Effect of mouse strain and age on detection of mouse parvovirus 1 by use of serologic testing and polymerase chain reaction analysis

Background and Purpose: Detection of mouse parvovirus 1 (MPV) depends on us e of serologic and polymerase chain reaction (PCR) assays. These assays wer e evaluated for their ability to detect virus specific antibodies or viral DNA in multiple strains and ages of mice inoculated with MPV. Methods: Twelve-week-old ICR, BALB/c, C3H, C57BL/6, and DBA/2 mice and four - and eight-week-old ICR mice were inoculated with MPV. Serum was harvested four weeks after inoculation and analyzed by use of recombinant non struct ural protein 1 (rNS1) enzyme-linked immunosorbent assay (ELISA), minute vir us of mice (MVM) ELISA, and MPV indirect fluorescent antibody (IFA), MVM IF A, and MPV hemagglutination inhibition (HAI) assays. Select tissues were ha rvested and analyzed by use of an MPV-specific PCR assay. Results: The number of mice in each group with detectable MPV-specific anti bodies or MPV DNA varied with mouse strain, mouse age when inoculated, and viral dose. Seroconversion in mice inoculated at 12 weeks of age was detect ed almost exclusively by use of the MPV IFA and MPV HAI assays, whereas ser oconversion in almost all mice inoculated at 4 and 8 weeks of age was detec ted by use of all immunoassays except the MVM ELISA, Viral DNA was detected by use of PCR analysis in all strains and ages of mice except DBA/2 mice. Conclusions: Mouse strain and age have important roles in seroconversion to nonstructural and structural MPV antigens and persistence of viral DNA in mouse tissues. Therefore, diagnostic serologic testing and PCR analysis sho uld be considered within the context of mouse strain and age at the time of MPV exposure, especially when sentinel mice are used for surveillance.