Evaluation of isolator caging systems for protection of mice against challenge with mouse hepatitis virus

Abstract

Two isolator caging systems were evaluated against challenge with MHV-Y, an enterotropic strain of mouse hepatitis virus. The systems were similar in that they both used an identical shoebox cage equipped with a polycarbonate filter top incorporating a Reemay filter. They differed in that one system supplied HEPA-filtered air through a grommet in the filter lid so that the cage was pressurized slightly. A rack holding 60 cages (30 front and back) was utilized. Thirty cages without filter tops housed one mouse each that had been infected orally with 19,000 ID50 of MHV-Y and an uninfected cagemate. The remaining 30 cages, each housing 2 uninfected mice were divided into 3 groups of 10 cages. Group I cages (controls) had no filter top; Group II cages were equipped with filter tops; and Group III were equipped with filter tops and intracage HEPA-filtered air. The cages housing uninfected mice were interspersed between, above, below and behind cages housing infected mice. The uninfected mice were maintained in contact with the MHV-Y infected mice for 8 weeks. Transmission of MHV-Y was determined serologically by indirect ELISA. All mice housed within the Group I cages (control) seroconverted to MHV, while only 4 mice (2 cages) seroconverted in Group II, and no mice seroconverted in Group III.

Microbiological monitoring of laboratory mice and biocontainment in individually ventilated cages: a field study

“…Over recent years, the use of individually ventilated cage (IVC) rack systems in laboratory rodent facilities has increased. In a typical IVC rack, each cage receives high efficiency particle absorbance (HEPA)-filtered air which, when supplied under positive pressure, protects the animals in the cages from airborne infectious or other noxious particulate agents present in the environment (Cunliffe-Beamer & Les 1983, Lipman et al 1993, Clough et al 1995, Lipman 1999. Similarly, the exhaust air from the cages is normally also HEPAfiltered before it is returned into the room environment.…”

New Building, Old Parasite: Mesostigmatid Mites--An Ever-Present Threat to Barrier Rodent Facilities

“…Pathogen-free rodents are readily available from vendors, and widespread use of barrier caging systems in concert with sterilized equipment, high-efficiency particulate air (HEPA)-filtered air cabinets, protective clothing, and disinfection help keep pathogens out (Brielmeier et al 2006;Dillehay et al 1990;Lipman et al 1993;NRC 1991;Otto and Tolwani 2002;Stakutis 2003). Regular health surveillance (Livingston 2003) helps to detect excluded organisms, and should there be an outbreak, mites and pinworms are variously susceptible to treatment with parasiticides such as avermectins, pyrethroids, and benzimidazoles (Baumans et al 1988;Bean-Knudsen et al 1986;Bornstein et al 2006;Coghlan et al 1993;Flynn et al 1989;Hill et al 2005Hill et al , 2006Huerkamp et al 2000Huerkamp et al , 2004Huerkamp et al , 2005Klement et al 1996;Pullium et al 2005;Santora et al 2002;Sueta et al 2002).…”

Evaluation of a Forced-air-ventilated Micro-isolation System for Protection of Mice against Pasteurella pneumotropica.

“…Although previous studies have shown that the physical environment inside cages can be controlled adequately by setting the intra-cage ventilation at 60 ACH when FVMIS is used [6,10,13,26], the capability of FVMIS to prevent inter-cage transmission of [15]. In those studies, however, serial follow-up of the state of microbial transmission in the same animals was not carried out.…”

“…Dillehay et al reported that MIS were effective for prevention of inter-cage transmission of mouse hepatitis virus (MHV) [5], while Lipman et al performed challenge tests using MHV to examine the preventive capability of a ventilated caging system (Micro-FLO/ KUP 60 cage with Bio-Pak; Allentown Caging Equipment Co., Allentown, NJ) [15]. They concluded that these systems were protective against MHV.…”