March 5 - 6, 2009. Ecology of Pathogenic Escherichia coli
Oslo, Norway Further information
Pathogenic Escherichia coli Network International Conference. The conference aims to increase understanding of the role of the environment and environmental factors in the survival, persistence and transmission of pathogenic Escherichia coli. Topics to be covered include: Gut Ecology, Phages, Survival and persistence, Stress response and adaption.

September 17 - 18, 2009. Control and Management of Pathogenic Escherichia coli
Dublin, Ireland Further information
Pathogenic Escherichia coli Network International Conference.

Labels: conference, Escherichia coli, pathogen, pathogenic

Bacteria assemble a variety of structures on their cell surface, including extended fibers generally termed pili or fimbriae. These pili mediate interactions with other bacteria, the host, and the environment.

Pili often function as adhesins, dictating specific binding to and colonization of biological as well as non-biological surfaces. Pili are critical virulence factors for pathogenic bacteria, initiating infection and determining how and where bacterial colonization may occur. A variety of different classes of pili are found in prokaryotes. Pili have a diverse array of functions. Pili are essential for host colonization, virulence and pathogenesis for many bacteria and, in the case of type IV pili, can also be employed for motility across solid surfaces.

Further reading:

1. Pili and Flagella
2. Bacterial Secreted Proteins
3. Microbiology Books

Labels: adhesins, colonization, fimbriae, flagella, motility, pathogenesis, pathogenic, pili, type IV pili, virulence

Protein secretion is an important process for bacteria and is particularly important to bacterial pathogens. Secreted proteins have a range of biological functions.

The majority of proteins destined for export across the microbial cytoplasmic membrane or integration into the membrane are handled by the evolutionarily conserved Sec system. The Sec substrates have specific topogenic signals and are targeted to the membrane-embedded SecYEG translocon that serves as a polypeptide-conducting channel either co-translationally by SRP for lipid-phase integration or post-translationally by SecB for complete translocation. The plug helix of SecY that clogs the unused channel and the central constriction that seals around the translocating chain make the translocon function compatible with the permeability barrier of the membrane. The translocon also contains a lateral gate, through which it not only accepts a newly synthesized client protein but also allows its hydrophobic segment, if any, to partition into the lipid phase. The post-translational mode of translocation, characteristic of the bacterial systems, is driven by the SecA ATPase, which interacts with SecY and a preprotein and accordingly undergoes conformational transitions coupled with the ATPase cycles.

from Ito and Mori in Bacterial Secreted Proteins

Further reading: Bacterial Secreted Proteins: Secretory Mechanisms and Role in Pathogenesis

Labels: pathogen, pathogenic, protein, protein secretion, proteins