Introduction
Airborne microbes are biological airborne contaminants
like bacteria, viruses or fungi as well as airborne toxins passed from one
victim to the next through the air, without physical contact, causing
irritation. This usually happens when an infected subject sneezes, coughs, or
just plain breathes. It is hard to prevent such a method of transmission.
Airborne microbes are a major cause of respiratory ailments such as allergies
and pathogenic infections (virus or bacteria).
The human microbiota is the aggregate of
microorganisms, a microbiome that resides on the surface and in deep layers of
skin (including in mammary glands), in the saliva and oral mucosa, in the
conjunctiva, and in the gastrointestinal tracts. They include bacteria, fungi,
and archaea. Micro-animals which live on the human body are excluded. The human
microbiome refer to their genomes. One study indicated they outnumber human
cells 10 to 1[citation needed]. Some of these organisms perform tasks that are
useful for the human host. However, the majority have been too poorly
researched for us to understand the role they play, however communities of
microflora have been shown to change their behavior in diseased individuals.nThose
that are expected to be present, and that under normal circumstances do not
cause disease, but instead participate in maintaining health, are deemed
members of the normal flora.
Healthy people live in harmony with most microorganisms
that establish themselves on or in (colonize) the body. The microorganisms that
usually occupy a particular body site are called the resident flora. Cells of
the resident flora outnumber a person's own cells 10 to 1. Microorganisms that
colonize people for hours to weeks but do not establish themselves permanently
are called transient flora.
The resident flora at each site includes several
different types of microorganisms. Some sites are normally colonized by several
hundred different types of microorganisms. Environmental factors such as diet,
sanitary conditions, air pollution, and hygienic habits influence what species
make up a person’s resident flora. If transiently disturbed (for example, by
washing or use of antibiotics), the resident flora usually promptly re-establishes
itself. Rather than causing disease, the resident flora often protects the body
against disease-causing organisms. However, under certain conditions,
microorganisms that are part of a person’s resident flora may cause disease.
Such conditions include the use of antibiotics and a weakened immune system (as
occurs in people with AIDS or cancer, people taking corticosteroids, and those
receiving chemotherapy). When antibiotics used to treat an infection kill a
large proportion of certain types of bacteria of the resident flora, other
resident bacteria or fungi can grow unchecked. For example, if women take
antibiotics for a bladder infection, the antibiotics kill some of the resident
flora, allowing yeast in the vagina to multiply and cause a vaginal yeast
infection.
Some microbiota are considered
transient, as they can be only isolated and cultured from skin samples from
time to time. These are mainly Gram positive bacteria, including clostridia in
the perineal area. Occasionally, moist areas allow the growth of Gram-negative
acinetobacter. Other Gram-negative bacteria are not considered part of the
normal skin micobiota, as the relatively low humidity and high osmotic pressure
of the skin are unfavourable for their growth.
Objective
To determine the microorganisms in the air and from healthy humans.
Materials and reagents
Molten nutrient agar
Sterile water
Sterile petri dishes
Sterile clinical swab
Pipette and tips
Discussion
Microorganisms populations grow extremely fast under the desired nutrients and environmental conditions.Since bacteria were first cultured on solid media, describing the appearance of bacterial colonies has been an important tool for microbiologists. Observing colony morphology is a tool used by clinical microbiologists, in particular, and descriptions of colonies are often found in the primary literature. Distinguishing colony morphology is one of the first skills taught to microbiology students. Different types of microorganism will produce colonies that are distinctive in appearance such as form, elevation, sizes, surface,texture and color. The microorganisms are classified according to their structural and functional attributes by referring to the Bergey’s manual. It is the reference manual that can identify different type of microorganisms and their physical appearance that leads to the determination of a microorganisms type.
A few basic characteristics of colony morphology is used to differentiate the microorganisms:
In this experiment, all these aspects are studied. The differences between self made and commercial agar are compared and contrasted based on the morphology of the colonies.
Air
Elevation: Raised
Size: Small
Surface: Shiny, smooth
Texture: Moist
Color: White and opaque, pale yellow
Margin: Entire
The air almost always contains microorganisms, but their numbers vary depending on weather, time of day, season and location in the outdoors, and on sources and activity indoors. In this experiment, the culture media exposes to the air in the laboratory contains low concentration of contaminants. The most common genera of fungi in indoor air are Penicillium Aspergillus. For bacteria, the common genera found in indoor air are Staphylococci, Bacillus and Clostridium.
Ear
Form: Circular, Irregular
Elevation: Raised
Size: Small
Surface: Shiny and smooth
Texture: Moist
Color: Yellow and white opaque
Margin: Entire
The ears are the external part of our body thus exposed more to the microbes in the outside environment. Some of the most common bacteria are Staphylococcus epidermis, Turicellaotitidis, Alloiococousotitis, Pseudomonas aeruginosa, Corynebacterium, Staphylococcus aureus, and Streptococcus saprophyticum. The most common fungal microbe known to reside in the ear is Candida albican.
Hands
Form: Circular, Irregular
Elevation: Raised, flat
Size: Large, small
Surface: Shiny and smooth, Dull and Rough
Texture: Dry
Color: White opaque, Buff yellow
Margin: Entire, Undulate
The hands commonly contains many microbes since we often touch the surfaces of various things without realizing it. Moreover, our fingernails can trap the bacteria. Most of bacteria are harmless but once it enter our body, it might cause diseases. The main pathogenic bacteria which are more likely to be found on the hands are Staphylococcus, Corynebacteria, Streptococcus, Myobacteria, and Haemophilus.
Normal Breathing
Form: Circular, Irregular
Elevation: Raised, flat
Size: Small
Surface: Shiny and smooth
Texture: Moist
Color: White, pale yellow
Margin: Entire, Undulate
Our mouth contains pathogenic and non-pathogenic microorganisms. The pathogenic bacteria will cause some microbial diseases of the respiratory system which may occur in the upper or lower regions. Some examples of these non-pathogenic bacteria are Streptococcus, Neisseria, Haemophilus, and Micrococcus. Whereas the pathogenic bacteria might cause strep throat, scarlet fever, diptheria. The pathogenic bacteria are Corynebacterium diphtheriae, Streptococcus pyogenes,Staphylococcus aureus and Streptococcus pneumoniae.
Violent Coughing
Form: Circular, Irregular
Elevation: Raised, convex
Size: Small, Large
Surface: Shiny, smooth
Texture: Moist, Dry
Color: White opaque, Pale yellow
Margin: Entire, Undulate
It can be seen that violent coughing have many microbes than normal breathing even they are originated from the same place. It is because the microbes are forced to come out through violent coughing since a cough is a sudden and often repetitively occurring reflex which helps to clear the large breathing passages from secretions, irritants, foreign particles and microbes. Actually the microbes during breathing and coughing are quite similar because there are originated from the same place, mouth and nose cavity in human beings. The species of Staphylococcus most often found in the mouth include Staphylococcus epidermidis and Staphylococcus aureus. Streptococcus mutans, Streptococcus mitis, Streptococcus salivarius, Streptococcus pneumoniae and Streptococcus pyogenes all live in the mouth. Lactobacillus bacteria also present in mouth. While most of the rod-shaped E.coli in the body is located in the intestines, a small amount of the bacteria is present in the mouth.
Conclusion
From this experiment we are able to determine several types
of microorganism present in the air and from healthy human. Furthermore, it can
be concluded that microorganisms are able to survive everywhere as long as the
surface are suitable for their growth. This is because there are no significant
differences between the microorganisms in both the self-made and commercial
nutrient agar. It also shows that both nutrient agars are compatible with
various common microorganisms.
In addition, from the growth of different colonies in each of
the petri dishes the morphologies of microorganisms are observed and studied. Likewise, it can be suggested that microorganisms
are more abundant outside the human body compared to the inner part as the size
of colonies formed on the petri dishes coming from the samples outside are
mostly bigger.
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