Study on characteristic of human rotavirus strains G9P8 on cell culture

ABSTRACT

Background: In recent years, the rotavirus diarrhea increased significantly in Vietnam, an estimated 50%-70% of children\u2019s hospitalization for diarrhea in 2005. The virus subtype causing disease mainly in Vietnam today was not only G1, G2, G4, like other countries in the world but also the rare strain was G9. Objectives: to isolate G9 rotavirus strains on MA104 cell culture; to selecting G9 rotavirus which developing well on MA104 cells. Subjectives and Method: an experimental research in the laboratory. 20 stool samples derived from 20 children with acute diarrhea caused by rotavirus G9P8 (using RT-PCR method). The samples were processed according to standards of the Centers for disease control and prevention (CDC), Atlanta, USA. Results: eight out of 20 human rotavirus strains G9P8 were positive on Ma104 cell suspension after 3 consecutive cultures (OD indexes of these sample were over 0.100,sample No 2 had the highest OD (1.347)). Sample No 2 was chosen for the first time cloning (25 clones, 17/25 with OD>0.100). And clone No 16 was selected for the second purifying (25 clones, 24/25 with OD>0.100). Ten out of 25 clones in the second time were adapted on monolayer Ma104 cell culture and only clone No 14 and No 18 with highest OD (2.648 and 2.644, respectively) will be used for next studies. Conclusions: cloning method was a basic method for adapting rotavirus clone on cell cultured. Rate of G9P8 rotavirus strain which isolated on Ma104 cells\ufffd?suspension was relatively high. Among the second time clones, 2/10 samples adapted on Ma104 cells with high OD.