Gene regulation and virulence strategies of the opportunistic pathogen Serratia marcescens

ELEONORA GARCIA VESCOVI

Puerto Varas

Conferencia; XII PABMB Congress; 2013

PABMB

Conference: Serratia marcescens is a wide host range enterobacterium that can be isolated from plants, insects and nematodes, also being an opportunistic pathogen of mammals. In recent years, S. marcescens has become a growing problem for public health, particularly in hospitalized or immunocompromised patients. However, little is known about factors and mechanisms that contribute to S. marcescens pathogenesis within its host. We demonstrate that once internalized in non-professional phagocytic cells, Serratia is able not only to persist but also to multiply inside a large membrane-bound compartment with autophagic-like features. Our findings reveal that this pathogen maneuvers the canonical progression of autophagosome maturation, altering the vesicular traffic in order to tailor a suitable niche for survival and proliferation within the host cell. This ability of bacteria to interact, colonize and invade live hosts or abiotic niches relies on their capacity to cope with life-threatening conditions posed by the environment. Two-component systems are one of the most ubiquitous signal transduction mechanisms by which bacteria generate adaptive responses to environmental challenges. We will discuss our recent findings, disclosing the role of the PhoP/PhoQ and RcsCDB systems as master regulators of the expression of determinants required for the interaction of Serratia with the host.