Characterization of a Novel Rat Hepatitis E Virus Isolated from an Asian Musk Shrew (Suncus murinus).

Huimin Bai,Tian-Cheng Li,Juan Su,Dawei Guan,Wei Li,Changwen Ke,Yuriko Suzaki,Yasushi Ami,Naokazu Takeda,Masamichi Muramatsu

doi:10.3390/v12070715

Abstract

The Asian musk shrew (shrew) is a new reservoir of a rat hepatitis E virus (HEV) that has been classified into genotype HEV-C1 in the species Orthohepevirus C. However, there is no information regarding classification of the new rat HEV based on the entire genome sequences, and it remains unclear whether rat HEV transmits from shrews to humans. We herein inoculated nude rats (Long-Evans rnu/rnu) with a serum sample from a shrew trapped in China, which was positive for rat HEV RNA, to isolate and characterize the rat HEV distributed in shrews. A rat HEV strain, S1129, was recovered from feces of the infected nude rat, indicating that rat HEV was capable of replicating in rats. S1129 adapted and grew well in PLC/PRF/5 cells, and the recovered virus (S1129c1) infected Wistar rats. The entire genomes of S1129 and S1129c1 contain four open reading frames and share 78.3–81.8% of the nucleotide sequence identities with known rat HEV isolates, demonstrating that rat HEVs are genetically diverse. We proposed that genotype HEV-C1 be further classified into subtypes HEV-C1a to HEV-C1d and that the S1129 strain circulating in the shrew belonged to the new subtype HEV-C1d. Further studies should focus on whether the S1129 strain infects humans.

Highlights

Hepatitis E virus (HEV) is a non-enveloped virus containing a positive-sense, single-strandRNA as the genome, and has been classified into the family Hepeviridae, which includes two genera, Orthohepevirus and Piscihepevirus [1]
We isolated a novel rat hepatitis E virus (HEV) strain, S1129, through in vivo amplification by inoculating a nude rat with a serum sample derived from a rat HEV RNA-positive shrew trapped in
Phylogenetic analysis demonstrated that this strain was highly divergently constellated in known rat HEV isolates, and we proposed that HEV-C1 was further classified into subtypes HEV

Summary

Introduction

Hepatitis E virus (HEV) is a non-enveloped virus containing a positive-sense, single-strandRNA as the genome, and has been classified into the family Hepeviridae, which includes two genera, Orthohepevirus and Piscihepevirus [1]. The Orthohepevirus genus includes four species, Orthohepevirus A to D (HEV-A to HEV-D). HEV-A includes eight genotypes of HEV (G1 to G8 HEV), which are detected in humans, monkeys, pigs, wild boars, deer, mongooses, rabbits, and camels [1,2,3,4,5,6,7,8,9]. HEV-B includes avian HEVs exclusively, HEV-D includes several bat HEV strains [10,11]. HEV-C is grouped into two genotypes, HEV-C1, which includes rat HEV, and HEV-C2, which includes ferret HEV [12,13]. In addition to HEV-C1 and -C2, two putative genotypes, HEV-C3 and -C4, were recently found in rodents and kestrels [14,15]

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Conclusion