Studies on the development of an ELISA kit for microbiological monitoring. 2. Improvement of the prototype ELISA kit with special references to mouse hepatitis virus antigen

Simultaneous serodetection of major rat infectious pathogens by a multiplex immunochromatographic assay

Rapid and simple serologic tests that require only a small amount of blood without the euthanization of animals are valuable for microbial control in colonies of laboratory animals. In this study, we developed a multiplex immunochromatographic assay (ICA) for detection of antibodies to Sendai virus (also known as hemagglutinating virus of Japan), hantavirus, and sialodacryoadenitis virus, which are causative agents of major infectious diseases in rats. For this assay, an ICA strip was placed into a microtube containing 150 µl PBS and either 0.75 µl of rat serum or 1.5 µl of whole blood. Binding antibodies were visualized by using anti-rat IgG antibody-conjugated colloidal gold. Under these conditions, the multiplex ICA simultaneously and specifically detected antibodies to multiple antigens. Positive serum samples for each infectious disease were used to evaluate the sensitivity and specificity of the multiplex ICA. The sensitivities of the multiplex ICA for Sendai virus, hantavirus, and sialodacryoadenitis virus were 100%, 100%, and 81%, respectively. No nonspecific reactions were observed in any of the 52 positive sera against heterologous antigens. In addition, 10 samples of uninfected sera did not show any bands except for the control line. These observations indicate high specificity of the multiplex ICA. Moreover, the multiplex ICA could be applied to diluted blood. These results indicate that the multiplex ICA is appropriate for rapid and simple serological testing of laboratory rats.

First trial in the developmental phase of the "performance evaluation program" based on the ICLAS animal quality network program: self-assessment of microbiological monitoring methods using test samples supplied by ICLAS

The first trial in the developmental phase of the "Performance Evaluation Program" based on the new programs of the International Council for Laboratory Animal Science (ICLAS) was carried out. ICLAS supplied test samples to each diagnostic laboratory for self-assessment of microbiological monitoring methods. We found that 1 mouse serum sample was positive for mouse minute virus and another was positive for Mycoplasma pulmonis antibodies, and 1 rat serum sample was positive for Sendai virus antibody. Mouse parvovirus was detected from mouse spleen and mesenteric lymph node homogenate, and Helicobacter spp. were detected from mouse feces. Corynebacterium bovis was isolated from a mouse skin sample. These results were in agreement with those notified by the ICLAS after the trial. After this trial, the program will eventually be made available to all diagnostic laboratories willing to participate in it.