DWHC Wildlife: Bacteriological?

Abstract

There is a growing concern in the Dutch Wildlife Health Centre (DWHC) regarding the current storage method of their bacterial strains on stab cultures and the great number of mixed cultures in their bacterial results. The bacteriology of DWHC is performed by collaboration between DWHC and the Veterinary Medical Diagnostic Centre (VMDC). DWHC initiated the inoculation of bacterial strains and VMDC performs the subsequent steps and ultimately stores these strains. This study has a main focus on the evaluation of this growing concern by evaluating the current bacterial database. The study first evaluates the present bacteria in the stored stab culture set of 2012 by repeating the cultivation of these bacteria. And secondly, it compares the initial identification method of DWHC and VMDC with the working method derived from the literature to analyze which factors could play a part in obtaining ‘mixed culture’ as a bacterial outcome. Furthermore, the evaluation of the DWHC administration and interviews with pathobiology staff members is added to the initial study outline. The evaluation of the DWHC database is done by crosschecking the extended data by DWHC. After analyzing the results we are able to conclude that the facultative anaerobes or obligate anaerobes are not able to survive in the long term on stab cultures. And second, that the mixed cultures from the stab culture set of 2012 are most likely contamination by ubiquitous bacteria. This leads to a list of recommendations including (1) adding a differential diagnosis to the application for bacterial testing to determine which selective plates are indicated to use when contamination risk is high and (2) freezing the bacteria at a minimum of -70°C as the best storage method.