title: A functional phenylacetic acid catabolic pathway is required for full pathogenicity of Burkholderia cenocepacia in the Caenorhabditis elegans host model.
abstract: Burkholderia cenocepacia is a member of the Burkholderia cepacia complex, a group of metabolically versatile bacteria that have emerged as opportunistic pathogens in cystic fibrosis and immunocompromised patients. Previously a screen of transposon mutants in a rat pulmonary infection model identified an attenuated mutant with an insertion in paaE, a gene related to the phenylacetic acid (PA) catabolic pathway. In this study, we characterized gene clusters involved in the PA degradation pathway of B. cenocepacia K56-2 in relation to its pathogenicity in the Caenorhabditis elegans model of infection. We demonstrated that targeted-insertion mutagenesis of paaA and paaE, which encode part of the putative PA-coenzyme A (CoA) ring hydroxylation system, paaZ, coding for a putative ring opening enzyme, and paaF, encoding part of the putative beta-oxidation system, severely reduces growth on PA as a sole carbon source. paaA and paaE insertional mutants were attenuated for virulence, and expression of paaE in trans restored pathogenicity of the paaE mutant to wild-type levels. Interruption of paaZ and paaF slightly increased virulence. Using gene interference by ingested double-stranded RNA, we showed that the attenuated phenotype of the paaA and paaE mutants is dependent on a functional p38 mitogen-activated protein kinase pathway in C. elegans. Taken together, our results demonstrate that B. cenocepacia possesses a functional PA degradation pathway and that the putative PA-CoA ring hydroxylation system is required for full pathogenicity in C. elegans.
authors.affiliation: Department of Microbiology, Buller Building, Room 418, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2.
authors.forename: Robyn J
authors.initials: RJ
authors.lastname: Law
authors.forename: Jason N R
authors.initials: JN
authors.lastname: Hamlin
authors.forename: Aida
authors.initials: A
authors.lastname: Sivro
authors.forename: Stuart J
authors.initials: SJ
authors.lastname: McCorrister
authors.forename: Georgina A
authors.initials: GA
authors.lastname: Cardama
authors.forename: Silvia T
authors.initials: ST
authors.lastname: Cardona
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D016956:Burkholderia cepacia / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity; D017173:Caenorhabditis elegans / Q000382:microbiology*; D015964:Gene Expression Regulation, Bacterial; D054884:Host-Pathogen Interactions; D007422:Intestines / Q000382:microbiology; D008957:Models, Genetic; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics; D016254:Mutagenesis, Insertional; D010648:Phenylacetates / Q000378:metabolism*; D014774:Virulence / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D010648:Phenylacetates; C025136:phenylacetic acid
references.citation: Environ Microbiol. 2008 Jun;10(6):1652-60
references.pmid: 18341581
references.citation: J Soc Biol. 2003;197(4):375-8
references.pmid: 15005519
references.citation: Cell Microbiol. 2003 May;5(5):343-51
references.pmid: 12713492
references.citation: Appl Environ Microbiol. 2006 Nov;72(11):7422-6
references.pmid: 16997993
references.citation: Proc Natl Acad Sci U S A. 2006 Jul 5;103(27):10414-10419
references.pmid: 16801562
references.citation: Proc Natl Acad Sci U S A. 2000 Jun 6;97(12):6640-5
references.pmid: 10829079
references.citation: Plasmid. 2005 Nov;54(3):219-28
references.pmid: 15925406
references.citation: J Gen Microbiol. 1989 Nov;135(11):2885-90
references.pmid: 2693589
references.citation: Nucleic Acids Res. 2000 Jan 1;28(1):33-6
references.pmid: 10592175
references.citation: Bioinformatics. 2000 Oct;16(10):944-5
references.pmid: 11120685
references.citation: Trends Microbiol. 2005 Mar;13(3):119-27
references.pmid: 15737730
references.citation: J Clin Microbiol. 2000 Feb;38(2):910-3
references.pmid: 10655415
references.citation: PLoS One. 2006 Dec 20;1:e77
references.pmid: 17183709
references.citation: Environ Microbiol. 2002 Dec;4(12):824-41
references.pmid: 12534466
references.citation: Proc Natl Acad Sci U S A. 2001 Sep 11;98(19):10892-7
references.pmid: 11535834
references.citation: Arch Microbiol. 2002 Sep;178(3):180-92
references.pmid: 12189419
references.citation: Nature. 1998 Oct 29;395(6705):854
references.pmid: 9804418
references.citation: Eur J Biochem. 2003 Jul;270(14):3047-54
references.pmid: 12846838
references.citation: Proteomics. 2006 Feb;6(4):1301-18
references.pmid: 16470664
references.citation: Int Immunopharmacol. 2007 Jan;7(1):70-7
references.pmid: 17161819
references.citation: Microbiol Mol Biol Rev. 2001 Dec;65(4):523-69, table of contents
references.pmid: 11729263
references.citation: Nature. 2000 Nov 16;408(6810):325-30
references.pmid: 11099033
references.citation: Infect Immun. 2004 Jul;72(7):4010-22
references.pmid: 15213146
references.citation: Infect Immun. 2008 Jan;76(1):38-47
references.pmid: 17967860
references.citation: Mol Microbiol. 2001 Mar;39(6):1434-42
references.pmid: 11260461
references.citation: Clin Cancer Res. 2000 Mar;6(3):933-41
references.pmid: 10741718
references.citation: J Environ Monit. 2002 Apr;4(2):270-5
references.pmid: 11993768
references.citation: Appl Environ Microbiol. 2002 Dec;68(12):5956-64
references.pmid: 12450816
references.citation: Proc Natl Acad Sci U S A. 1979 Apr;76(4):1648-52
references.pmid: 377280
references.citation: PLoS Pathog. 2007 Apr;3(4):e57
references.pmid: 17447841
references.citation: Nat Rev Microbiol. 2005 Feb;3(2):144-56
references.pmid: 15643431
references.citation: Appl Environ Microbiol. 2008 Feb;74(4):1064-75
references.pmid: 18156318
references.citation: J Biol Chem. 1998 Oct 2;273(40):25974-86
references.pmid: 9748275
references.citation: J Bacteriol. 1994 Nov;176(21):6479-88
references.pmid: 7961399
references.citation: J Exp Zool. 1990 Mar;253(3):263-70
references.pmid: 2181052
references.citation: Infect Immun. 2006 Oct;74(10):5477-86
references.pmid: 16988222
references.citation: FEMS Microbiol Lett. 2005 Sep 1;250(1):97-104
references.pmid: 16043310
references.citation: Proc Natl Acad Sci U S A. 1998 May 26;95(11):6419-24
references.pmid: 9600981
references.citation: Lett Appl Microbiol. 2004;38(3):181-4
references.pmid: 14962037
references.citation: Science. 2002 Jul 26;297(5581):623-6
references.pmid: 12142542
references.citation: J Bacteriol. 2005 Jul;187(13):4497-504
references.pmid: 15968060
references.citation: J Bacteriol. 1988 Jun;170(6):2575-83
references.pmid: 2836362
references.citation: Proc Natl Acad Sci U S A. 1972 Aug;69(8):2110-4
references.pmid: 4559594
references.citation: J Bacteriol. 1985 Nov;164(2):918-21
references.pmid: 2997137
references.citation: Proc Natl Acad Sci U S A. 2006 Sep 19;103(38):14086-91
references.pmid: 16968778
references.citation: J Clin Invest. 1997 Dec 1;100(11):2671-9
references.pmid: 9389730
references.citation: Infect Immun. 2007 Apr;75(4):1679-89
references.pmid: 17220310
references.citation: Curr Opin Microbiol. 2002 Feb;5(1):97-101
references.pmid: 11834377
references.citation: Infect Immun. 2008 Mar;76(3):1059-67
references.pmid: 18195023
references.citation: Curr Opin Microbiol. 2005 Feb;8(1):99-105
references.pmid: 15694863
references.citation: Infect Immun. 1998 Feb;66(2):874-7
references.pmid: 9453660
references.citation: Microbiology (Reading). 2007 Feb;153(Pt 2):357-365
references.pmid: 17259607
references.citation: Oecologia. 1984 Oct;64(2):163-167
references.pmid: 28312333