ORF3adeletion in field strains of porcine-transmissible gastroenteritis virus in China: A hint of association with porcine respiratory coronavirus

Abstract

Porcine-transmissible gastroenteritis virus (TGEV) is a pathogenic coronavirus responsible for high diarrhoea-associated morbidity and mortality in suckling piglets. We analysed the TGEV ORF3 gene using nested polymerase chain reaction and identified an ORF3a deletion in three field strains of TGEV collected from piglets in China in 2015. Eight TGEV ORF3 sequences were obtained in this study. Phylogenetic tree analysis of ORF3 showed that the eight TGEV ORF3 genes all belonged to the Miller cluster. CH-LNCT and CH-MZL were closely correlated with Miller M6, while CH-SH was correlated with Miller M60. These results thus indicate that the existence of Miller, as well as the Purdue cluster, in Chinese field strains of TGEV. Furthermore, we found the first evidence for a large deletion in ORF3 resulting in the loss of ORF3a, previously reported in porcine respiratory coronavirus, in three field strains (CH-LNCT, CH-MZL, and CH-SH) of TGEV. The results of the present study thus provide important information regarding the underlying evolution mechanisms of coronaviruses.

Resistance to coronavirus infection in amino peptidase N-deficient pigs

“…Other coronaviruses may also use ANPEP as an entry mediator. Due to genome similarity porcine respiratory coronavirus (a TGEV mutant) (Zhang et al 2017 ) likely uses ANPEP, and other less related viruses such as porcine deltacoronavirus, another swine enteropathogen, may use ANPEP to gain entry into the cell (Li et al 2018 ). Clearly additional whole animal studies need to be conducted to better understand the molecules that these viruses use to gain entry.…”

A G3P[13] porcine group A rotavirus emerging in China is a reassortant and a natural recombinant in the VP4 gene

“…Many types of viruses cause diarrhoea in animals, including TGEV (Zhang, Zhu, Zhu, Chen et al., ), swine enteric coronaviruses (SeCoVs) (Belsham et al., ), PEDV (Lohse et al., ; Tian et al., ; Zhang, Tian et al., ), porcine deltacoronavirus (Lee et al., ; Mai et al., ; Saeng‐Chuto et al., ) and rotaviruses (Kim et al., ). Rotaviruses cause acute dehydrating diarrhoea in various hosts, including children and young animals (Jiang, Liu, & Tan, ).…”

Isolation and Characterization of a Porcine Transmissible Gastroenteritis Coronavirus in Northeast China

“…Since then, the disease always happened in swine-producing areas of the world (1,3), and reported many times in China in recent years (4)(5)(6)(7)(8). Epidemiological investigations have shown that TGEV is often present in the spring and autumn in the northeast of China, sometimes in mixed infections with other diarrhea virus, and caused viral enteritis and severe diarrhea in all ages of pigs, especially with high mortality in suckling piglets (9,10).…”