Molecular analysis of the genes mediating Salmonella invasion.
To identify invasion determinants, a genomic library of Salmonella typhimurium was cloned into a cosmid vector, pLA2917. A clone, pSI623 which was invasive for HEp-2 and Henle-407 epithelial cells, was subcloned into a plasmid vector, pGEM-7Z to define the invasion genes. The subclone, pSV6235 containing a 4.5 kbp fragment of the Salmonella genomic region, was highly invasive for HEp-2 and Henle-407 cells, compared with other subclones whose Salmonella genomic regions are 7.4, 6.3, 5.5 and 1.4 kbp, respectively. This study reflects that the invasion efficiency of the host strain, Escherichia coli to HEp-2 and Henle-407 cell lines was significantly increased by the introduction of the genomic region of the virulent S. typhimurium. Restriction enzyme analysis showed that there was a single PstI site on the 27 kbp of Salmonella genomic region of pSI623, and no PstI site was found on the 4.5 kbp of genomic region of pSV6235. This finding suggests that the invasion related genes different from the inv and spa gene clusters which were identified in S. typhimurium, may exist in genomic DNA of S. typhimurium.
Park
J U
JU
Biomedical and Health Sciences, Royal Melbourne Institute of Technology, Australia.
D002460:Cell Line; D003001:Cloning, Molecular; D003360:Cosmids; D004926:Escherichia coli / Q000235:genetics; D005798:Genes, Bacterial; D005822:Genetic Vectors; D015698:Genomic Library; D006801:Humans; D005810:Multigene Family; D010957:Plasmids; D015183:Restriction Mapping; D012486:Salmonella typhimurium / Q000235:genetics* / Q000472:pathogenicity*; D014774:Virulence / Q000235:genetics