title: Killing of Caenorhabditis elegans by Burkholderia cepacia is controlled by the cep quorum-sensing system.
abstract: Burkholderia cepacia H111, which was isolated from a cystic fibrosis patient, effectively kills the nematode Caenorhabditis elegans. Depending on the medium used for growth of the bacterium two different killing modes were observed. On high-osmolarity medium the nematodes became paralysed and died within 24 h. Using filter assays we provide evidence that this killing mode involves the production of an extracellular toxin. On nematode growth medium killing occurs over the course of 2-3 days and involves the accumulation of bacteria in the intestinal lumen of C. elegans. We demonstrate that the cep quorum-sensing system of H111 is required for efficient killing of C. elegans under both killing conditions. Using the C. elegans phm-2 mutant that has a non-functional grinder evidence is provided that the cep system is required to enter the intestinal lumen but is dispensable for the colonization of the gut. Furthermore, we demonstrate that the type II secretion machinery is not essential for nematode killing.
authors.affiliation: Lehrstuhl für Mikrobiologie, Technische Universität München, Am Hochanger 4, 85350 Freising, Germany.
authors.forename: Manuela
authors.initials: M
authors.lastname: Köthe
authors.forename: Melanie
authors.initials: M
authors.lastname: Antl
authors.forename: Birgit
authors.initials: B
authors.lastname: Huber
authors.forename: Kilian
authors.initials: K
authors.lastname: Stoecker
authors.forename: Doreen
authors.initials: D
authors.lastname: Ebrecht
authors.forename: Ivo
authors.initials: I
authors.lastname: Steinmetz
authors.forename: Leo
authors.initials: L
authors.lastname: Eberl
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000502:physiology; D016956:Burkholderia cepacia / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology; D017173:Caenorhabditis elegans / Q000235:genetics / Q000382:microbiology*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics; D005798:Genes, Bacterial; D017238:Genes, Helminth; D007422:Intestines / Q000382:microbiology; D009154:Mutation; D014774:Virulence / Q000235:genetics / Q000502:physiology
chemical_list: D001426:Bacterial Proteins; D029742:Caenorhabditis elegans Proteins; C117246:CepR protein, Burkholderia; C470991:phm-2 protein, C elegans