Notably, bacterial biofilm formation is increasingly recognized as a passive virulence factor facilitating many infectious disease processes. In this review we will focus on bacterial biofilms formed by human pathogens and highlight their relevance for diverse diseases. Along biofilm composition and regulation emphasis is laid on the intensively studied biofilms of Vibrio cholerae, Pseudomonas aeruginosa and Staphylococcus spp., which are commonly used as biofilm model organisms and therefore contribute to our general understanding of bacterial biofilm (patho-)physiology. Finally, therapeutical intervention strategies targeting biofilms will be discussed.

SMAD proteins mediate TGF-β signaling and thereby regulate the metazoan development; however, they are poorly defined in Haemonchus contortus–a common blood-sucking parasitic nematode of small ruminants. Here, we characterized an R-SMAD family protein in H. contortus termed HcSMA2, which is closely related to Caenorhabditis elegans SMA2 (CeSMA2) involved in the bone morphogenetic protein (BMP) signaling. Hcsma2 is transcribed in all developmental stages of H. contortus but highly induced in the adult male worms. The RNA interference with Hcsma2 retarded the transition of infective L3 into L4 larvae. Besides, the bimolecular fluorescence complementation revealed the interaction of HcSMA2 with a TGF-β-activated-R-SMAD (HcDAF8). Together these results show a BMP-like receptor-regulated SMAD in H. contortus that is required for larval differentiation and underscore an adaptive functional repurposing of BMP-signaling in parasitic worms.