Rat Parvovirus Type 1: the Prototype for a New Rodent Parvovirus Serogroup

Abstract

A newly recognized parvovirus of laboratory rats, designated rat parvovirus type 1a (RPV-1a), was found to be antigenically distinct. It was cloned, sequenced, and compared with the University of Massachusetts strain of rat virus (RV-UMass) and other autonomous parvoviruses. RPV-1a VP1 identity with these viruses never exceeded 69%, thus explaining its antigenic divergence. In addition, RPV-1a had reduced amino acid identity in NS coding regions (82%), reflecting phylogenetic divergence from other rodent parvoviruses. RPV-1a infection in rats had a predilection for endothelium and lymphoid tissues as previously reported for RV. Infectious RPV-1a was isolated 3 weeks after inoculation of infant rats, suggesting that it, like RV, may result in persistent infection. In contrast to RV, RPV-1a was enterotropic, a characteristic previously associated with parvovirus infections of mice rather than rats. RPV-1a also differed from RV in that infection was nonpathogenic for infant rats under conditions where RV infection causes high morbidity and mortality. Thus, RPV-1a is the prototype virus of an antigenically, genetically, and biologically distinct rodent parvovirus serogroup.

Viral Disease

“…VIRAL DISEASE mortality were observed in infant athymic rats inoculated oronasally with RV-Y than in euthymic rats, and included anemia and thrombocytopenia (Gaertner et al, 1989). Infectious RPV has been detected, following infection of infant, weanling, and adult rats, for 3 weeks, and viral DNA has been detected for up to 24 weeks (Ball-Goodrich et al, 1998;Ueno et al, 1997Ueno et al, , 1998, a finding consistent with persistent infection.…”

“…An antigenically distinct virus (H-1) was isolated in the following year by Toolan from a human tumor cell line that had been passed through rats and caused deformities in neonatal hamsters (Toolan et al, 1960). A third antigenically distinct virus, rat parvovirus (RPV), was isolated more recently from asymptomatic naturally infected rats (Ball-Goodrich et al, 1998). A similar parvovirus was identified by Japanese workers who initially referred to it as "rat orphan parvovirus" .…”

“…Hepatitis has been reported in adult rats with partial hepatectomy that were infected with H-1 (Ruffolo et al, 1966). RPV is not pathogenic after experimental inoculation (Ball-Goodrich et al, 1998;Ueno et al, 1997) and experimental inoculation with RMV has not been done.…”

“…RPV also infects renal tubular epithelium ( Fig. 13.3) and has been detected in urine (Ball-Goodrich et al, 1998;Ueno et al, 1997). While RV can infect intestinal mucosa and lead to fecal excretion (Lipton et al, 1972), the intestine does not appear to be a prominent target of RV.…”

“…While RV can infect intestinal mucosa and lead to fecal excretion (Lipton et al, 1972), the intestine does not appear to be a prominent target of RV. Intestinal infection is prominent with RPV, affecting predominantly the lamina propria, and RPV has been detected in feces (Ball-Goodrich et al, 1998;Ueno et al, 1996). RMV has been detected by PCR in the spleen, kidney, cecum, and mesenteric lymph nodes of naturally infected rats (Wan et al, 2006), suggesting RMV transmission occurs via urine or feces.…”