Lymphocytic Choriomeningitis Infection Undetected by Dirty-bedding Sentinel Monitoring and Revealed after Embryo Transfer of an Inbred Strain Derived from Wild Mice

• Published in: Comparative medicine Vol. 57; no. 3; pp. 272 - 281
• Main Authors: Ike, F, Bourgade, F, Ohsawa, K, Sato, H, Morikawa, S, Saijo, M, Kurane, I, Takimoto, K, Yamada, Y.K, Jaubert, J
• Format: Journal Article
• Language: English
• Published: United States American Association for Laboratory Animal Science 01.06.2007
• Subjects: Animal Husbandry; animal models; Animals; Animals, Wild; Animals, Wild - blood; Animals, Wild - virology; antibody detection; Cercopithecus aethiops; cesarean rederivation; Chlorocebus aethiops; disease detection; disease surveillance; Embryo Transfer; Embryo Transfer - veterinary; enzootic infection; Housing, Animal; inbred lines; laboratory animals; Life Sciences; litter (bedding); Lymphocytic Choriomeningitis; Lymphocytic Choriomeningitis - diagnosis; Lymphocytic Choriomeningitis - immunology; Lymphocytic Choriomeningitis - veterinary; Lymphocytic Choriomeningitis - virology; Lymphocytic choriomeningitis virus; Lymphocytic choriomeningitis virus - immunology; Lymphocytic choriomeningitis virus - isolation & purification; Mice; Mice, Inbred Strains; Rodent Diseases; Rodent Diseases - diagnosis; Rodent Diseases - virology; sentinel animals; Sentinel Surveillance; Sentinel Surveillance - veterinary; Serologic Tests; Serologic Tests - veterinary; Vero Cells; Vero Cells - virology; viral diseases of animals and humans; virus transmission
• ISSN: 1532-0820; 2769-819X

Persistent LCMV infection in wild-derived MAI/Pas mice housed under conventional conditions remained undetected for a decade, despite periodic health monitoring using dirty-bedding sentinels. When MAI/Pas mice were rederived by embryo transfer, recipient mothers produced antiLCMV antibodies, which first revealed the presence of the virus in the colony. Before this information was obtained, MAI/Pas mice had been shipped to another facility, undergone cesarean rederivation there, and been introduced into the recipient barrier. The foster mothers of rederived pups were LCMV-negative according to enzyme-linked immunosorbent assay, but sera of both cesarean-rederived MAI/Pas mice and their foster mothers were positive for LCMV infection by immunofluorescent assay (IFA). LCMV was isolated from the MAI/Pas mice, and its genomic RNA was sequenced. Examination of animal technicians in contact with LCMV-infected mice and of other mouse samples by IFA or a reverse transcriptase-polymerase chain reaction test (or both) revealed that neither the workers nor other animals had been infected with LCMV. Experimental data showed that LCMV transmission from persistently infected mice to naive ones occurred only after direct contact of animals housed in the same cage. This experience demonstrates the importance of careful viral monitoring in the transfer of laboratory rodents between institutions, the limitation of dirty-bedding sentinels for detection of LCMV infection, and the inadequacy of cesarean rederivation for elimination of enzootic LCMV infection.