Two enzyme immunoassays for the detection of antibody to rodent coronaviruses

Abstract

Two enzyme immunoassays for detection of antibody to rodent coronaviruses were compared. Mouse hepatitis virus (MHV), strain JHM, antigen was in the form of formalin-fixed, infected 17 C1 1 cells. This antigen detected antibody to the homologous strain of MHV as well as to two heterologous MHV strains and a serologically related rat coronavirus, sialodacryodenititis virus. Antibody titers in assays using horseradish peroxidase (HRP)-conjugated or ureiase-conjugated anti-mouse IgG were substantially higher than in an indirect immunofluorescence assay. The ureiase assay was somewhat more sensitive than the HRP assay. MHV-JHM antigen was stable under a variety of storage conditions for at least two months.

Microbiological Assessment of Laboratory Rats and Mice

“…Such a response is typical of disease-resistant inbred strains (Brownstein and others 1981) and outbred stocks (Parker and others 1978), although in 1 study, the Sendai virus seroconversion rate for outbred sentinel mice was lower than that for inbred strains (Artwhol and others 1994). Detectable levels of serum antibodies take on average 2 to 3 weeks to develop (Parker and Reynolds 1968;Peters and Collins 1983;Smith 1983). It is therefore recommended that sentinels be kept in a colony for at least 1 month and that sick animals be allowed to convalesce for several weeks before they are tested.…”

Susceptibility of rodent cell lines to rat coronaviruses and differential enhancement by trypsin or DEAE-dextran

“…The percentage of the monolayer that consisted of syncytia was estimated, and all infected and mock-inoculated cultures were harvested at 72 h post-inoculation. Air-dried, fixed cells were incubated with SDAV-immune mouse ascitic fluid or with pooled SDAV-immune serum from experimentally infected rats followed by incubation with fluoresceinated goat anti-species immunoglobulin (Antibodies, Inc., Davis, CA) containing 0.01% Evans's blue [14]. Cells were examined at a magnification of x 200 with a transmitted light fluorescence microscope.…”

Modulation of lethal and persistent rat parvovirus infection by antibody

“…Athymic male rats were bred to euthymic heterozygous female rats to produce mixed litters of athymic and euthymic pups for virus inoculation. Randomly selected rats from each group were tested for antibodies to common murine viruses and Mycoplasma pulmonis by immunofluorescence assay (IFA) [12]. Rats tested prior to inoculation with RV, sham-inoculated dams and uninoculated control rats were seronegative.…”