We studied the role of two members of the 100-kDa heat shock protein family, the ClpC and ClpE ATPases, in cell adhesion and invasion of the intracellular pathogen Listeria monocytogenes. During the early phase of infection, a clpC mutant failed to disseminate to hepatocytes in the livers of infected mice whereas the invasive capacity of a clpE mutant remained unchanged. This was confirmed by a...

During colonization of the respiratory tract by Bordetella pertussis, virulence factors contribute to adherence of the bacterium to the respiratory tract epithelium. In the present study, we examined the roles of the virulence factors filamentous hemagglutinin (FHA), fimbriae, pertactin (Prn), and pertussis toxin (PT) in the adherence of B. pertussis to cells of the human bronchial epithelial c...

Adhesins facilitate bacterial colonization and invasion of host tissues are considered virulence factors, but their impact on immune-mediated damage as a driver pathogenesis remains unclear. Yersinia pseudotuberculosis encodes for multivalent adhesion molecule (MAM), mammalian cell entry (MCE) family protein adhesin. MAMs widespread in Gram-negative bacteria enable enteric to colonize epithelia...

Edwardsiella tarda is a Gram-negative bacterium that causes a systemic infection, edwardsiellosis, in fish. The virulence factors of this pathogen and its genetic determinants have not been systematically examined. In this study, TnphoA transposon mutagenesis was used to construct a library of 440 alkaline phosphatase (PhoA(+)) fusion mutants from a total of 400000 transconjugants derived from ...

Streptococcus sanguinis is the most common cause of infective endocarditis (IE). Since the molecular basis of virulence of this oral commensal bacterium remains unclear, we searched the genome of S. sanguinis for previously unidentified virulence factors. We identified a cell surface ecto-5'-nucleotidase (Nt5e), as a candidate virulence factor. By colorimetric phosphate assay, we showed that S....

The ability of Escherichia coli to colonize both intestinal and extraintestinal sites is driven by the presence of specific virulence factors, among which are the autotransporter (AT) proteins. Members of the trimeric AT adhesin family are important virulence factors for several gram-negative pathogens and mediate adherence to eukaryotic cells and extracellular matrix (ECM) proteins. In this st...

pasteurella multocida is an opportunistic pathogen responsible for pneumonia of lambs and goats, respiratory atrophic rhinitis of swine. although the molecular basis of the pathogenicity and host specificity of p. multocida is not well understood, several studies have reported that a number of proteins are correlated with the pathogenic mechanisms. adhesins have a crucial role in mediating colo...

Porphyromonas gingivalis has been implicated as a key etiologic agent in the pathogenesis of destructive chronic periodontitis. Among virulence factors of this organism are cysteine proteinases, or gingipains, that have the capacity to modulate host inflammatory defenses. Intercellular adhesion molecule expression by vascular endothelium represents a crucial process for leukocyte transendotheli...

Plasmodium falciparum virulence is linked to its ability to sequester in post-capillary venules in the human host. Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) is the main variant surface antigen implicated in this process. Complete loss of parasite adhesion is linked to a large subtelomeric deletion on chromosome 9 in a number of laboratory strains such as D10 and T9-96. Simil...

BACKGROUND & OBJECTIVES The complex interactions that occur between host and pathogen during bacteraemia caused by Streptococcus pneumoniae are not well understood. Upon entering the blood stream the pneumococcus intiates responses through contact with naïve monocytes and macrophages resulting in an inflammatory response. To elucidate the role of microbial virulence factors in the host response...