Animal Health

Investigation of Bacterial Load in Multi-Species Laboratory Workspaces

  • Lori Layman (Iowa State University)
  • Locke Karriker (Iowa State University)
  • Erin Bradley (Iowa State University)


Multi-purpose/multi-species laboratories in veterinary clinics may have an increased risk for bacterial contamination due to the possibility for high traffic and diverse exposures from different farms and species. The goal of this trial was to investigate the level of possible contamination in the shared areas and to evaluate the efficacy of the current SOPs (standard operating procedures) in minimizing microbial contamination of laboratory areas. Specific objectives were to: (1) identify which areas of the laboratory and shared resources have the highest level of contamination and (2) determine whether the current cleaning and decontamination methods are effective and in use.

Two trials, totaling 115 samples, were conducted over a two week period using Replicate Organism Detection and Counting (RODAC) surface contact agar plates. The first trial consisted of randomized sampling within the field laboratory, field equipment shared between species and veterinary service vehicles. The second trial further sampled identified problem areas before and/or after cleaning/disinfection procedures. The experimenter was blinded to the status of the surfaces tested. Commercially available disinfectants typically found in homes, farms, and/or clinic laboratories were used at recommended rates and contact times during testing.

Samples collected were incubated for 24 hours at 37°C with 5% CO2. Following identification processes, the most common species of bacteria isolated were Staphylococcus sp. These were most frequently isolated in the service vehicles.

Hard surfaces in the vehicle were able to be cleaned and disinfected sufficiently, but the carpeted areas retained contamination even after cleaning.

The findings of this project suggest that fomite transfer of bacterial organisms through the use of a multi-purpose service vehicle could potentially spread undesirable pathogens from farm to farm unknowingly. Increased adherence to strict biosecurity standards at the farm level can help to prevent this transfer.

Keywords: ASL R2252

How to Cite:

Layman, L., Karriker, L. & Bradley, E., (2008) “Investigation of Bacterial Load in Multi-Species Laboratory Workspaces”, Iowa State University Animal Industry Report 5(1). doi:

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Published on
01 Jan 2008
Peer Reviewed