Biological characterization and pathogenicity of a newly isolated Chinese highly virulent genotype GIIa porcine epidemic diarrhea virus strain

Abstract

Since 2010, continual outbreaks of highly virulent variants of porcine epidemic diarrhea virus (PEDV) belonging to genotype GII have led to serious economic losses for the Chinese swine industry. To better understand the biological characteristics and pathogenicity of the current prevalent Chinese PEDV field strains, in this study, a highly virulent Chinese genotype GIIa PEDV strain, CH/HBXT/2018, was isolated and serially propagated using Vero cells. Sequencing and phylogenetic analysis showed that strain CH/HBXT/2018 contained novel insertion and deletion mutations in the S gene region relative to the classical strain and belonged to the genotype GIIa, similar to other recently isolated PEDV strains from China and the United States. Pig infection studies indicated that the CH/HBXT/2018 strain was highly virulent in suckling piglets, and the median pig diarrhea dose (PDD 50 ) was 8.63 log 10 PDD 50 /3 mL at 7 days postinfection (DPI). The results of the present study are important for future PEDV challenge studies and the development of new PEDV vaccines based on prevalent field strains for the prevention and control of PED in China.Publisher's Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Isolation and characterization of a variant subgroup GII-a porcine epidemic diarrhea virus strain in China

“…The PEDV subgroups GII-a and GIIb in China are highly pathogenic to sucking piglets and exhibit serum cross-neutralization activity or cross-immune protection. The GII-a subgroup of PEDV was found to mediate better immune protection against challenges with the homologous PEDV strain than with the GIIb subgroup strain [5,18,22,23]. The objective of the current study was to reveal the molecular characteristics of the isolated subgroup GII-a PEDV strain HM2017, and evaluate its molecular characteristics and pathogenesis.…”

Establishment of method for dual simultaneous detection of PEDV and TGEV by combination of magnetic micro-particles and nanoparticles

“…For PEDV, once the infection reaches a certain level, it will spread in the whole pig farm and into surrounding areas if the prevention is not timely [5]. According to recent reports, PED is widely spread around the world, and the disease has spread to China, Japan, South Korea, Germany, Belgium, France and other countries or regions, the prevalence and incidence of the disease in Asia is far more serious than that in Europe [6].…”

Characterization, pathogenicity and protective efficacy of a cell culture-derived porcine deltacoronavirus

“…To determine the pathogenicity of the isolated virus in suckling piglets, infection experiments were performed using 4-day-old conventional suckling piglets, as described in our previous study (Zhang et al, 2019a). Briefly, pregnant PDCoV-naïve sows that tested seronegative for PDCoV in the indirect ELISA were selected from a commercial pig farm with no previous herd history of PDCoV infection.…”

“…All piglets were observed daily for clinical signs after inoculation. Rectal swabs were collected daily from all piglets, tested by real-time PCR and scored for fecal consistency as follows: 0 = normal; 1 = pasty; 2 = semiliquid; and 3 = liquid (Zhang et al, 2019a). The piglets were euthanized when obvious clinical symptoms were observed and fecal viral RNA shedding was detected in the rectal swab samples.…”

“…The piglets were euthanized when obvious clinical symptoms were observed and fecal viral RNA shedding was detected in the rectal swab samples. In addition, necropsy examinations of small intestinal tissues were also performed, as described previously (Zhang et al, 2019a). Intestinal samples were collected for hematoxylin and eosin (HE) staining and immunohistochemistry (IHC) examination.…”