Investigation of Staphylococcus spp. and Escherichia coli colonization and biofilm formation on university students’ mobile phones and hands

Mobile phones, which became indispensable in our daily lives, are likely to be colonized by microorganisms found in the hands of people using them. In this study, a total of 30 mobile phones and owner hands (30) were screened for Staphylococci and E. coli contamination in various departments at Mustafa Kemal University. For this purpose, samples were taken from the mobile phones and index fingers and thumbs of dominant hands of randomly selected 30 students studying at various departments at Mustafa Kemal University, Faculty of Arts and Sciences. Staphylococcus and Escherichia coli colonization were screened in these samples, and their susceptibility to 11 antimicrobials in different groups. And, oxacillin salt agar screening test was performed to detect methicillin resistance. Microplate (MP) method, Congo Red Agar (CRA) method and Standard Tube (ST) method were used to determine biofilm formation. A questionnaire about mobile phone usage habits was also applied to statistically investigate whether the colonization depends on the usage. According to our results, E. coli colonization was no found in any sample, while 31 samples were isolated as Coagulase-Negative Staphylococci (CoNS) and 2 samples as Staphylococcus aureus . Out of 30 samples collected from the mobile phones of the students, 53.3% was found as CoNS and 3.3% as S taphylococcus aureus . Whereas, among 30 samples collected from the hands of the students, CoNS was isolated in 50% and Staphylococcus aureus 3.3% of the samples. All 33 Staphylococci isolates were found to be susceptible to vancomycin and rifampicin, while 27% were found to be resistant to oxacilline , 36% to cefoxitin , 70% to ampicillin, 48% to tetracycline, 76% to erythromycin, 70% to penicillin, 30% to gentamicin, 30% to ampicillin- clavulanicase , 24% to ciprofloxacin, 27% to ciprofloxacin, 27% to trimethoprim/sulfamethoxazole and 27% to methicillin. It was determined that 9 (27.2 %) of the 33 Staphlococci isolates was resistant to methicillin. Staphylococci were 100% biofilm producers according to the microplate method. Especially hand hygiene should be carefully provided and mobile phones should be regularly cleaned in order to prevent bacterial colonization of mobile phones, and prevention strategies should be developed in terms of public health.