Killing of Caenorhabditis elegans by Burkholderia cepacia is controlled by the cep quorum-sensing system.
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.
Köthe
Manuela
M
Lehrstuhl für Mikrobiologie, Technische Universität München, Am Hochanger 4, 85350 Freising, Germany.
Antl
Melanie
M
Huber
Birgit
B
Stoecker
Kilian
K
Ebrecht
Doreen
D
Steinmetz
Ivo
I
Eberl
Leo
L
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
D001426:Bacterial Proteins; D029742:Caenorhabditis elegans Proteins; C117246:CepR protein, Burkholderia; C470991:phm-2 protein, C elegans