Polyadhesins: an armory of gram-negative Pathogens for Penetration through the immune shield (original) (raw)

The rapid emergence of treatment-resistant bacterial pathogens has become a major threat to public health. The recent outbreak of new Shiga-toxin–producing Escherichia coli o104H4 infection in Germany illustrates this problem. To colonize host tissues, pathogenic bacteria express surface adhesive organelles. The German strain uses aggregative adherence fimbriae I (aaF/I) to anchor to the intestinal mucosa and induce inflammation. aaF/I belong to the family of chaperone/usher assembled fimbrial polyadhesins. Polyadhesins are functioning as an armory for penetration through the host immune shield. The polyadhesin-binding to the target cells is orchestrated with injectisome (third secretion system), which is extremally important for bacterial virulency, and triggers subversive signals by aggregation of host cell receptors that al-low pathogens to mislead and evade immune defense. Polyadhesins also are involved in biofilm formation making bacteria more resistant to immune re-sponse. Bec...