Role of Housing Modalities on Management and Surveillance Strategies for Adventitious Agents of Rodents

Abstract

Specific pathogen-free (SPF) rodents for modern biomedical research need to be free of pathogens and other infectious agents that may not produce disease but nevertheless cause research interference. To meet this need, rodents have been rederived to eliminate adventitious agents and then housed in room- to cage-level barrier systems to exclude microbial contaminants. Because barriers can and do fail, routine health monitoring (HM) is necessary to verify the SPF status of colonies. Testing without strict adherence to biosecurity practices, however, can lead to the inadvertent transfer of unrecognized, inapparent agents among institutions and colonies. Microisolation caging systems have become popular for housing SPF rodents because they are versatile and provide a highly effective cage-level barrier to the entry and spread of adventitious agents. But when a microisolation-caged colony is contaminated, the cage-level barrier impedes the spread of infection and so the prevalence of infection is often low, which increases the chance of missing a contamination and complicates the corroboration of unexpected positive findings. The expanding production of genetically engineered mutant (GEM) rodent strains at research institutions, where biosecurity practices vary and the risk of microbial contamination can be high, underscores the importance of accurate HM results in mitigating the risk of the introduction and spread of microbial contaminants with the exchange of mutant rodent strains among investigators and institutions.

Of Mice, Dirty Mice, and Men: Using Mice To Understand Human Immunology

“…Animals were often housed in wooden cages that were difficult to clean and there were not effective means to identify pathogens (28). Starting in the mid 1900's there has been an increasing focus on identifying strategies to control the spread of pathogens in laboratory animal facilities.…”

Lurking in the Shadows: Emerging Rodent Infectious Diseases

“…Eradication involves standard approaches (e.g., depopulation, rederivation, neonatal transfer, antimicrobial therapy, stop breeding, test and cull) covered in detail elsewhere in this issue (Clifford and Watson 2008;Shek 2008). However, successful eradication is frequently where previously unrecognized (emerging) agents pose the most difficulty as they have somehow managed to survive in laboratory rodent colonies for decades without detection despite continual efforts to eliminate other infectious agents.…”

The challenges of implementing pathogen control strategies for fishes used in biomedical research

“…Such approaches require specialized and dedicated infrastructure and housing for animals, intensive screening of animals, routine monitoring of health status, implementation of strict quarantine methods — in addition to dedicated and specifically trained personnel to manage the operation (Yanabe et al, 2001; Watanabe et al, 2005; Morton et al, 2008; Ramsay et al, 2009a; Wolf et al, 2010). Relatively basic components of an animal health program, such as health monitoring, still require dedicated equipment, routine monitoring of animals, and regular oversight (Barthold, 1998; White et al, 1998; Nicklas et al, 2002; Gourdon, 2004; Shek, 2008). Indeed, even the most basic element of pathogen control – the maintenance of a stable, favorable, and well-defined environment (both macro- and micro-) in a facility – requires full-time, dedicated personnel with demonstrated expertise in the biology and husbandry of the animals in question.…”