Mobile phones, especially ones with internet capabilities, have recently
entered our lives and become essential parts of our daily lives. As a result, they have
become an important factor in the spread of pathogens, especially among teenagers.
The aim of this research is to compare smartphone case materials and the glass
back of the phone (Apple iPhone 4S®), based on their contamination by bacteria after
1 week of usage.
The research question of this investigation is: “How do the leather, silicone
and plastic smartphone cases and the glass back of the phone without any case
differ in terms of total bacteria count, measured using the viable cell counting method
after a timespan of one week with daily usage of exactly one charge cycle?”
The method used to investigate the research question is the viable cell
counting method. The case is first disinfected and used everyday until the phone
battery runs out. Culture is taken from the case by a cotton swab after 1 week and
then is serial diluted up to the factor of 105. All dilution factors are incubated in LB
agar plates for 24 hours at 37ºC. Bacterial colonies are counted, and the dilution
factor with colony count between 30-300 bacteria is used in data analysis.
The mean results of viable bacteria number per ml of culture (in CFU/ml) are
as follows: 8.86x105 for leather, 7.28x105 for silicone, 6.32x105 for plastic and
4.42x105 for glass. ANOVA tests proved that there is indeed significant difference
between test groups (p = 0.015114832). The conclusion is that all smartphones get
contaminated by bacteria, but the glass has the lowest bacteria count showing that
smartphone cases should be avoided for hygiene as much as possible. If a case is
absolutely necessary, leather ones should not be preferred
