Cell adherence-promoted activity of Plesiomonas shigelloides GroEL

Previously, it has been demonstrated that the invasion of Caco-2 cells by Plesiomonas shigelloides induces apoptotic cell death. Therefore, the attachment to and colonization of eukaryotic intestinal host cells by P. shigelloides are important steps in causing pathogenicity. In this study, the participation of P. shigelloides GroEL in the attachment of P. shigelloides was examined. The groESL operon of P. shigelloides was isolated by PCR. The nucleotide sequence of the groESL operon of P. shigelloides revealed two ORFs of 294 nucleotides for groES and 1647 nucleotides for groEL. Cell fractionation and immunostaining experiments suggested that the GroEL of P. shigelloides was associated with the bacterial cell surface. The expression of the groEL gene was upregulated during the attachment and apoptosis-induction stages, and the expression of the protein was also induced during the attachment stage. Furthermore, GroEL efficiently promoted the attachment of P. shigelloides to Caco-2 cells, as measured by a FACSCalibur flow cytometer. These results demonstrated that GroEL has a positive influence on the attachment of P. shigelloides to Caco-2 cells.