title: Serratia marcescens is able to survive and proliferate in autophagic-like vacuoles inside non-phagocytic cells.
abstract: Serratia marcescens is an opportunistic human pathogen that represents 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. In this work, we explore the invasion process of this opportunistic pathogen to epithelial cells. We demonstrate that once internalized, Serratia is able not only to persist but also to multiply inside a large membrane-bound compartment. This structure displays autophagic-like features, acquiring LC3 and Rab7, markers described to be recruited throughout the progression of antibacterial autophagy. The majority of the autophagic-like vacuoles in which Serratia resides and proliferates are non-acidic and have no degradative properties, indicating that the bacteria are capable to either delay or prevent fusion with lysosomal compartments, altering the expected progression of autophagosome maturation. In addition, our results demonstrate that Serratia triggers a non-canonical autophagic process before internalization. These findings reveal that S. marcescens is able to manipulate the autophagic traffic, generating a suitable niche for survival and proliferation inside the host cell.
authors: Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Departamento de Microbiología, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina.
authors: Griselda V
authors: GV
authors: Fedrigo
authors: Emanuel M
authors: EM
authors: Campoy
authors: Gisela
authors: G
authors: Di Venanzio
authors: María Isabel
authors: MI
authors: Colombo
authors: Eleonora
authors: E
authors: García Véscovi
mesh_terms: D000643:Ammonium Chloride / Q000494:pharmacology; D000730:Androstadienes / Q000494:pharmacology; D000818:Animals; D001343:Autophagy; D016466:CHO Cells; D002460:Cell Line; D006224:Cricetinae; D004847:Epithelial Cells / Q000382:microbiology; D019084:Fluorescent Antibody Technique, Indirect; D005839:Gentamicins / Q000494:pharmacology; D006801:Humans; D018942:Macrolides / Q000494:pharmacology; D018613:Microscopy, Confocal; D012706:Serratia marcescens / Q000187:drug effects / Q000502:physiology*; D014617:Vacuoles / Q000382:microbiology*; D000077191:Wortmannin
chemical_list: D000730:Androstadienes; D005839:Gentamicins; D018942:Macrolides; D000643:Ammonium Chloride; C040929:bafilomycin A1; D000077191:Wortmannin