Name: Yu Tiam Meng
Matric card no.: 111437
Lab 4: Sources of Contamination and Infection
Introduction
Airborne microorganisms are usually carried on dust particles, although some may be carried directly by air currents (for example,fungal spores). It is important for microbiologists to be aware of the potential for contamination by airborne microorganisms. Carefully observation of simple precaution reduces the risk of contamination of the cultures.
Every human is colonized by billions of microorganisms. These microorganisms, some of them are vital to our wellbeing, constitute our resident or normal microflora. Resident microorganisms are nourished by the chemicals and moisture excreted by the human body. In moist areas such as armpit, there may be one million bacteria per cm^3; on the drier skin of the forearm, there may be 10000 bacteria per cm^3.
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 are largely consists of nonpathogen or opportunistic pathogens.
Large numbers of transients enter the upper respiratory tract as we breathe or eat. They may also come from our own hands or 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
1) Colonies in air :
2) Colonies of hands :
3) Colonies of ear:
4) Colonies of normal breathing :
5) Coloniesof violent coughing :
Discussion
Sources Of Contamination :
1. Air:
Air
contains
microorganisms. There are vegetative cells and spores of bacteria,
fungi and algae, viruses and protozoan cysts. Since air is often exposed
to
sunlight, it has a higher temperature and less moisture. So, if not
protected form desiccation, most of these microbial forms will die. Air
is mainly it transport or dispersal medium for
microorganisms. They occur in relatively small numbers in air when
compared with
soil or water. The microflora of air can be studied under two headings
outdoor
and indoor microflora.Outdoor microflora:
The air in the atmosphere, which is found outside the buildings, is referred to as outside air. The dominant microflora of outside air are fungi. The two common genera of fungi are Cladosporium and Sporobolomyces . B e s i d e s t h e s e t w o g e n e r a , other genera found in air are Aspergillus, Alternaria, Phytophthora and Erysiphe . The outdoor air also contains basidispores, ascopores of yeast, fragments of mycelium andconidia of molds. Among the bacterial genera Bacillus and Clostridium, Sarcina , Micrococcus , Corynebacterium and Achromobacter are widely found in the outside air. The number and kind of microorganisms may vary from place to place, depending upon the human population densities.
Indoor microflora:
The air found inside the building is referred to as Indoor air. The commonest genera of fungi in indoor air are Penicillium , Aspergillus. The commonest genera of bacteria found in indoor air are Staphylococci, Bacillus and Clostidium. In case of occupants being infected, The composition shows slight variations with latitude and to a lesser extent with altitude. The ozone owes its existence in the atmosphere to photosynthesis from oxygen under the influence of solar ultraviolet radiations.
2.Normal breathing
Microscopic organisms are living inside our nasal passageways. Although
most of these bacteria are non-pathogenic, some may induce illness if
they successfully break through the bodies defense systems. Some
examples of these non-pathogenic bacteria are Streptococcus, Neisseria, Haemophilus, and Micrococcus. Some of the pathogenic examples include Staphylococcus aureus, Corynebacterium diphtheriae, Streptococcus pneumoniae, and Haemophilus influenzae among others.
3.Ears
Cerumen
or ear wax present in outer ear traps number of microorganisms and
prevent them from entering into inner ear. Cerumen also contains
antimicrobial compounds which discourage growth of pathogenic
Pseudomonas aeruginosa and Staphylococcus aureus, otherwise outer ear
being moist and warm would have been ideal place for microbial growth.
Despite Cerumen, external ear contains Staphylococcus epidermidis,
Propionibacterium acnes and α-hemolytic streptococci as normal flora.
Internal ear, under normal healthy state of individual is free from any
microorganisms; reason is that it is closed by membranes and filled with
lymph fluid. Middle ear microflora matches microbes of nasopharynx as
nasal microorganisms can enter middle ear via Eustachian canal. Otitis
media, an infection of middle ear is caused by Haemophilus influenzae
received from nasopharynx region.
4.Hands
There are many species within these genera that can be located within the fingernails, such as Staphylococcus epidermis and aeureas or Candida albicans, parapsilosis, and instaniae. These are a select few of the many microbes that can survive on human hands and nails.
The hands and fingernails are often affected by fungal and yeast infections, such as those caused by species of Trichophyton and Candida. In particular onychomycosis (nail infection) is the most common disease associated with the hands and feet, effectuating at least 50% of all fingernail infections. [8] Onychomycosis is caused by dermatophytes (infectious fungi or yeast) invading the nail bed, which also cause ringworm and tinea, such as athletes foot. [9] Most cases of onychomycosis is characterized by mild inflammations, resulting in the nail bed becoming cornified and losing its normal contour. Another form of onychomycosis results in the destruction of the nail plate and is often visible by a whitish yellow discoloration. Onychomycosis can also occur on the external nail plate, caused by an invasion of Acremonium and Aspergillus, which infect the superficial layers of the nail resulting in white patches on the nail. [8] Onychomycosis is increasingly viewed as a major medical concern as these infections can lead to secondary infections as well as being transferred to other bodily areas and other people. Fungi and yeasts are also a major concern for individuals with artificial nails. Artificial nails weaken the natural nail and can also cause the natural nail to lift from its base which expose the fingers to bacteria and fungi that can grow between the two nails.[10] These condition substantially increase the risk of onychomycosis and other related diseases. Thus, as mentioned earlier, natural nails are the best for fingernail health care.
5.Violent couching :
Actinomyces,
Bacteriodes, Micrococcus, Enterococcus, Bordetella, Corynebacterium,
Fusobacterium, Haemophilus, Lactobacillus, Mycobacterium, Neisseria,
Peptococcus, Staphylococcus, Streptococcus, Treponema, Klebsiella,
Enterobacter, Lactobacillus, Escherichia, Proteus and Veillonella
constitute normal flora of throat. Species of some bacteria may turn
opportunists provided favorable conditions are emerged; Staphylococcus
aureus, S. pneumoniae, S. pyogenes, Bordetella pertussis, Haemophilus
influenzae, Mycobacterium gordonae, Neisseria meningitides, Actinomyces
israelli, Streptococcus viridians, Corynebacterium diphtheriae,
Fusobacterium necrophorum and Bacteriodes coagulans are some of the
opportunistic pathogens present in a throat as microflora. Classical and
infant meningitis infections caused by N. meningitides and H.
influenzae respectively and whopping cough (B. pertussis), diphtheria
(C. diphtheriae) are initiated in throat. Lung infectious agents such as
Pseudomonas aeruginosa (blue pus infection), K. pneumoniae,
streptococci (sinusitis) are passed via throat. β- Hemolytic
streptococci responsible for tonsillitis are predominant among
opportunistic normal flora. During tonsillitis, they not only infect
throat and tonsils but also cause ear infections via Eustachian tube.
Conclusion
We must be careful about the microorganisms because microorganisms that can potentially cause disease are spread in three main ways: by direct contact (by touching someone else – holding hands, hugging etc.), through the air (when we cough, sneeze, talk or sing) and by indirect contact (by touching contaminated surfaces or objects). Eating and drinking contaminated food and water is a major way of picking up food poisoning.
References
NAME:TUNKU SYED ISKANDAR AL-QADRI B.T SYED AZHAR
METRIC NO:111434
Lab 4: Sources of Contamination and Infection
Introduction
Every human is colonized by billions of microorganisms. These microorganisms, some of them are vital to our wellbeing, constitute our resident or normal microflora. Resident microorganisms are nourished by the chemicals and moisture excreted by the human body. In moist areas such as armpit, there may be one million bacteria per cm^3; on the drier skin of the forearm, there may be 10000 bacteria per cm^3.
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 are largely consists of nonpathogen or opportunistic pathogens.
Large numbers of transients enter the upper respiratory tract as we breathe or eat. They may also come from our own hands or 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:
1) Colonies in air :
2) Colonies in hand:
3) colonies in ear:
4)colonies in cough:
5)colonies in normal breathing:
DISCUSSION:
Source of contamination:
1-Colonies in air.
The air in the atmosphere, which is found outside the buildings, is referred to as outside air. The dominant microflora of outside air are fungi. The two common genera of fungi are Cladosporium and Sporobolomyces . B e s i d e s t h e s e t w o g e n e r a , other genera found in air are Aspergillus, Alternaria, Phytophthora and Erysiphe . The outdoor air also contains basidispores, ascopores of yeast, fragments of mycelium andconidia of molds. Among the bacterial genera Bacillus and Clostridium, Sarcina , Micrococcus , Corynebacterium and Achromobacter are widely found in the outside air. The number and kind of microorganisms may vary from place to place, depending upon the human population densities.
In outdoor situations, sunlight (ultraviolet radiation),
ozone, temperature extremes and wind ensure that non-spore microbial
populations (fungi, bacteria, etc) decay and disperse rapidly but indoors,
these factors are controlled for human comfort, resulting in airborne microbes
surviving longer, sometimes even days. Interestingly, bacteria decay faster in
air than viruses apparently because they depend more on moisture for their
survival than do viruses
2-colonies in hand
Hands will be more exposed to bacteria than other skin surfaces, as they touch more 'dirt', but the hand palms have sweat glands to keep the skin surface salty, and that is an unfriendly environment for bacteria.
The influence of hexachlorophane disinfection on the bacterial hand flora of hospital personnel has been examined. Hexachlorophane effectively reduced the total number of bacteria and the staphylococcal carriage. Gram-negative bacilli were isolated from 18·8% of the personnel, and 13% of the carriers continued to carry Gram-negative bacilli for more than six months. The carrier rate was significantly higher among those using hexachlorophane detergents (20·8%) than among those using plain soap (14·1%). Prolonged hand carriage of Gram-negative bacilli was often associated with skin irritation, especially of the nailfolds. Hand carriage may be an important source of Gram-negative infections in hospital, and the increase in these infections may partly be due to extensive use of hexachlorophane preparations.
3-colonies in cough
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. The abdominal and chest muscles used for breathing contract, which in turn increases the pressure needed to drive air out the lungs when the larynx re-opens.
The resulting blast of air comes out at high speed, scrubbing and clearing the airway of dust, dirt or excessive secretions. Coughing is a common symptom when the airways are 'tight', as in asthma.
The cough reflex is a vital part of the body's defence mechanisms. Normally, the lungs and the lower respiratory passages are sterile. If dust or dirt get into the lungs, they could become a breeding ground for bacteria and cause pneumonia or infection in the breathing tubes.
Actinomyces, Bacteriodes, Micrococcus, Enterococcus, Bordetella, Corynebacterium, Fusobacterium, Haemophilus, Lactobacillus, Mycobacterium, Neisseria, Peptococcus, Staphylococcus, Streptococcus, Treponema, Klebsiella, Enterobacter, Lactobacillus, Escherichia, Proteus and Veillonella constitute normal flora of throat. Species of some bacteria may turn opportunists provided favorable conditions are emerged; Staphylococcus aureus, S. pneumoniae, S. pyogenes, Bordetella pertussis, Haemophilus influenzae, Mycobacterium gordonae, Neisseria meningitides, Actinomyces israelli, Streptococcus viridians, Corynebacterium diphtheriae, Fusobacterium necrophorum and Bacteriodes coagulans are some of the opportunistic pathogens present in a throat as microflora. Classical and infant meningitis infections caused by N. meningitides and H. influenzae respectively and whopping cough (B. pertussis), diphtheria (C. diphtheriae) are initiated in throat. Lung infectious agents such as Pseudomonas aeruginosa (blue pus infection), K. pneumoniae, streptococci (sinusitis) are passed via throat. β- Hemolytic streptococci responsible for tonsillitis are predominant among opportunistic normal flora. During tonsillitis, they not only infect throat and tonsils but also cause ear infections via Eustachian tube.
4) colonies in ear
Cerumen or ear wax present in outer ear traps number of microorganisms and prevent them from entering into inner ear. Cerumen also contains antimicrobial compounds which discourage growth of pathogenic Pseudomonas aeruginosa and Staphylococcus aureus, otherwise outer ear being moist and warm would have been ideal place for microbial growth. Despite Cerumen, external ear contains Staphylococcus epidermidis, Propionibacterium acnes and α-hemolytic streptococci as normal flora. Internal ear, under normal healthy state of individual is free from any microorganisms; reason is that it is closed by membranes and filled with lymph fluid. Middle ear microflora matches microbes of nasopharynx as nasal microorganisms can enter middle ear via Eustachian canal. Otitis media, an infection of middle ear is caused by Haemophilus influenzae received from nasopharynx region.
5)colonies in breathing
About 75 to 100 different kinds of germs live in each person's mouth -- of a total of 700 that collectively populate all human mouths, Paster says. Of these, scientists know the names of only about 300.Microscopic organisms are living inside our nasal passageways. Although most of these bacteria are non-pathogenic, some may induce illness if they successfully break through the bodies defense systems. Some examples of these non-pathogenic bacteria are Streptococcus, Neisseria, Haemophilus, and Micrococcus. Some of the pathogenic examples include Staphylococcus aureus, Corynebacterium diphtheriae, Streptococcus pneumoniae, and Haemophilus influenzae among others.
CONCLUSION
as a conclusion,wash hands regularly especially after toilet and before handling food. practice reasonable cleanliness personally and in your surroundings. You also need to make sure you are washing your hands after coughing or sneezing..regardless if it touched your hands or not.. if you are sick..try not to touch other people as much as possible..
NAME:
MUHAMMNAD AIZAT B MAT SAAD
MATRIC
NO: 111385
Lab
4: Sources of Contamination and Infection
Introduction
Airborne
microorganisms are usually carried on dust particles, although some may be
carried directly by air currents (for example,fungal spores). It is important
for microbiologists to be aware of the potential for contamination by airborne
microorganisms. Carefully observation of simple precaution reduces the risk of
contamination of the cultures.
Every
human is colonized by billions of microorganisms. These microorganisms, some of
them are vital to our wellbeing, constitute our resident or normal microflora.
Resident microorganisms are nourished by the chemicals and moisture excreted by
the human body. In moist areas such as armpit, there may be one million
bacteria per cm^3; on the drier skin of the forearm, there may be 10000
bacteria per cm^3.
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 are largely
consists of nonpathogen or opportunistic pathogens.
Large
numbers of transients enter the upper respiratory tract as we breathe or eat.
They may also come from our own hands or 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
Air 1 and 2
Hand 1 and 2
Ear 1 and 2
Normal breath 1 and 2
Coughing 1 and 2
Discussion
All laboratories have contamination problems, and
these problems are unavoidableand largely insurmountable without significant
investment in construction andmaintenance of clean room facilities. Clean rooms
are designed to minimize laboratory contamination.
Microbes found in air in
addition to gases, dust particles and water vapour, air also contains
microorganisms. There are vegetative cells and spores of bacteria, fungi and
algae, viruses and protozoan cysts. Environmental
factors that affect air microflora include atmospheric temperature(There is a
progressive increase in the death rate with an increase in temperature from
-18°C to 49°C ), humidity(Low and high relative humidity cause the death of
most microorganisms) , air current. Air
current is also important in the dispersal of microorganisms as it carries them
over a long distance. In still air the particles with microorganisms tend to settle down. But a gentle air can
keep them in suspension for long periods .
Air is not a medium in which organism grow but is a carrier of
particulate matter ,dust particles,spores ect. Air is mainly transport medium
for microorganisms. They occur in small numbers in air when compared with soil
or water. The microflora of air can be studied under two headings outdoor and
indoor microflora. Air is not a natural environment for microorganisms as it
doesn't contain enough moisture and nutrients to support their growth and
reproduction. One of the most common sources of air microflora is the soil. Microorganisms
found in water may also be released into the air in the form of water droplets and
beside come from plant or animal surfaces. And the main soures of airborne
microorganism is human beings, by activities like coughing, sneezing, talking
and laughing.
The human body contains
a large number of bacteria, most of them performing tasks that are useful or
even essential to human survival. Those that are expected to be present, and
that under normal circumstances do not cause disease, are termed normal flora. It
is estimated that 500 to 1000 different species of bacteria live in the human
body (Sears, 2005). Bacterial cells are much smaller than human cells, and
there are about ten times as many bacteria as human cells in the body. Though
normal flora are found on all surfaces exposed to the environment (on the skin
and eyes, in the mouth, nose, small intestine, and colon), the vast majority of
bacteria live in the large intestine. Hands, for example, may look clean, but
in reality, there are many microorganisms that are present on the surface which
are invisible to the naked eye (one must zoom in at least 1000 times to see
them since the size of the largest microbes are equal to one thousandth of a
millimeter). Our hands and nails are the main targets of microbial
contamination because they are much more exposed than the rest of the body
parts. The hands have hundreds of microorganisms per cm2 originating from other
body parts and from the outside. Unfortunately, the hands become contaminated
very easily and, in turn, they contaminate everything they touch.
In addition to the skin, there is the possibility of contamination through mucous membranes. These are the membranes lining the cavities of the body which are kept constantly moist by mucus: mouth, nose, eyes, genitals, etc. Mouth is vulnerable to contamination because of the presence of food debris, temperature and humidity, thereby creating an excellent habitat for a wide variety of bacteria (streptococci, lactobacilli, corinebacteria, staphylococcus, etc.) which are potential causes of diseases, even severe, if these manage to reach the deeper tissues or the bloodstream after trauma or surgical wounds. In addition to being a potential cause of extra-oral disease, the microbial population of the oral cavity, along with some of its components, is the protagonist of diseases of the mouth, which attack the teeth, gums and supporting tissues. The root cause of all these diseases is the presence of bacteria in the same microbial population of the oral cavity. The main bacteria responsible for cavities are Streptococcus mutans (able to bind to the surface of enamel and to build a network to join many other organisms, forming the so-called plaque) and Lactobacillus (even though it is unable to bind directly to enamel, it is the main producer of acid, which develops tooth decay). Nasal membranes are a source of infection for all airborne microbes. The germs expelled through coughing, sneezing, or even just by talking can directly contaminate not only air but also objects and the hands of the person who sneezes or coughs. Hence, microbes on the hands are transferred to other people simply through a handshake or by touching everyday objects.
Conclusion
Primary
sources of contamination are your body and dust circulation in the lab. Therefore,
there are several steps need to follow to prevent or minimize contamination in
our experiments. Such as use good
aseptic techniques, reduce accidents, keep the laboratory clean, routinely
monitor for contamination, and sterilizing the apparatus that we
want to use.
Name: Ahmad Azizul Bin Md Sadik
Matric card no.: 114116
LAB 4 :
SOURCES OF CONTAMINATION AND INFECTION
Introduction
Airborne
microorganisms are usually carried on dust particles, although some may be
carried directly by air currents (for example,fungal spores). It is important
for microbiologists to be aware of the potential for contamination by airborne
microorganisms. Carefully observation of simple precaution reduces the risk of
contamination of the cultures.
Every human is colonized by billions of microorganisms.
These microorganisms, some of them are vital to our wellbeing, constitute our
resident or normal microflora. Resident microorganisms are nourished by the
chemicals and moisture excreted by the human body. In moist areas such as
armpit, there may be one million bacteria per cm^3; on the drier
skin of the forearm, there may be 10000 bacteria per cm.
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 are
largely consists of nonpathogen or opportunistic pathogens.
Large numbers of transients enter the upper respiratory
tract as we breathe or eat. They may also come from our own hands or 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
Material & Reagents :
- Molten nutrient agar
- Sterile water
- Sterile petri dishes
- Sterile clinical swab
- Pipette and tips
Results :
Hand :
Breath :
Cough :
Ear :
Air :
Discussion :
Bacterial contamination is a situation which occurs when bacteria end up in a location where they are not supposed to be. It is
often used to refer to contamination of food by bacteriawhich can cause disease, but bacterial contamination can also occur in other settings. This situation is not
desirable, because it can pose a health threat and cause other problems. As a
result, steps are taken to avoid bacterial contamination in settings where it can become an issue.
In scientific
research, bacterial contamination of specimens can be an issue, as cancontamination of specimens taken for analysis by a pathologist. The
presence of unwantedbacteria can foul an experiment, throw off pathology results, or
simply confuse a researcher.Bacteria spread readily through labs via a variety of surfaces,
including equipment which is not properly sterilized, dirty hands, and through
ventilation systems.
Prevention of
bacterial contamination can be challenging. Keeping spaces clean and observing proper
handling procedure is a big part of prevention. Simple steps like washing
hands, dipping shoes in an antibacterial bath after exiting a patient's room,
and wearing gloves to handle specimens can cut down a great deal on the risk of
passing bacteria from one place to another. It is also important to conduct
regular testing to check for bacterial contamination so that it can be identified before it makes someone sick or
causes problems with an experiment or test
.
Contamination
from air :
Air currents may bring the microorganisms from plant or animal
surfaces into air.These organisms may be either commensals or plant or animal
pathogens. Studies showthat plant pathogenic microorganisms are spread over
very long distances through air. Forexample, spores of Puccinia graminis travel
over a thousand kilometers. However, thetransmission of animal diseases is not
usually important in outside air.
The main source of airborne microorganisms is human beings.
Their surface floramay be shed at times and may be disseminated into the air.
Similarly, the commensal aswell as pathogenic flora of the upper respiratory
tract and the mouth are constantlydischarged into the air by activities like coughing,
sneezing, talking and laughing. Themicroorganisms are discharged out in
three different forms which are grouped on the basisof their relative size and
moisture content. They are droplets, droplet nuclei and infectiousdust. It was
Wells, who described the formation of droplet nuclei. This initiated the
studieson the significance of airborne transmission.
Contamination from ear :
Human medical literature supports the concern for potential
iatrogenic inoculation of bacteria into the ear canal. In one documented case,
a nurse developed otitis externa caused by a meticillin-resistant Staphylococcus. When the otitis recurred after
treatment, culture of the earpieces of her stethoscope revealed a similar
organism, indicating a possible fomite for recontamination and relapsing
infection.
Most ear cleaning solutions are designed for repeated use,
and may be used both during an active ear infection and in healthy ears. The
possibility of contamination of an ear cleaning solution or its container could
contribute to spread of a pathogenic organism from one ear to another, could
contribute to spread from one dog to another if the solution is shared, or could
contribute to recurrent or persistent infections. The aim of this study was to
investigate the prevalence of bacterial contamination of commercial ear
cleaners after routine home use and to describe the characteristics that are
associated with contamination.
Contamination from breath :
Even though we cannot see them with our naked eye,
microscopic organisms are living inside our nasal passageways. Although most of
these bacteria are non-pathogenic, some may induce illness if they successfully
break through the bodies defense systems. Some examples of these non-pathogenic
bacteria are Streptococcus, Neisseria, Haemophilus,
and Micrococcus.
Some of the pathogenic examples include Staphylococcus aureus, Corynebacterium
diphtheriae, Streptococcus
pneumoniae, and Haemophilus
influenzae among
others.
Staphylococcus
epidermidis with
Corynebacteria predominantly colonizes the upper respiratory tract, especially
the nostrils. S.
epidermidis covers
90%-100% staphylococci from the nasal cavity when S. aureus is not
present. When S.
aureus is
present, the amount of S.
epidermidis dramatically
decreases. It is also present on human skin and mucosa. It may form biofilms to
attach securely to the epithelial cells in the nasal passageway. The S.
epidermidis has
lysostaphin in the peptidoglycan that can prevent it from lysis. The peptidoglycan
is connected to the teichoic acids by covalent bonds. S.
epidermidis has
glycerol teichoic acid glucosyl residues which makes it differ from S. aureaus bacteria. S.
epidermidis can
use glucose anaerobically , but most strains make acetoin, phosphatase and
reduce nitrate. All strains can produce acid when exposed to sugar, except a
couple of sugars like mannitol, when oxygen is present.
Corynebacterium is a Gram-positive normal flora in the
nose. The Corynebacterial envelop is made up of peptidoglycan, arabinogalactan,
corynemycloic and corynemycolenic acids, trehalose dimycolates, and
phosphatides of mannose and inositol. The lipoidal antigens on the cell surface
makes it invasive to the host's immune system, but it doesn't allow the
bacteria to attach firmly to the surface of the nares. The Corynebacterial are
facultatively aerobic organisms. They ferment glucose for energy, but they are
unable to use maltose or galactose. They have granules of long-chain
polyphosphate that stores phosphate and will be used as energy in stressful
times. Most species of Corynebacterium will not cause diseases in humans;
however, there is a specific species that is highly infectious. The Corynebacterium
diphtheriae causes
infection in the upper respiratory tract, and can be deadly if untreated.
Contamination from hands :
Medical hand hygiene pertains
to the hygiene practices related to the administration of medicine and medical
care that prevents or minimizes disease and the spreading of disease. The main
medical purpose of washing hands is to cleanse the hands of pathogens (including bacteria or viruses) and chemicals which can cause personal harm
or disease. This is especially important for people who handle food or work in
the medical field, but it is also an important practice for the general public.
People can become infected with respiratory illnesses such as influenza or the
common cold, for example, if they don't wash their hands before touching their eyes,
nose, or mouth. Indeed, the Centers for Disease Control and Prevention (CDC) has stated: "It is well documented that one
of the most important measures for preventing the spread of pathogens is
effective hand washing." As a general rule, handwashing protects people
poorly or not at all from droplet- and airborne diseases, such as measles, chickenpox, influenza, and tuberrculosis.
It protects best against diseases transmittedthrough fecal-oral routes (such as many forms of stomach flu) and direct physical contact.
Contamination from coughing :
Whooping
cough (pertussis) is caused by the bacterium Bordetella pertussis. B. pertussis is a very small Gram-negative aerobic
coccobacillus that appears singly or in pairs. Its metabolism is respiratory,
never fermentative, and taxonomically, Bordetella is placed among the "Gram-negative Aerobic Rods
and Cocci" in Bergey's Manual. Bordetella is not assigned to any family. The bacteria are
nutritionally fastidious and are usually cultivated on rich media supplemented
with blood. They can be grown in synthetic medium, however, which contains
buffer, salts, an amino acid energy source, and growth factors such as
nicotinamide (for which there is a strict requirement). Even on blood agar the
organism grows slowly and requires 3-6 days to form pinpoint colonies.
Conclusions :
References :
- http://textbookofbacteriology.net/pertussis.html
- http://en.wikipedia.org/wiki/Hand_washing
- http://www.scribd.com/doc/50689659/Air-Microbiology
- http://microbewiki.kenyon.edu/index.php/Nasal_passageway
- http://www.sciencedirect.com/science/article/pii/S0304389409006281
- http://onlinelibrary.wiley.com/doi/10.1111/j.1365-3164.2011.00988.x/pdf
