Contaminated Shipping Materials Identified as the Source of Rotaviral Infection of Exported Mice

Abstract

Over a 4-wk period in 2017, we received notification from 7 different institutions that mice exported from our SPF barrier facilities had tested positive for mouse rotavirus (MRV). The exports originated from several different buildings across multiple campuses. Our institution excludes MRV in all of our barrier facilities and has historically been free of this virus. Extensive testing of our rooms from which the exported mice originated did not detect the presence of rotavirus. The single commonality among the 7 shipments was the use of shipping boxes acquired from one vendor. These shipping boxes arrived at our institution prepackaged with unsterilized feed and bedding, which we hypothesized was the source of the rotavirus. To test this hypothesis, we housed naïve sentinel mice in clean cages with feed and bedding transferred from 29 unopened, unused shipping boxes. Sentinel mice were exposed to this bedding and feed for 14 d and then evaluated through MRV serology and PCR assay. Of the 29 sentinels, 24 were seropositive for MRV, and 14 of the 29 were PCR positive. These results provided direct evidence that MRV detected by recipient institutions originated from the contaminated feed or bedding within the shipping boxes. To our knowledge, this report is the first description of contaminated materials in shipping boxes resulting in rotaviral infection of mice during export.

Health Monitoring of Laboratory Rodent Colonies—Talking about (R)evolution

“…Those substantial age-dependent differences regarding virus susceptibility are major advantages in terms of sanitation procedures, as virus eradication may be relatively simply achieved by a prolonged breeding cessation and strict hygienic measurements, as it was successfully conducted after an EDIM outbreak within an experimental barrier housing mice [ 56 ]. Due to sanitation procedures and strict hygienic measures, the actual prevalence of mouse and rat Rotaviruses is nowadays low; however, outbreaks occasionally occur, as was recently reported after exposure of exported mice to contaminated shipping boxes [ 57 ].…”

Rotavirus Samples processing using Indigenously Developed Molecular Transport Medium (IMTM)

“…Fomite transmission of rotavirus in general and during sample transportation in special lead to utilize the IMTM for rotavirus samples and its efficacy for providing good quality viral 20,21,22 genomic RNA for Real-time PCR. Rotavirus suspected stool samples were selected and parallel spiked in a commercially available medium (CMTM) and indigenously prepared medium (IMTM) for efficacy check and for comparative analysis through Real-time PCR.…”