Fimbrial adhesins Salmonella

Recently, a non-fimbrial adhesin, SiiE, has been identified in S. enterica serovar T)q)himurim. Although little is known about SiiE, it has been found to mediate contact-dependent adhesion to HeLa cell surfaces (Gerlach et al., 2007). SiiE is a type 1 secretion system (TISS) secreted protein encoded m the Salmonella pathogenicity island 4 and might functionally resemble the type 1 fimbrial adhesins. More work is needed to elucidate the true role of SiiE in adherence in vivo. 

Baumler, A. J., Tsolis, R. M., and Heffron, F. (1997). Fimbrial adhesins of Salmonella typhimurium. Role in bacterial interactions with epithelial cells. Adv. Exp. Med. Biol. 412,149-158. 

Gerlach, R. G., Jackel, D., Stecher, B., Wagner, C., Lupas, A., Hardt, W.-D., and Hensel, M. (2007). Salmonella pathogenicity island 4 encodes a giant non-fimbrial adhesin and the cognate type 1 secretion system. Cell. Microbiol. 9,1834-1850. 

The adherence mechanisms involved in Salmonella infection have been studied in great deal. Disease associated with S. enterica serovars is initiated by attachment to and invasion of hosf cells, followed by subse-quenf inflammation of the lamina propria and lymph nodes (Darwin and Miller, 1999). Several genetically defined fimbrial or piliar adhesins con-tribufe fo fhe initial attachment and the overall infection process of Salmonella. Some of fhese include t)q)e 1 fimbriae (Fim), plasmid-encoded (PE) fimbriae, long polar (LP) fimbriae, and thin aggregative fimbriae (curli). However, many ofher putative fimbrial operons have been identified within various S. enterica serovar genomes, but the expression of fhese proteins is currently undefined. 

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