[Investigation of microbial colonization of computer keyboards used inside and outside hospital environments]

Computers have been commonly used in daily life and at hospitals by medical staff. This study was carried out to search the microbial colonization of computer keyboards and mice used inside and outside hospital environments. Keyboards and mice samples from a total of 398 computers were included to the study, in which 38 were used by doctors and nurses in the hospital clinics (Group 1); 32 by the medical faculty students (Group 2), and 328 by university students (Group 3) in the computer laboratories of Selcuk University, Konya (located at middle Anatolia). Of the computers, 96.7% (n:385) have been found to be colonized by coagulase-negative staphylococci (CONS), 13.1% (n:52) by gram-positive spore-forming bacilli and 8.8% (n:35) by corynebacteria; followed by Candida spp. (4.2%), gram-negative bacilli (1.7%) [Acinetobacter spp. (n:4), Pseudomonas sp. (n:l), Klebsiella sp. (n:l), E. coli (n:1)], Staphylococcus aureus (1.5%), and molds (Penicillium, Aspergillus; 1.2%). The isolation rates of CoNS were similar between the groups (94,7%, 93.7%, and 97.2%, respectively). However it was noted that all of the gram-negative bacterial isolates (7/38; 18.4%) were from the samples collected from hospital computers (Group 1). Susceptibility rates of CoNS isolates to cefoxitin were detected as 26.2% in Group 1, 79.2% in Group 2, and 91.3% in Group 3. Five out of six S. aureus strains were found susceptible to cefoxitin, except one isolated from a sample of Group 1. Linezolid resistance in both CoNS and S. aureus isolates were not determined in any groups. As a result, according to the data obtained from this study as well as from the other foreign studies, the computer keyboards and mice which are widely used in the hospital settings, are being the source of potential cross contamination in the development of nosocomial infections. Therefore the computers should be cleaned properly frequently and hand washing procedures and disinfection rules should be obeyed after the use of computers before handling the patients.