Genomic plasticity of the causative agent of melioidosis, Burkholderia pseudomallei.
Burkholderia pseudomallei is a recognized biothreat agent and the causative agent of melioidosis. This Gram-negative bacterium exists as a soil saprophyte in melioidosis-endemic areas of the world and accounts for 20% of community-acquired septicaemias in northeastern Thailand where half of those affected die. Here we report the complete genome of B. pseudomallei, which is composed of two chromosomes of 4.07 megabase pairs and 3.17 megabase pairs, showing significant functional partitioning of genes between them. The large chromosome encodes many of the core functions associated with central metabolism and cell growth, whereas the small chromosome carries more accessory functions associated with adaptation and survival in different niches. Genomic comparisons with closely and more distantly related bacteria revealed a greater level of gene order conservation and a greater number of orthologous genes on the large chromosome, suggesting that the two replicons have distinct evolutionary origins. A striking feature of the genome was the presence of 16 genomic islands (GIs) that together made up 6.1% of the genome. Further analysis revealed these islands to be variably present in a collection of invasive and soil isolates but entirely absent from the clonally related organism B. mallei. We propose that variable horizontal gene acquisition by B. pseudomallei is an important feature of recent genetic evolution and that this has resulted in a genetically diverse pathogenic species.
Holden
Matthew T G
MT
Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, United Kingdom.
Titball
Richard W
RW
Peacock
Sharon J
SJ
Cerdeño-Tárraga
Ana M
AM
Atkins
Timothy
T
Crossman
Lisa C
LC
Pitt
Tyrone
T
Churcher
Carol
C
Mungall
Karen
K
Bentley
Stephen D
SD
Sebaihia
Mohammed
M
Thomson
Nicholas R
NR
Bason
Nathalie
N
Beacham
Ifor R
IR
Brooks
Karen
K
Brown
Katherine A
KA
Brown
Nat F
NF
Challis
Greg L
GL
Cherevach
Inna
I
Chillingworth
Tracy
T
Cronin
Ann
A
Crossett
Ben
B
Davis
Paul
P
DeShazer
David
D
Feltwell
Theresa
T
Fraser
Audrey
A
Hance
Zahra
Z
Hauser
Heidi
H
Holroyd
Simon
S
Jagels
Kay
K
Keith
Karen E
KE
Maddison
Mark
M
Moule
Sharon
S
Price
Claire
C
Quail
Michael A
MA
Rabbinowitsch
Ester
E
Rutherford
Kim
K
Sanders
Mandy
M
Simmonds
Mark
M
Songsivilai
Sirirurg
S
Stevens
Kim
K
Tumapa
Sarinna
S
Vesaratchavest
Monkgol
M
Whitehead
Sally
S
Yeats
Corin
C
Barrell
Bart G
BG
Oyston
Petra C F
PC
Parkhill
Julian
J
D000328:Adult; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001482:Base Composition; D001483:Base Sequence; D016957:Burkholderia pseudomallei / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity; D002876:Chromosomes, Bacterial / Q000502:physiology; D004734:Energy Metabolism / Q000235:genetics; D019143:Evolution, Molecular; D005260:Female; D016680:Genome, Bacterial; D044404:Genomic Islands / Q000235:genetics; D006801:Humans; D008554:Melioidosis / Q000382:microbiology*; D008969:Molecular Sequence Data; D014774:Virulence
D001426:Bacterial Proteins