respiratory passages - the tubes we use to breathe. When a person coughs,
there is a short intake of breath and the larynx (the voice box) closes
momentarily. Coughing usually means there is something in the respiratory
passages that should not be there. This can be caused by breathing in dust
particles in the air or when a piece of food goes down the wrong way. Infections
in the breathing tubes can be caused by both bacteria and virus. Bacterial pneumonia is an infection caused by
the presence of bacteria within the lungs. The most common cause of this type
of infection is a bacterium called streptococcus pneumonia. Bacteria within the lungs can irritate and
inflame the sensitive tissues of a patient's airway. When this occurs, patients
with this infection can develop a dry, chronic cough. Depending upon the severity of this infection, affected
patients may progressively develop a congested cough that yields mucus or
phlegm. Patients who begin to cough up mucus that contains blood require
immediate medical attention.
http://www.formulamedical.com/topics/head&neck/inner%20ear%20infection%20labyrinthitis.htm
http://www.sciencedaily.com/releases/2010/06/100621173918.htm
http://www.sciencedaily.com/releases/2010/06/100621173918.htm
Conclusion
It is found that many airborne microorganisms in the air from a healthy human body. For a good personal hygiene, we must keep ourselves clean especially hands because hands is the one always keep contact with things.
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