Intestinal and extra-intestinal pathogenicity of a bovine reassortant rotavirus in calves and piglets

Abstract

Despite the impact of bovine group A rotaviruses (GARVs) as economically important and zoonotic pathogens, there is a scarcity of data on cross-species pathogenicity and extra-intestinal spread of bovine reassortant GARVs. During the course of characterizing the genotypes of all 11 genomic segments of bovine GARVs isolated from diarrheic calves in South Korea, a unique G6P[7] reassortant GARV strain (KJ9-1) was isolated. The strain harbors five bovine-like gene segments (VP7: G6; VP6: I2; VP1: R2; VP3: M2; NSP2: N2, and NSP4: E2), five porcine-like gene segments (VP4: P[7]; NSP1: A1; NSP3: T1, and NSP5: H1), and one human-like gene segment (VP2: C2). To investigate if this reassortant strain possessed cross-species pathogenicity in calves and piglets, and could induce viremia and extra-intestinal spread in calves, colostrum-deprived calves and piglets were experimentally inoculated with the KJ9-1 strain. The KJ9-1 strain caused severe diarrhea in experimentally infected calves with extensive intestinal villous atrophy, but replicated without causing clinical symptoms in experimentally infected piglets. By SYBR Green real-time RT-PCR, viral RNA was detected in sera of the calves at post-inoculation day (PID) 1, reaching a peak at PID3, and then rapidly decreasing from PID4. In addition, viral RNA was detected in the mesenteric lymph node, lungs, liver, choroid plexus, and cerebrospinal fluid. An immunofluorescence assay confirmed viral replication in the extra-intestinal organs and tissues of virus-inoculated calves. The data indicates that the homologous/heterologous origin of the NSP4 gene segment (E2 genotype), may play a key role in the ability to cause diarrhea in calves and piglets.

Persistence of the rotavirus A genome in mesenteric lymph nodes of cattle raised on farms

“…The presence of RVA in MLNs has so far been reported in experimental animal models (Brown & Offit, 1998;Crawford et al, 2006;Dharakul et al, 1988;Fenaux et al, 2006;Kim et al, 2011;Mossel & Ramig, 2003; Park et al, Genetic analyses showed that all strains for which the genome was detected in MLNs from autopsied calves and healthy adult cattle were classified as G and/or P (possible) genotypes generally prevalent in bovines (Tables 2 and 3). Also, in most of the cattle that had RVA genomes in both MLNs and intestinal contents, the strains in intestinal contents were genetically identical to those in MLNs.…”

“…Also, previous studies on the dynamics of RVA in extra-intestinal organs in calves under experimental conditions showed that MLNs had the highest viral RNA copy number amongst extra-intestinal organs (Kim et al, 2011;Park et al, 2013Park et al, , 2014. It was also reported that viral RNA copy numbers in MLNs were comparable to or sometimes higher than those in faeces through the duration of experimental infection for 14 days.…”

“…However, there has been an increasing number of reports of infectious RVA and the viral antigen being detected in sera and various organs, such as mesenteric lymph nodes (MLNs), lungs and livers in humans and animals (Blutt et al, 2003;Crawford et al, 2006;Dharakul et al, 1988;Fenaux et al, 2006;Lynch et al, 2003;Mossel & Ramig, 2003). In experimental animal models, RVA has been detected not only in the gastrointestinal tract but also in extra-intestinal organs, indicating that the virus is able to spread systemically from the gastrointestinal tract (Crawford et al, 2006;Fenaux et al, 2006;Kim et al, 2011;Mossel & Ramig, 2003;Park et al, 2013Park et al, , 2014.…”

Prevention of Coxsackieviruses and Rotaviruses Infections In Vivo with Methanol Extract of Dodonaea Viscosa

“…At 7 days post-infection, four mice from each group were killed and the small intestine of each group were collected for histopathological examinations. The changes in small intestinal were scored as described by Kim et al [41]. Based on the ratios of villi/crypt (V/C) which estimated as follows: 0 = normal, 1 = mild, 2 = moderate, 3 = marked and 4 = severe.…”

Pathogenicity of porcine G9P[23] and G9P[7] rotaviruses in piglets

“…In children who died during RVA infection, RVA antigens and viral RNA were detected in the extraintestinal organs and tissues including the central nervous system, liver, lung, spleen, heart, kidney, testis, and bladder (Blutt and Conner, 2007;Lynch et al, 2001;Pager et al, 2000;Ramig, 2004;Riepenhoff-Talty et al, 1996;Zheng et al, 1991). It has been clearly demonstrated that RVAs cause not only gastrointestinal but also systemic infections in experimental animal models (Ciarlet et al, 2002;Crawford et al, 2006;Fenaux et al, 2006;Kim et al, 2011Kim et al, , 2012bPetersen et al, 1998).…”