Porcine rotavirus C in pigs with gastroenteritis on Thai swine farms, 2011–2016

Swine are economically important food animals, but highly contagious porcine epidemic diarrhea virus (PEDV) and rotavirus can afflict pig herds and contribute significantly to piglet morbidity and mortality. While there have been studies on rotavirus group A (RVA) in Thailand, reports of rotavirus group C (RVC) are limited. Here, we aimed to identify the prevalence of RVC circulating on Thai commercial swine farms. We analyzed 769 feces and intestine mucosal contents of pigs affected with diarrhea between 2011 and 2016 using RT-PCR specific for the PEDV spike (S), rotavirus glycoprotein (G) VP7, and protease-sensitive protein (P) VP4 genes. We found that 6.6% (51/769) of samples tested positive for RVC, of which 11 samples were co-infected with RVA and four samples were co-infected with PEDV. Three samples tested positive for all three viruses. Phylogenetic analysis of the VP7 gene showed that the most frequent RVC genotype was G1, which grouped with the prototypic RVC Cowden strain. While G6 and G9 were also common, G3 was relatively rare. Analysis of the VP4 gene revealed that the most common P type was P[5], followed by P[4], P[7], and P[1]. In all, there were six G/P combinations (G6P[5], G1P[1], G1P[4], G1P[5], G9P[4], and G9P[7]), of which G6P[5] was the most predominant

Phylogenetic analysis of the nucleotide sequences of the VP4-VP2 region from EV-positive AGE samples.

<p>Phylogenetic tree was constructed using the neighbor-joining method implemented in MEGA (version 5). Bootstrap resampling values >70 are indicated at the nodes. The scale bar indicates the number of substitutions per site. Black dots denote EV obtained from samples with multiple viruses. Blue, EV-A; red, EV-B; green, EV-C; purple, EV-D; yellow, rhinovirus.</p

AGE samples tested positive for diverse genotypes of RV, NV, and ADV.

<p>The genotype distribution of (A) RV based on the VP7 and VP4 genes, (B) NV based on the RdRp/VP1 region, and (C) ADV based on the hexon gene.</p

Characteristics of the cohorts with (AGE) or without (HFMD) diarrhea in this study.

<p>Characteristics of the cohorts with (AGE) or without (HFMD) diarrhea in this study.</p