Microbial Contamination of Touch Screen Devices

This study aims to detect and analyse the microbial load that is present on the surface area of the screen of these phone devices and also identify the type of the microorganisms present. Additionally the paper will try to differential and contrast between the microbial load that is present on the touch screen and the keypad phone device.

Running head: BIOSCIENCE
BIOSCIENCE
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Project title
Microbial Contamination of the Touch Screen Devices
Null hypothesis
The null hypothesis states that there will be no microbes present on the touch screen
of the mobile phone devices and also on the keyboard of the devices.
Aims and objectives
The occurrence of the bacterial pathogens on the surface of the touch screen mobile
devices needs to be determined.
The types as well as the number of the microorganisms that is present on the surface
of the touch screen phone devices needs to be determined.
Analysis and comparison of the two devices which contains more number of microbes
on the surface area like the keypad device or the touch screen device.
Introduction
Mobile phones have become an essential material goods in the recent times. With the
advancement of the technology, there are more modern smartphones available which makes it
possible for the transfer of any form of language along with the functions like receiving of
messages, emails, chat, surf the web and other such functions. These smartphones available
nowadays are managed through the presence of a glass touchscreen which can be contacted
through finger touch. This makes the touchscreen significantly prone to becoming carriers of
the microorganisms that are present on the hand. While conducting the following research, it
was observed that during the use of the selected devices, not only the fingers, but also the
face, the ear, the mouth and other parts were coming in contact with the screen of the phone.

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In the research that was conducted, it was observed that when the keypad device is
considered, it shows similar microbial load. Additionally the mechanical waves along with
the electromagnetic radiations which are given out by the smartphones attracts the presence
of the microorganisms. From the research conducted, it could also be implied that the number
of the microbes present on the surface also depended on the personal hygiene of the user and
also on the environment and the occupational ambience of the user. This could due to the fact
that since the selected device was being used in a clinical environment which is highly
susceptible to harbour large concentrations of microbial populations, this device could have
become an agent of bacterial transmission. The research performed also revealed that
smartphones are also responsible for emission of electromagnetic waves, therefore it also
became important to assess the mechanism with which electromagnetic waves affected the
microbial population that was present on the surface area of the touch screen devices as well
as the keypad phone devices. When the keypad devices were considered in this research, it
was postulated that the keys which were exposed to various microbial population might also
be responsible for cross-contamination especially in case of hospital-acquired infections.
Therefore in order to reduce these, it was important to regularly clean the device and
undertake adequate disinfection practices, in the following research.
This study aims to detect and analyse the microbial load that is present on the surface
area of the screen of these phone devices and also identify the type of the microorganisms
present. Additionally the paper will try to differential and contrast between the microbial load
that is present on the touch screen and the keypad phone device.
Key outcomes/journals/authors
The key outcomes expected from this study is that this research will help to compare
the microbes that are present to the different devices, which will be followed by using wipes

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to check the number of microbes present after each wash. It can also be expected that the
microorganisms growing on the plates
Progress to date
Methods
Sampling
The first step was collection of touch screen devices and keypad phone devices for
determination of the microbial load. A surface area of 25 cm2 was taken into consideration
and was marked using a handmade filter frame of sterilized UV paper rays, which was then
placed on the touch screen for the purpose of microbial recovery. For the collection of the
microbes, a sterile dry cotton swab was rubbed over the marked surface thoroughly for about
10 times. This was then immersed into a saline solution of 0.9% NaCl which was sterilised
and further this was vortexed for about 2 minutes.
The method of swabbing was used since this method since this acts as a standard
laboratory technique for the determination of the recovery and the counts of the microbial
population. This helps to enhance the true identification of the microorganisms.
The swab collected was then spread on the plate containing nutrient agar. This was
then incubated at 37 °C aerobically for 48 h. This saline solution was then centrifuged at a
10,000 rpm for 5 min. After this the pellet was suspended again in a saline solution of 100 μl
and poured in the plates. A pour plate technique was used for this. This method is convenient
for the method as pour plate technique will allow the microorganism to grow on the surface
of the agar on the plate as well as in the agar. The spread plate technique is not used since this
will only allow the microbes to grow on the surface.
Preparation of agar

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The nutrient agar was prepared along with peptone water in an aseptic condition. Here
nutrient agar was chosen as the culture medium since this acts a universal medium for most
of the cultivable microorganisms. This contains complex nutritional components so that
different types of bacteria and fungi can grow on the agar plate.
Serial dilution
For sub-culturing the obtained cultures, the culture solution was serially diluted up to
a dilution factor of 10-7. Then from this, the dilutions of 10-5, 10-6 were plated. This was
because dilutions lower than this would give a lawn of culture and dilutions more than this
would give very less colonies.
Streak plate
In order to prepare the steak plate, the colonies were poured and were spread on the plate
which was prepared beforehand. In order to study, identify and test the microbes, it is
required to collect the details from the different populations available. After the pour, a streak
plate was done and after this the spread plate was collected. From these plate the results were
collected and then calculations were done for the selected plates. The chosen plate was pour
plated with the dilution factor of 10-2 having three different colonies that needs to be sub-
cultured. Therefor these plates were incubated for 24 hours after streaking at a temperature of
37◦c.
Sub-culturing
By transferring the culture from the previous culture plate the sub-culturing was done to a
new agar plate. This was incubated for about 24 hours at 37oC. In order to extend the life of
the number of cells that is present in the culture, sub-culturing is conducted. Most of the time
the dilution of 10-2 is used for sub-culturing.

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Identification of the culture
For the identification of the microbial population, the gram staining technique was
used which differentiates between gram negative and gram positive bacteria. This was then
observed under the microscope under the 10X lens. This helped to identify the colony
morphology, the growth characteristics. For the identification process the biochemical profile
was also characterised which included the catalase, oxidase, coagulase, citrate and indole test.
Next step
While working in the laboratory, the safety practises should be implemented which
should be advised at the beginning of the work itself, however there are often certain
practices that lead to the mistakes done during the experiment. These might be:
While preparing the nutrient agar, the duration might be long enough which makes the
agar spill over while in the microwave oven.
When the touch screen phone was used this experiment was repeated several times
since the culture was hot, which gave negative results.
During the sub-culturing, necessary steps were taken in order to avoid contamination
since every time the culture is transferred there is a chance of cross-contamination to occur
(Rana et al. 2013).

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References
Chairman, K. and JA, R.S.A., 2017. Beware of pathogenic microbes in public utility
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Infection, 87(2), pp.77-83.
Koroglu, M., Gunal, S., Yildiz, F., Savas, M., Ozer, A. and Altindis, M., 2015. Comparison
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Mark, D., Leonard, C., Breen, H., Graydon, R., O'Gorman, C. and Kirk, S., 2014. Mobile
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