Development of a human rotavirus induced diarrhea model in Chinese mini-pigs.
OBJECTIVE
To establish a new animal model for the research of human rotavirus (HRV) infection, its pathogenesis and immunity and evaluation of potential vaccines.


METHODS
5-d, 30-d and 60-d-old Chinese mini-pigs, Guizhou and Bamma, were inoculated with a single oral dose of attenuated strain Wa, G1, G3 of HRV, and PBS (control), respectively, and fecal samples of pigs from 0 to 7 d post infection (DPI) were collected individually. Enzyme linked immunosorbent assay was used to detect HRV antigen in feces. The HRV was tested by real-time PCR (RT-PCR). The sections of the intestinal tissue were stained with hematoxylin and eosin to observe the morphologic variation by microscopy. Immunofluorescence was used to determine the HRV in intestinal tissue. HRV particles in cells of the ileum were observed by electron micrography.


RESULTS
When inoculated with HRV, mini-pigs younger than 30 d developed diarrhea in an age-dependent manner and shed HRV antigen of the same inoculum, as demonstrated by RT-PCR. Histopathological changes were observed in HRV inoculated mini-pigs including small intestinal cell tumefaction and necrosis. HRV that was distributed in the small intestine was restricted to the top part of the villi on the internal wall of the ileum, which was observed by immunofluorescence and transmission electron microscopy. Virus particles were observed in Golgi like follicles in HRV-infected neonatal mini-pigs. Guizhou mini-pigs were more sensitive to HRV than Bamma with respect to RV antigen shedding and clinical diarrhea.


CONCLUSIONS
These results indicate that we have established a mini-pig model of HRV induced diarrhea. Our findings are useful for the understanding of the pathogenic mechanisms of HRV infection.
Jin-Tao Li, Hong-Xia Guo, Jiang-Bo Han, Nan Ye, Tian-Tian Yu, Institute of Tropical Medicine, Third Military Medical University, Chongqing 400038, China.
Jin-Tao
JT
Li
Jin-Tao Li, Hong-Xia Guo, Jiang-Bo Han, Nan Ye, Tian-Tian Yu, Institute of Tropical Medicine, Third Military Medical University, Chongqing 400038, China.
Jing
J
Wei
Jin-Tao Li, Hong-Xia Guo, Jiang-Bo Han, Nan Ye, Tian-Tian Yu, Institute of Tropical Medicine, Third Military Medical University, Chongqing 400038, China.
Hong-Xia
HX
Guo
Jin-Tao Li, Hong-Xia Guo, Jiang-Bo Han, Nan Ye, Tian-Tian Yu, Institute of Tropical Medicine, Third Military Medical University, Chongqing 400038, China.
Jiang-Bo
JB
Han
Jin-Tao Li, Hong-Xia Guo, Jiang-Bo Han, Nan Ye, Tian-Tian Yu, Institute of Tropical Medicine, Third Military Medical University, Chongqing 400038, China.
Nan
N
Ye
Jin-Tao Li, Hong-Xia Guo, Jiang-Bo Han, Nan Ye, Tian-Tian Yu, Institute of Tropical Medicine, Third Military Medical University, Chongqing 400038, China.
Hai-Yang
HY
He
Jin-Tao Li, Hong-Xia Guo, Jiang-Bo Han, Nan Ye, Tian-Tian Yu, Institute of Tropical Medicine, Third Military Medical University, Chongqing 400038, China.
Tian-Tian
TT
Yu
Jin-Tao Li, Hong-Xia Guo, Jiang-Bo Han, Nan Ye, Tian-Tian Yu, Institute of Tropical Medicine, Third Military Medical University, Chongqing 400038, China.
Yu-Zhang
YZ
Wu
D000818:Animals; D000956:Antigens, Viral / Q000032:analysis; D003967:Diarrhea / Q000209:etiology*; D004195:Disease Models, Animal; D006801:Humans; D007421:Intestine, Small / Q000473:pathology / Q000821:virology; D012400:Rotavirus Infections / Q000150:complications* / Q000473:pathology; D013552:Swine; D013556:Swine, Miniature
D000956:Antigens, Viral
Animal model; Chinese mini-pigs; Diarrhea; Human rotavirus; Intestine