Genetic properties of endemic Chinese porcine epidemic diarrhea
virus strains isolated since 2010
Received: 7 March 2013 / Accepted: 8 May 2013 / Published online: 25 June 2013
Ó Springer-Verlag Wien 2013
Abstract Acute diarrhea outbreaks caused by porcine
epidemic diarrhea virus (PEDV) have been observed in
various pig-breeding provinces of China since December
2010. Endemic strains of PEDV were isolated from different
areas, and the complete genome sequences of 10 isolates
were determined. Our objective in this study was to geneti-
cally characterize current Chinese ﬁeld isolates of PEDV to
better understand their epidemiology and genetic diversity.
Sequence analysis showed that 10 post-2010 isolates shared
high homology with each other and were always clustered
together with the virulent DR13 strains (South Korea) and/or
one earlier Chinese strain, CH-S, in phylogenetic analysis.
All post-2010 isolates possessed common sequence changes
in each gene. Our results suggest that current Chinese PEDV
isolates originated from either South Korean and/or Chinese
ancestors that underwent some genetic variation, thereby
forming a new PEDV genotype in China.
Porcine epidemic diarrhea virus (PEDV) is a positive-sense
single-stranded RNA virus belonging to group 1 of the genus
Alphacoronavirus, within the family Coronaviridae. The virus
is the etiological agent of porcine epidemic diarrhea (PED), an
acute and highly contagious enteric disease characterized by
watery diarrhea, vomiting, dehydration, and high mortality in
nursery piglets . PEDV was ﬁrst recognized as the causative
agent of PED in Belgium  and the United Kingdom in 1978
noﬂuorescence assays and serum neutralization tests, in 1984.
Bivalent killed or attenuated vaccines have been used to prevent
transmissible gastroenteritis (TGE) and PED in China since
then. Clinical PED outbreaks have reemerged in the major pig-
producing areas of China since December 2010, resulting in
major losses of suckling piglets. Morbidity rates between 90
and100 % have been observed, with mortalities of 70–100 %
on affected pig farms .
Heterogeneity of genomic sequences is believed to be
responsible for the diversity in PEDV pathogenicity. A
number of molecular investigations have been conducted,
revealing different levels of variation in nucleotide
sequences among PEDV isolates [5–7]. Because of
incomplete genomic information, most molecular epide-
miological analyses have targeted a single gene of PEDV.
To date, complete genome sequences of 18 PEDV strains,
including 10 endemic Chinese isolates, have been submitted
to the GenBank database [4, 8–19]. To better understand the
diversity, epidemiology and molecular characteristics of
PEDV isolates in China, we sequenced the complete gen-
ome of a virulent PEDV strain from Henan Province, China.
This isolate was from a suckling piglet that exhibited severe
diarrhea. We compared its genomic sequence with those of
other Chinese PEDV isolates and reference strains.
Materials and methods
Isolation and identiﬁcation of PEDV strain
PEDV strain CH/ZMDZY/11 was isolated from 2- to
3-day-old suckling piglets suffering from watery diarrhea
X. Wang Á B. Niu Á H. Yan Á D. Gao Á X. Yang Á L. Chen Á
H. Chang Á J. Zhao (&) Á C. Wang
College of Animal Science and Veterinary Medicine, Henan
Agricultural University, Zhengzhou, Henan Province 450002,
People’s Republic of China
Arch Virol (2013) 158:2487–2494