Project description:An Aeromonas allosaccharophila environmental isolate recovered from the Seine River (Paris, France) produced a novel extended-spectrum beta-lactamase, PER-6, that shared 92% amino acid identity with the closest ss-lactamase, PER-2. The kinetic properties of PER-6 showed a slightly increased affinity for carbapenems. The bla(PER-6) gene was chromosomally located and bracketed by non-transposon-related structures.
Project description:Aeromonas caviae has been associated with human gastrointestinal disease. Strains of this species typically lack virulence factors (VFs) such as enterotoxins and hemolysins that are produced by other human pathogens of the Aeromonas genus. Microarray profiling of murine small intestinal extracts, 24 hours after oral infection with an A. caviae strain, provides evidence of a Th1 type immune response. A large number of gamma-interferon (γ-IFN) induced genes are up-regulated as well as several tumor necrosis factor-alpha (TNF-α) transcripts. A. caviae has always been considered an opportunistic pathogen because it lacks obvious virulence factors. This current effort suggests A. caviae colonizes murine intestinal tract and causes what has been described by others as a dysregulatory cytokine response leading to an irritable bowel-like syndrome. This response would explain why a number of diarrheal waterborne outbreaks have been attributed to A. caviae even though it lacks obvious enteropathogenic properties. Keywords: Aeromonas caviae, infection, disease mechanism, TH1 resposne
