Fimbria

Three types of thread-like appendages may be found growing from bacterial cells flagella, pili (fimbriae) and F-pili (sex strands). 

A. Bacterial appendages (pili. fimbriae) Pseudomonas fluorescens 86... 

S. J. Vesper, Production of pili (fimbriae) by Pseudomonmas fluorescens and correlation with attachment to corn roots. Applied and Environmental Microbiology 53 1397 (1987). 

Recently, a novel class of prostaglandin derivatives, PG-1,15-lactones (Fig. 1) of both E [16] and F [17] series, has been reported to occur in the opisthobranch mollusc Tethys fimbria, along with smaller amounts of some of the corresponding PGs. Some lactones were present mainly in the mucous secretion and dorsal appendages known as cerata, while others were more abundant in the mantle. Fatty acid esters of PGF-1,15-lactones (C9 and Cu) were found only in T. fimbria eggmasses and reproductive glands (ovotestis). The structural variety of the lactones and the data on their distribution in the body... 

Fig. 1. Prostaglandin 1,15-lactones and prostaglandins isolated from Tethys fimbria...

PGF2a-1,15-lactone-11-acetate (140) and PGF3ct-l,15-lactone-11-acetate (141) [174-176]. Further, T. fimbria reproductive tissues and egg masses contained a relatively high concentration of saturated and unsaturated long-chain fatty acid esters of PGF2 and PGF3(r (142, 143) [177, 178]. 

T. K. Lindhorst, S. Kotter, U. Krallmann-Wenzel, and S. Ehlers, Trivalent a-D-mannoside clusters as inhibitors of type-1 fimbriae-mediated adhesion of Escherichia coli Structural variation and biotinylation, J. Chem. Soc. Perkin Trans., 1 (2001) 823-831. 

Nataro JP, DengY, ManevalDR, German AL, Martin WC, Levine MM Aggregative adherence fimbriae I of enteroaggregative Escherichia coli mediate adherence to HEp-2 cells and hemagglutination of human erythrocytes. Infect Immun 1992 60 2297-2304. 

Nataro JP, Yikang D, Giron JA, Savarino SJ, Kothary MH, Hall R Aggregative adherence fimbria I expression in enteroaggregative Escherichia coli requires two unlinked plasmid regions. Infect Immun 1993 61 1126-1131. 

An important virulence factor of bacteria is their ability to adhere to urinary epithelial cells by fimbriae, resulting in colonization of the urinary tract, bladder infections, and pyelonephritis. Other virulence factors include hemolysin, a cytotoxic protein produced by bacteria that lyses a wide range of cells... 

Cassel, J. C., Duconseitle, E., Jeltsch, H. and Witt, B. (1997) The fimbria-fomix/cingular bundle pathways a review of neurochemical and behavioural approaches using lesions and transplantation techniques. Prog. Neurobiol. 51, 663-716. 

The initial adherence of pathogens to host cell surfaces is considered an essential step in colonization and infection (Savage, 1977, 1984). Therefore, identifying the bacterial molecules that mediate adherence has been a major area of research, especially since these molecules may serve as targets for anfi-adherence strategies. As discussed previously (Section VI), the detailed interactions between a pathogen and a host cell are often mediated by proteinaceous surface structures on the bacterial surface. These bacterial proteins are referred to as adhesins (Finlay and Falkow, 1989), and are most often foimd on the tips of bacterial fimbriae or pili (fimbrial adhesins), but may also be anchored in the bacterial membrane so that it can be presented on the bacterial outer membrane (afimbrial adhesins) (Sharon and Ofek, 1986). Models of fimbrial and afimbrial adhesins of some human pathogens are discussed here. 

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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