Detalle de: Quorum Sensing in Acinetobacter Virulence

The genus Acinetobacter includes non-pathogenic species inhabitants of the human skin, intestinal tract, and respiratory system, but several species belonging to the A. calcoaceticus-A. baumannii or ACB complex cause severe nosocomial infections, mostly in immunocompromised patients. Among these, A. baumannii is of special relevance due to its high ability to acquire multidrug resistance genes and its formidable surviving capacity as biofilm former. Due to the limited effective treatment options, A. baumannii is considered one of the most dangerous human pathogens worldwide; therefore, a more thorough understanding of its virulence control mechanisms is essential for the development of new anti-pathogenic strategies against this pathogen. The control of biofilm formation, and other traits related to virulence, is multifactorial, involving several regulatory networks and including the cell density-dependent communication system known as quorum sensing (QS). Acinetobacter presents a typical LuxIR-type QS network involving the acyl homoserine lactone signal synthase AbaI and receptor AbaR, as well as several quorum quenching enzymes. Earlier reports have described the involvement of QS in virulence, and attempts to control Acinetobacter pathogenesis through QS inhibition have shown different degrees of success. In this chapter, we will review the role of QS in Acinetobacter virulence and the up-to-date approaches to utilise Acinetobacter QS circuits as therapeutic targets.