Germs Abound on Office Phones, Chairs, Desks (CME/CE)
; Associate Clinical Professor of Medicine, University of California, San Francisco and Dorothy Caputo, MA, BSN, RN, Nurse Planner discovered hundreds of unique microbial lineages (OTUs) at just two different office buildings ( BMC Microbiol online, April 8, 2008).
For the current study, the authors combined culture-based cell counting and multiplexed pyrosequencing of environmental ribosomal RNA gene sequences.
They swabbed about 13 cm 2 of the same surfaces in every building: chairs, phones, computer mice, computer keyboards, and desktops.
They found that human oral and nasal cavities as well as skin were the primary sources of office bacterial contamination.
Proteobacteria (Salmonella, Helicobacter) was the most common, followed by Firmicutes, Actinobacteria, and Bacteroidetes.
Bacteroidetes is associated with the human digestive tract and the genera does include pathogens, but the sequence information that the authors collected could not distinguish bacterial strains or species.
As for the differences in contamination levels based on gender, Kelley's group offered two possible explanations: Men are perceived as being less hygienic than women (washing their hands less frequently) and they also may shed more bacteria into the environment simply because they are generally larger than women.
Other bacterial genera noted in the study were associated with soils and with some environmental sources such as microbacteriaceae.
Finally, the samples from Tucson were quite different than those from New York and San Francisco, probably because of the desert soils.
For instance, bacteroidetes and Cyanobacteria were essentially absent in the Tucson samples but were seen in samples in the other cities.
The 549 bacterial genera found in this study was much higher than the 283 unique OTUs discovered in the Finnish study, the authors said, most likely because of broader sampling and deeper sequencing.