Effectiveness of sentinel rodents for surveillance of exposure to undocumented bacterial pathogens in animal research facility

Abstract

The use of sentinel animals in animal research facilities is the cornerstone of animal health monitoring for
exposure to natural pathogens of laboratory animals. This is because infection with these pathogens produces no overt
signs of disease yet the infection may affect the outcome of research utilising these animals. One of the important
pathogens includes Klebsiella pneumoniae, whose prevalence can be high in laboratory animals. This study sought to
document the prevalence of K. pneumoniae and other undocumented bacterial pathogens in laboratory rodents for a 3-
year period. K. pneumoniae and Chryseobacterium gleum were isolated from sentinel ICR mice housed in three different
satellite animal laboratories, suggesting the effectiveness of the sentinel program. A novel strain of K. pneumoniae
ST3125 was recovered from the gastrointestinal tract of the ICR mouse. β-lactamase and virulence genes were detected
among K. pneumoniae and C. gleum strains, suggesting the acquisition of these genes from the users of the animal
research facilities. Examination of the animal housing environment, feed and water specimens however, returned
negative for the presence of K. pneumoniae and C. gleum suggesting that current hygiene practices were adequate in
controlling transmission from the environment. Nevertheless, stringent hygiene practices and infection control
protocols have to be applied in animal facilities to prevent the colonization and spread of pathogens capable of
distorting experimental results.