title: Subinhibitory concentration of kanamycin induces the Pseudomonas aeruginosa type VI secretion system.
abstract: Pseudomonas aeruginosa is a Gram-negative bacterium found in natural environments including plants, soils and warm moist surfaces. This organism is also in the top ten of nosocomial pathogens, and prevalent in cystic fibrosis (CF) lung infections. The ability of P. aeruginosa to colonize a wide variety of environments in a lasting manner is associated with the formation of a resistant biofilm and the capacity to efficiently outcompete other microorganisms. Here we demonstrate that sub-inhibitory concentration of kanamycin not only induces biofilm formation but also induces expression of the type VI secretion genes in the H1-T6SS cluster. The H1-T6SS is known for its role in toxin production and bacterial competition. We show that the antibiotic induction of the H1-T6SS only occurs when a functional Gac/Rsm pathway is present. These observations may contribute to understand how P. aeruginosa responds to antibiotic producing competitors. It also suggests that improper antibiotic therapy may enhance P. aeruginosa colonization, including in the airways of CF patients.
authors.affiliation: MRC-Centre for Molecular Bacteriology and Infection (CBMI), Department of Life Sciences, Imperial College London, London, United Kingdom.
authors.forename: Cerith
authors.initials: C
authors.lastname: Jones
authors.forename: Luke
authors.initials: L
authors.lastname: Allsopp
authors.forename: Jack
authors.initials: J
authors.lastname: Horlick
authors.forename: Hemantha
authors.initials: H
authors.lastname: Kulasekara
authors.forename: Alain
authors.initials: A
authors.lastname: Filloux
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D058947:Bacterial Secretion Systems / Q000187:drug effects* / Q000235:genetics; D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development; D003470:Culture Media; D004305:Dose-Response Relationship, Drug; D015964:Gene Expression Regulation, Bacterial; D007612:Kanamycin / Q000494:pharmacology*; D010957:Plasmids; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development; D015398:Signal Transduction
chemical_list: D000900:Anti-Bacterial Agents; D058947:Bacterial Secretion Systems; D003470:Culture Media; D007612:Kanamycin