Dr. Smith’s research interests are infectious diseases of laboratory and wild rodents and appropriate housing modalities for laboratory-maintained rodents. She has worked extensively in developing diagnostic tests for viruses of rodents and has studied the immunomodulatory properties of several naturally occurring viral infections of laboratory rodents. She has shown that two of the most common viruses of laboratory mice, mouse hepatitis virus (MHV) and mouse parvovirus, can alter host immune responses. Both agents affect T cell function and MHV also compromises accessory (antigen-presenting) cell function. Dr. Smith has also surveyed wild rodent populations in Australia, Madagascar, rural Connecticut, the New Haven (CT) landfill, the Chicago Forest Preserve and University City in Philadelphia for the occurrence of viral and bacterial agents as well as parasites. Each population was unique in terms of microbial flora. In some cases human pathogens were detected and, in the case of the Philadelphia mice, almost all were Helicobacter-positive by polymerase chain reaction. This is the first report of Helicobacter, which is common in laboratory mice, in wild rodents.

The explosive increase in the number of genetically altered mice used in research has been accompanied by shortages of housing space. The Guide for the Care and Use of Laboratory Animals (the Guide; National Research Council, 1996) contains guidelines for the amount of cage space required by several laboratory-housed species, including mice. The guidelines are based on the weight of the animals and are not supported by experimental data but are used by accreditation bodies during facility inspections. Others have shown that mice housed with reduced amounts of floor space exhibit reduced aggression. Dr. Smith and collaborators have published results of housing density studies using four inbred strains of mice and cages with different amounts of floor space. They concluded that mice can be housed at twice the density (half the cage space) recommended in the Guide without substantial change in their micro-environment (in-cage carbon dioxide and ammonia levels, temperature and humidity).