Differential expression of Haemophilus parasuis genes in response to iron restriction and cerebrospinal fluid.
Haemophilus parasuis is an important opportunistic pathogen in swine of high health status, but to date no proven virulence factors have been described. As virulence factors are known to be regulated during disease, the objective of this study was to identify genes of a virulent serovar 5 strain with altered expression after iron restriction or in the presence of porcine cerebrospinal fluid (CSF), conditions that reflect in vivo growth conditions. Using differential-display reverse-transcriptase-mediated polymerase chain reaction, we found that homologues of genes encoding fructose bisphosphate aldolase (fba), adenylosuccinate synthetase (purA), 2',3'-cyclic nucleotide phosphodiesterase (cpdB), lipoprotein signal peptidase (lspA), pyrophosphate reductase (lytB), superoxide dismutase (sodC), tyrosyl t-RNA synthetase (tyrS), cysteine synthetase (cysK), an unknown protein, and a homologue of a hydrolase of the haloacid dehydrogenase superfamily were upregulated in response to iron restriction. In addition, the purA, cpdB, lspA, lytB, and sodC homologues, cDNAs homologous with a Na+/alanine symporter, fatty acid ligase (fadD), diadenosine tetraphosphatase (apaH), and an unknown protein were upregulated in response to CSF. In screening for the presence of these differentially expressed genes to assess their usefulness as diagnostic markers of high virulence potential, we detected homologues of all of these genes in all of the reference strains of the 15 established serovars. The hydrolase homologue, however, was expressed only in representative H. parasuis strains associated with a high virulence potential, suggesting that this enzyme may play a role in pathogenesis.
Metcalf
Devon S
DS
Department of Pathobiology, University of Guelph, Guelph, Ontario.
MacInnes
Janet I
JI
D000818:Animals; D001483:Base Sequence; D015415:Biomarkers / Q000032:analysis; D002555:Cerebrospinal Fluid / Q000382:microbiology; D015964:Gene Expression Regulation, Bacterial; D006192:Haemophilus Infections / Q000382:microbiology / Q000662:veterinary*; D044137:Haemophilus parasuis / Q000201:enzymology / Q000235:genetics* / Q000472:pathogenicity; D007501:Iron / Q000378:metabolism; D000090463:Iron Deficiencies; D012329:RNA, Bacterial; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013552:Swine; D013553:Swine Diseases / Q000382:microbiology*; D015854:Up-Regulation; D037521:Virulence Factors / Q000235:genetics
D015415:Biomarkers; D012329:RNA, Bacterial; D037521:Virulence Factors; D007501:Iron
Microbiology. 2001 Jan;147(Pt 1):203-13
11160814
Vet Microbiol. 2005 Dec 20;111(3-4):231-6
16271834
Infect Immun. 2002 Nov;70(11):6032-42
12379679
Vet Microbiol. 2003 May 2;93(1):79-87
12591209
Am J Vet Res. 2003 Apr;64(4):435-42
12693533
Can J Vet Res. 2003 Jul;67(3):229-31
12889731
Vet Microbiol. 2003 Oct 17;96(2):189-202
14519336
Arch Microbiol. 2003 Oct;180(4):240-50
12904831
J Clin Microbiol. 2004 Feb;42(2):839-40
14766867
Can J Vet Res. 2004 Jan;68(1):71-5
14979439
Mol Microbiol. 1989 Aug;3(8):1083-9
2532702
Mol Gen Genet. 1990 Jun;222(1):161-5
2172762
J Bacteriol. 1991 Aug;173(15):4653-9
1856166
J Clin Microbiol. 1992 Apr;30(4):862-5
1572971
Zentralbl Veterinarmed B. 1992 Feb;39(1):59-64
1349784
J Vet Med Sci. 1994 Aug;56(4):639-44
7999883
Can J Microbiol. 1995 Jan;41(1):70-4
7728656
Methods Enzymol. 1999;303:309-24
10349652
J Biol Chem. 2004 Dec 24;279(52):54687-94
15489502
Vet Microbiol. 2005 Feb 25;105(3-4):223-8
15708819
Vet Microbiol. 2005 Mar 20;106(1-2):145-51
15737484
Vet Microbiol. 2005 Oct 31;110(3-4):255-63
16144750
J Bacteriol. 2005 Nov;187(22):7561-8
16267280
J Vet Med Sci. 2001 May;63(5):487-91
11411491