6Impey C S, Mead G C. Fate of salmonellas tract of chick pre-treated with a mature cecal microflora to increase colonization resistance[J]. J Appll bacterial,1989,66:841-844.
7S G Mellory, R M McCracken, S D Neill, et al. Control,prevention and eradiction of Salmonella enteridis infection in broiler and broiler breader[J].Vet Rec,1989,125:545-548.
8Lim S M, Jung H S, Kim M J, et al. Immunogenicity and safety of Vi capsular polysaccharide typhoid vaccine in healthy persons in Korea[J]. J Microbiol Biotechnol, 2007, 17 (4) : 611- 615.
9Zhou W Z, Koo H W, Wang X Y, et al. Revaccination with locally-produced vi typhoid polysaccharide vaccine among Chinese school-aged childrem safety and immunogenicity findings[J]. Pediatr Infect Dis J, 2007, 26(11) : 1001-1005.
10Ochiai R L, Acosta C J, Agtini M,et al. The use of typhoid vaccines in Asia: the DOMI experience[J]. Clin Infect Dis, 2007, 15(45) :34-38.