Differences in Salmonella enterica serovar Typhimurium strain invasiveness are associated with heterogeneity in SPI-1 gene expression

• DOI: 10.1099/mic.0.048496-0
• Publication Date: 2011-04-15T00:52:30Z
• Authors: Leann Clark; Charlotte A. Perrett; Layla Malt; Caryn Harward; Suzanne Humphrey; Katy A. Jepson; Isabel Martinez-A...; Laura J. Carney; Roberto M. La Rag...; Tom J. Humphrey; Mark A. Jepson
• Keywords: Salmonella enterica; Strain (injury)

Most studies on Salmonella enterica serovar Typhimurium infection focus strains ATCC SL1344 or NTCC 12023 (ATCC 14028). We have compared the abilities of these to induce membrane ruffles and invade epithelial cells. S . strain is less invasive induces smaller MDCK cells with SL1344. Since SPI-1 effector SopE present in absent from 12023, sopE mutants reduced invasiveness, we investigated whether due absence SopE. However, comparison + − strains, deletion expressing a plasmid revealed no consistent relationship between status relative invasiveness. Nevertheless, was closely correlated size ruffles. A P prgH – gfp reporter that relatively few population (and equivalent 14028) express other strains. Expression hilA mirrored SL1344, implicating signalling via transcription factor HilA heterogeneous expression The previously unrecognized heterogeneity invasiveness has important implications for infection.