Folia Microbiologica

, Volume 60, Issue 2, pp 159–164 | Cite as

Bacteria on smartphone touchscreens in a German university setting and evaluation of two popular cleaning methods using commercially available cleaning products

  • Markus EgertEmail author
  • Kerstin Späth
  • Karoline Weik
  • Heike Kunzelmann
  • Christian Horn
  • Matthias Kohl
  • Frithjof Blessing


Smartphone touchscreens are known as pathogen carriers in clinical environments. However, despite a rapidly growing number of smartphone users worldwide, little is known about bacterial contamination of smartphone touchscreens in non-clinical settings. Such data are needed to better understand the hygienic relevance of these increasingly popular items. Here, 60 touchscreens of smartphones provided by randomly chosen students of a German university were sampled by directly touching them with contact agar plates. The average bacterial load of uncleaned touchscreens was 1.37 ± 0.33 CFU/cm2. Touchscreens wiped with commercially available microfiber cloths or alcohol-impregnated lens wipes contained significantly less bacteria than uncleaned touchscreens, i.e., 0.22 ± 0.10 CFU/cm2 and 0.06 ± 0.02 CFU/cm2, respectively. Bacteria isolated from cleaned and uncleaned touchscreens were identified by means of MALDI Biotyping. Out of 111 bacterial isolates, 56 isolates (50 %) were identified to genus level and 27 (24 %) to species level. The vast majority of the identified bacteria were typical human skin, mouth, lung, and intestinal commensals, mostly affiliated with the genera Staphylococcus and Micrococcus. Five out of 10 identified species were opportunistic pathogens. In conclusion, the touchscreens investigated here showed low bacterial loads and a species spectrum that is typical for frequently touched surfaces in domestic and public environments, the general health risk of which is still under debate.


Healthcare Worker Bacterial Load Colony Count Cleaning Method Heterotrophic Plate Count 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



The authors wish to thank all students who participated in the study and provided their smartphones for microbiological analyses as well as Dr. Wayne Young (AgResearch, Palmerston North, NZ) for English suggestions.

Conflict of interest



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Copyright information

© Institute of Microbiology, Academy of Sciences of the Czech Republic, v.v.i. 2014

Authors and Affiliations

  • Markus Egert
    • 1
    Email author
  • Kerstin Späth
    • 1
  • Karoline Weik
    • 1
  • Heike Kunzelmann
    • 1
  • Christian Horn
    • 2
  • Matthias Kohl
    • 3
  • Frithjof Blessing
    • 1
    • 2
  1. 1.Faculty of Medical and Life Sciences, Microbiology and Hygiene GroupFurtwangen UniversityVillingen-SchwenningenGermany
  2. 2.Institute for Laboratory MedicineSingenGermany
  3. 3.Faculty of Medical and Life Sciences, Group for Statistics in Biology and MedicineFurtwangen UniversityVillingen-SchwenningenGermany

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