Isolation, Counting and Identification of Microorganisms from Elevator Button, ATM, and Smartphone Surface

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Objectives The purpose of this study was to identify and isolate bacteria on the surface of elevator buttons, ATM screens, and smartphone surfaces. Through this process, bacterial diversity and presence of pathogens on the surface were evaluated for the prospective public health and environment. Methods Bacterial samples collected from elevator buttons, ATM screen surfaces, and smartphone surfaces were analyzed their CFUs using LB agar plates. Unique colonies in the plates were isolated and identified by the 16S rRNA analysis. The diversity of the bacteria in the collected samples containing high number of CFU was monitored using the Denaturing Gradient Gel Electrophoresis (DGGE). Results and Discussion Among the instrument surfaces, the elevator buttons showed the highest CFU (average: 163±17 CFU/cm2). The samples from smartphone and ATM surfaces have 66±13 and 6±1 CFU, respectively. The CFU analysis also showed that the all collected samples had active bacterial species, and the 16S rRNA analysis indicated that pathogenic bacteria were existed on the surface on the buttons and screens. The DGGE analysis showed that higher diversity of bacterial species were found compare to the CFU analysis of the samples. This difference in the bacterial diversity is probably due to the difference in optimal cultivation conditions of each bacterial species in the samples. Conclusions The user interfaces of the elevators, ATMs, and smartphones contained high diversity of normal and pathogenic bacterial species. Thus attention must be paid to the transfer of pathogenic bacteria in children, pregnant women, immunocompromised patients.