Characterization of the type III capsular polysaccharide produced by Burkholderia pseudomallei.
Burkholderia pseudomallei has been shown to produce more than one capsular polysaccharide (CPS). Analysis of the B. pseudomallei genome has revealed that the organism contains four CPS operons (I-IV). One of these operons (CPS III) was selected for further study. Comparative sequencing analysis revealed that the genes encoding CPS III are present in B. pseudomallei and Burkholderia thailandensis but not in Burkholderia mallei. In this study, CPS III was not found to contribute to the virulence of B. pseudomallei. Strains containing mutations in CPS III had the same LD(50) value as the wild-type when tested in an animal infection model. Production of CPS III was shown to be induced in water but inhibited in 30% normal human serum using a lux reporter fusion assay. Microarray analysis of capsule gene expression in infected hamsters revealed that the genes encoding CPS III were not significantly expressed in vivo compared with the genes encoding the previously characterized mannoheptose capsule (CPS I), which is an important virulence factor in B. pseudomallei. Glycosyl-composition analysis by combined GC/MS indicated that the CPS III genes are involved in the synthesis of a capsule composed of galactose, glucose, mannose and xylose.
Reckseidler-Zenteno
Shauna L
SL
Centre for Science, Athabasca University, Athabasca, AB T9S 9Z9, Canada.|Department of Microbiology and Infectious Diseases, University of Calgary Health Sciences Center, Calgary, AB T2N 4N1, Canada.
Viteri
Duber-Frey
DF
Department of Microbiology and Infectious Diseases, University of Calgary Health Sciences Center, Calgary, AB T2N 4N1, Canada.
Moore
Richard
R
Department of Microbiology and Infectious Diseases, University of Calgary Health Sciences Center, Calgary, AB T2N 4N1, Canada.
Wong
Erica
E
Department of Microbiology and Infectious Diseases, University of Calgary Health Sciences Center, Calgary, AB T2N 4N1, Canada.
Tuanyok
Apichai
A
Department of Microbiology and Infectious Diseases, University of Calgary Health Sciences Center, Calgary, AB T2N 4N1, Canada.
Woods
Donald E
DE
Department of Microbiology and Infectious Diseases, University of Calgary Health Sciences Center, Calgary, AB T2N 4N1, Canada.
D000818:Animals; D016667:Bacterial Capsules / Q000235:genetics / Q000378:metabolism*; D016957:Burkholderia pseudomallei / Q000378:metabolism* / Q000472:pathogenicity; D006224:Cricetinae; D005260:Female; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D008554:Melioidosis / Q000382:microbiology; D008647:Mesocricetus; D046228:Microarray Analysis; D009154:Mutation; D014774:Virulence