Cronobacter sakazakii is in the Cronobacter genus (previously known as Enterobacter sakazakii), which consists in total of seven species. C. sakazakii strains in the clonal complex 4 (CC4), including sequence type 4 (ST4), have been strongly associated with neonatal meningitis. In recent years, research on this organism has made substantial progress using improved identification and molecular methods including multilocus sequence typing. A number of virulence traits have been proposed but have not been studied to date with respect to detailed aspects of the virulence potential and host response. Therefore this project compared 34 isolates of C. sakazakii made up of clonal complex 4 (CC4; 21 isolates) and non-clonal complex 4 (13 isolates) strains for their virulence potential, and investigated whether CC4 strains have the ability to overcome the host barriers more than the other sequence types. The attachment and invasion of mammalian intestinal and brain cells by these strains were evaluated using colorectal adenocarcinoma epithelial cells (Caco-2), human brain microvascular endothelial cells (HBMEC), and rat brain capillary endothelial (rBCEC4) cell lines. Furthermore, the ability of the organism to translocate through different cell lines, including Caco-2 and HBMEC, was assessed
