Porcine rotaviruses belong to the genus rotavirus in the family Reoviridae. Porcine rotaviruses have so far been divided into four serogroups, named as A, B, C, and E. Rotavirus appears as a wheel-like particle under negative staining electronic microscopy (EM). The rotavirus genome is composed of 11 double-stranded RNA segments, and the sizes range from 0.6 to 3.3 kb. VP4, VP6, and VP7 have recently become the focuses of research due to their unique biological functionalities. Based on the antigenicity of VP4 and VP7, group A rotavirus is divided into genotypes P and G. Group A porcine rotavirus is consist of 37P genotypes and 27 G genotypes.
The incubation period for acute porcine rotavirus infections in piglets usually ranges from 16 to 24h, the clinical symptoms for infections include depression, diarrhea, and a large amount of mucosal feces. Porcine rotaviruses mainly exist in the intestines of piglets at beginning of infection excrete into feces and spread throughout to other piglets by a fecal/oral route. Porcine rotavirus is very resistant to surrounding environment and disinfectants and viral infectivity in feces can last for 7-9 months at room temperature.
In last two years, pig herds with serious diarrhea have been reported in a large number of areas of China. During disease survey and diagnosis, a rotavirus, HN-001, was isolated from fecal samples of young piglet with acute diarrhea in Henan province of China. The virus isolation, molecular characterization, and its pathogenic evaluation in piglets will be described.
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