Genetic Heterogeneity and Mutated PreS Analysis of Duck Hepatitis B Virus Recently Isolated from Ducks and Geese in China

Abstract

In this study, we detected 12 duck and 11 goose flocks that were positive for duck hepatitis B virus (DHBV) using polymerase chain reaction and isolated 23 strains between 2020 and 2022 in China. The complete genomes of goose strains E200801 and E210501 shared the highest identity (99.9%), whereas those of strains Y220217 and E210526 shared the lowest identity (91.39%). The phylogenetic tree constructed based on the genome sequences of these strains and reference strains was classified into three major clusters: the Chinese branch DHBV-I, the Chinese branch DHBV-II, and the Western branch DHBV-III. Furthermore, the duck-origin strain Y200122 was clustered into a separate branch and was predicted to be a recombinant strain derived from DHBV-M32990 (belonging to the Chinese branch DHBV-I) and Y220201 (belonging to the Chinese branch DHBV-II). Additionally, preS protein analysis of the 23 DHBV strains revealed extensive mutation sites, almost half of which were of duck origin. All goose-origin DHBV contained the mutation site G133E, which is related to increased viral pathogenicity. These data are expected to promote further research on the epidemiology and evolution of DHBV. Continuing DHBV surveillance in poultry will enhance the understanding of the evolution of HBV.

The Development of a Multienzyme Isothermal Rapid Amplification Assay to Visually Detect Duck Hepatitis B Virus

“…Through the artificial challenging test over 72 days, the livers of ducks infected with G133E DHBV demonstrated acute injury such as enhanced periportal cell growth, massive hepatocytes lysis, and apoptosis compared with the ducks that were infected with wild-type DHBV; additionally, there were greater losses of mean body weights in the birds infected with G133E DHBV compared with the birds with wild-type DHBV [7]. In another study previously reported by our group, a total of 540 serum samples were collected from 23 duck farms and 31 goose farms in Central and Eastern China from 2020 to 2022, and the positive rates in duck and goose flocks reached 52.2% and 35.5%, respectively [8]. And a genome sequence analysis suggested that the 11 obtained geese-originated DHBV strains were all of the G133E type, and 5 of the 12 duck-originated strains were DHBV variants harboring the G133E mutation site in the preS protein, which further indicates that DHBV with increased virulence and transmission ability was highly prevalent in Chinese ducks, and even geese [8].…”

“…In another study previously reported by our group, a total of 540 serum samples were collected from 23 duck farms and 31 goose farms in Central and Eastern China from 2020 to 2022, and the positive rates in duck and goose flocks reached 52.2% and 35.5%, respectively [8]. And a genome sequence analysis suggested that the 11 obtained geese-originated DHBV strains were all of the G133E type, and 5 of the 12 duck-originated strains were DHBV variants harboring the G133E mutation site in the preS protein, which further indicates that DHBV with increased virulence and transmission ability was highly prevalent in Chinese ducks, and even geese [8]. Even though there were no remarkable clinical symptoms, these findings imply that the health of ducks and geese was also influenced by DHBV infection, and the global poultry industry may suffer financial losses due to DHBV infection.…”

“…The newly developed MIRA assay method for DHBV detection only requires one pair of primer sets, which has a simpler design than the widely used LAMP assay. More importantly, the replication manner, persistent infection, and wide prevalence of DHBV caused the extensive genetic diversity and heterogeneity of the virus, including multiple site mutations and complex inner genotype and intra genotype recombinations [6,8]. In our previous report about a LAMP assay developed for DHBV detection, we compared it with SYBR green-dye-based quantitative PCR for DHBV detection in clinical samples [12,14].…”