Isolation and Characterization of a Neurotropic Agent (MHG Virus) From Adult Rats

A spontaneous outbreak of Theiler's encephalomyelitis in a colony of severe combined immunodeficient mice in the UK

“…The virus recovered from this outbreak, however, was undistinguishable from a TMEV strain that had been used and passaged in the same laboratory for several months. There is also one report of natural infection with TMEV in adult rats (McConnel et at., 1964).The disease spreads gradually in an infected colony by faecal-oral transmission (Theiler & Gard, 1940). The virus is present as an asymptomatic enteric infection prevalent in young adult mice (National Research Council, 1991).…”

In vivo tropisms and kinetics of rat theilovirus infection in immunocompetent and immunodeficient rats

“…However, intracranial inoculation of RTV has been reported to cause CNS disease (McConnell et al, 1964; Rodrigues et al, 2005). In our studies intracranial inoculation of RTV1 did not cause clinical neurologic disease in Lewis rats nor was virus detected in the brain or spinal cord 10 weeks PI.…”

“…The first report of a TMEV-like pathogen infecting rats occurred in 1964 when a small group of Sprague Dawley (SD) rats were identified with central nervous system deficits and histopathologic lesions that resembled those of mice infected with TMEV (McConnell et al, 1964). The original isolate, known as MHG, was reported to cause paralysis in suckling rats and mice following intracranial inoculation.…”

Biology and Diseases of Rats

“…While experimental intracranial inoculations with the MHG virus resulted in paralysis in suckling rats (McConnell et al, 1964), this finding was not reproduced with RTV (Drake et al, 2011). No clinical signs have been associated with either experimental inoculation or natural infection, and the virus does not spread beyond the intestinal tract.…”

“…Isolation of the MHG virus (McConnell et al, 1964) and subsequently a virus designated NSG910 (Ohsawa et al, 2003) from rats provided further evidence of distinct rat cardioviruses. Isolation of the MHG virus (McConnell et al, 1964) and subsequently a virus designated NSG910 (Ohsawa et al, 2003) from rats provided further evidence of distinct rat cardioviruses.…”