Fanfan Zhang

Newly Emerged Porcine Deltacoronavirus Associated With Diarrhoea in Swine in China: Identification, Prevalence and Full‐Length Genome Sequence Analysis

Summary To identify and characterize aetiologic agent(s) associated with an outbreak of a severe diarrhoea in piglets in Jiangxi, China, in March 2015, a nested reverse transcription–polymerase chain reaction (RT‐PCR) for the detection of porcine deltacoronavirus (PDCoV) was developed. A survey based on the nested RT‐PCR established indicated that the monoinfection of PDCoV (33.71%) and coinfection of PDCoV (19.66%) with porcine epidemic diarrhoea virus (PEDV) were common in diarrhoeal pigs in Jiangxi, China. A high prevalence of PDCoV (58.33%) in diarrhoeal samples which were PEDV negative was observed. The complete genome sequence of a representative PDCoV strain, PDCoV/CHJXNI2/2015, was determined. Phylogenetic analysis of complete genome and S protein sequences of PDCoV/CHJXNI2/2015 demonstrated that it was most closely related to Hong Kong and US PDCoVs. To our knowledge, this is the first report on the identification, prevalence, complete genome sequencing and molecular characterizations of PDCoV in diarrhoeal samples in pigs in China.

Comparison and evaluation of conventional RT-PCR, SYBR green I and TaqMan real-time RT-PCR assays for the detection of porcine epidemic diarrhea virus

Porcine epidemic diarrhea (PED) caused by porcine epidemic diarrhea virus (PEDV) is a highly contagious intestinal disease, resulting in substantial economic losses to the swine industry worldwide. In this study, three assays, namely a conventional reverse transcription-polymerase chain reaction (RT-PCR), a SYBR Green I real-time RT-PCR and a TaqMan real-time RT-PCR targeting the highly conserved M gene of PEDV, were developed and evaluated. Then, the analytical specificity, sensitivity and reproducibility of these assays were determined and compared. The TaqMan real-time RT-PCR was 100-fold and 10,000-fold more sensitive than that of the SYBR Green I real-time RT-PCR and the conventional RT-PCR, respectively. The analytical sensitivity of TaqMan real-time RT-PCR was 10 copies/μl of target gene and no cross amplification with other viruses tested was observed. With the features of high specificity, sensitivity, and reproducibility, the TaqMan real-time RT-PCR established in this study could be a useful tool for clinical diagnosis, epidemiological surveys and outbreak investigations of PED.

Whole-Genome Sequence of Duck Tembusu Virus Strain DTMUV/CH/2014, Isolated in China

ABSTRACT The whole-complete genome sequence of a strain of duck tembusu virus (DTMUV), DTMUV/CH/2014, affecting layer ducks in China, was determined and characterized. Compared with DTMUV sequences available in GenBank, DTMUV/CH/2014 has 3 amino acid mutations located in the capsid, prM, and NS3 genes of DTMUV/CH/2014.

Complete Genome Sequence of a Recombinant Porcine Epidemic Diarrhea Virus Strain, CH/JXJA/2017, Isolated in Jiangxi, China, in 2017

ABSTRACT The full-length genome sequence of a variant of porcine epidemic diarrhea virus (PEDV), that of strain CH/JXJA/2017, was highly homologous to CH/ZMDZY/11, a highly virulent Chinese PEDV strain. CH/JXJA/2017 had a distant relationship with the attenuated CV777 vaccine strain, but the insertion sites of the S1 gene were similar to those of the recombinant strain of CH/ZMDZY/11.

Complete Genome Sequence of a Porcine Kobuvirus Variant Strain from Jiangxi, China

ABSTRACT The complete genome sequence of a porcine kobuvirus (PKoV) variant strain, CH/KB-1/2014 from Jiangxi, China, with a 90-nucleotide deletion in the 2B gene, was determined and characterized. This study provides a better understanding of the molecular characteristics and evolution of PKoV in Jiangxi, China.

Full-Length Genome Sequence of a Variant Porcine Epidemic Diarrhea Virus Strain, CH/GDZQ/2014, Responsible for a Severe Outbreak of Diarrhea in Piglets in Guangdong, China, 2014

ABSTRACT The full-length genome sequence of a variant porcine epidemic diarrhea virus (PEDV) strain, CH/GDZQ/2014, was determined. The isolate was a variant strain with a relatively far relationship with the PEDV strains previously identified in the same area between 2011 and 2012 and was genetically distinct from the CV777-based vaccine strain currently being used in China.

Altered Gut Microbiota Profiles in Sows and Neonatal Piglets Associated with Porcine Epidemic Diarrhea Virus Infection

Porcine epidemic diarrhea virus (PEDV) is a devastating cause of diarrhea in pigs worldwide. Most of studies have focused on molecular and pathogenic characterization of PEDV, whereas there were limited studies in understanding the role of gut microbiota (GM) in viral-associated diarrhea. Here, using the Illumina MiSeq platform, we examined and compared the impact of PEDV infection on the GM of sows and their piglets less than 10 days old. Our results showed that PEDV caused alternations in the structure and abundance of GM from levels of phylum to genus, and even species. For sows, a significant decrease of observed species was found in diarrheal sows than that in healthy sows (p < 0.05). The unweighted and weighted UniFrac distances also revealed considerable segregations of GM structure among healthy, asymptomatic, and diarrheal sows. For piglets, Bacteroidetes, the dominant bacteria in healthy piglets, were replaced by Firmicutes in asymptomatic and diarrheal piglets. The abundances of Fusobacteria and Proteobacteria were also remarkably increased in asymptomatic piglets and diarrheal piglets when compared to those of the healthy piglets. Our findings demonstrated that PEDV infection caused severe perturbations of GM, reduced probiotic bacteria, and enriched pathogenic bacteria.