title: Lipopolysaccharide modification in Gram-negative bacteria during chronic infection.
abstract: The Gram-negative bacterial lipopolysaccharide (LPS) is a major component of the outer membrane that plays a key role in host-pathogen interactions with the innate immune system. During infection, bacteria are exposed to a host environment that is typically dominated by inflammatory cells and soluble factors, including antibiotics, which provide cues about regulation of gene expression. Bacterial adaptive changes including modulation of LPS synthesis and structure are a conserved theme in infections, irrespective of the type or bacteria or the site of infection. In general, these changes result in immune system evasion, persisting inflammation and increased antimicrobial resistance. Here, we review the modifications of LPS structure and biosynthetic pathways that occur upon adaptation of model opportunistic pathogens (Pseudomonas aeruginosa, Burkholderia cepacia complex bacteria, Helicobacter pylori and Salmonella enterica) to chronic infection in respiratory and gastrointestinal sites. We also discuss the molecular mechanisms of these variations and their role in the host-pathogen interaction.
authors.affiliation: Institute for Bioengineering and Biosciences, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal.
authors.forename: Rita F
authors.initials: RF
authors.lastname: Maldonado
authors.affiliation: Institute for Bioengineering and Biosciences, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal.
authors.forename: Isabel
authors.initials: I
authors.lastname: Sá-Correia
authors.affiliation: Department of Microbiology and Immunology, University of Western Ontario, London, ON, Canada.|Centre for Infection and Immunity, Queen's University Belfast, Belfast, UK
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Valvano
mesh_terms: D002908:Chronic Disease; D005767:Gastrointestinal Diseases / Q000276:immunology / Q000382:microbiology*; D006090:Gram-Negative Bacteria / Q000502:physiology; D016905:Gram-Negative Bacterial Infections / Q000276:immunology / Q000378:metabolism* / Q000382:microbiology*; D054884:Host-Pathogen Interactions / Q000276:immunology*; D006801:Humans; D008070:Lipopolysaccharides / Q000096:biosynthesis / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D012141:Respiratory Tract Infections / Q000276:immunology / Q000382:microbiology*
chemical_list: D008070:Lipopolysaccharides
keywords: Burkholderia cenocepacia; Helicobacter pylori; O antigen; Pseudomonas aeruginosa; adaptive mutation; cystic fibrosis; gastric ulcer; lipid A