Klebsiella pneumoniae CG43, a heavy encapsulated liver abscess isolate, mainly expresses type 3 fimbriae. Type 1 fimbriae expression was only apparent in CG43S3ΔmrkA (the type 3 fimbriae-deficient strain). The expression of type 1 fimbriae in CG43S3ΔmrkA was reduced by deleting the fimK gene, but was unaffected by removing the 3' end of fimK encoding the C-terminal EIL domain (EILfimK). Quantit...

The capsular polysaccharide and type 1 fimbriae are two of the major surface-located virulence properties associated with the pathogenesis of Klebsiella pneumoniae. The capsule is an elaborate polysaccharide matrix that encases the entire cell surface and provides resistance against many host defense mechanisms. In contrast, type 1 fimbriae are thin adhesive thread-like surface organelles that ...

Phagocytosis of Actinomyces viscosus T14V and A. naeslundii WVU45 by human polymorphonuclear leukocytes in the absence of antibody or complement was mediated by the lectin associated with the type 2 fimbriae of these bacteria. This effect was markedly enhanced by exogenous sialidase, an enzyme also secreted by these actinomyces. Since sialidase treatment of the bacteria did not result in increa...

The pstSCAB-phoU operon encodes the phosphate-specific transport system (Pst). Loss of Pst constitutively activates the Pho regulon and decreases bacterial virulence. However, specific mechanisms underlying decreased bacterial virulence through inactivation of Pst are poorly understood. In uropathogenic Escherichia coli (UPEC) strain CFT073, inactivation of pst decreased urinary tract colonizat...

Salmonella enterica serovar Typhimurium produces two types of filamentous appendages on its surface. Fimbriae mediate adherence to tissues and cells via receptor-specific interactions, and flagella are the organelles of motility. These appendages play a role in colonization and dissemination, respectively, from infected surfaces and may be important components of bacterial survival. Increased e...

Although most Salmonella serovars are able to infect a range of animal hosts, some have acquired the ability to cause systemic infections of specific hosts. For example, Salmonella enterica serovar Choleraesuis is primarily associated with systemic infection in swine. Adherence to host epithelial cells is considered a prerequisite for initial infection, and fimbrial appendages on the outer memb...

CooD, the minor subunit of CS1 pili of enterotoxigenic Escherichia coli, is essential for the assembly of stable, functional pili. We previously proposed that CooD is a rate-limiting initiator of CS1 pilus assembly and predicted that the level of CooD expression should therefore determine the number of CS1 pili assembled on the cell surface. In this study, we confirm that CooD is required for t...

Type 4 fimbriae have been identified on the cell surface of Actinobacillus pleuropneumoniae by electron microscopy and N-terminal sequencing analysis. A. pleuropneumoniae type 4 fimbrial subunit protein, purified from cell cultures and from outer membrane preparations, reacted with polyclonal antibody raised against type 4 fimbriae of Moraxella bovis on Western blots. N-terminal sequence analys...