Genome analysis of multiple pathogenic isolates of Streptococcus agalactiae: implications for the microbial "pan-genome".
The development of efficient and inexpensive genome sequencing methods has revolutionized the study of human bacterial pathogens and improved vaccine design. Unfortunately, the sequence of a single genome does not reflect how genetic variability drives pathogenesis within a bacterial species and also limits genome-wide screens for vaccine candidates or for antimicrobial targets. We have generated the genomic sequence of six strains representing the five major disease-causing serotypes of Streptococcus agalactiae, the main cause of neonatal infection in humans. Analysis of these genomes and those available in databases showed that the S. agalactiae species can be described by a pan-genome consisting of a core genome shared by all isolates, accounting for approximately 80% of any single genome, plus a dispensable genome consisting of partially shared and strain-specific genes. Mathematical extrapolation of the data suggests that the gene reservoir available for inclusion in the S. agalactiae pan-genome is vast and that unique genes will continue to be identified even after sequencing hundreds of genomes.
Tettelin
Hervé
H
Institute for Genomic Research, 9712 Medical Center Drive, Rockville, MD 20850, USA.
Masignani
Vega
V
Cieslewicz
Michael J
MJ
Donati
Claudio
C
Medini
Duccio
D
Ward
Naomi L
NL
Angiuoli
Samuel V
SV
Crabtree
Jonathan
J
Jones
Amanda L
AL
Durkin
A Scott
AS
Deboy
Robert T
RT
Davidsen
Tanja M
TM
Mora
Marirosa
M
Scarselli
Maria
M
Margarit y Ros
Immaculada
I
Peterson
Jeremy D
JD
Hauser
Christopher R
CR
Sundaram
Jaideep P
JP
Nelson
William C
WC
Madupu
Ramana
R
Brinkac
Lauren M
LM
Dodson
Robert J
RJ
Rosovitz
Mary J
MJ
Sullivan
Steven A
SA
Daugherty
Sean C
SC
Haft
Daniel H
DH
Selengut
Jeremy
J
Gwinn
Michelle L
ML
Zhou
Liwei
L
Zafar
Nikhat
N
Khouri
Hoda
H
Radune
Diana
D
Dimitrov
George
G
Watkins
Kisha
K
O'Connor
Kevin J B
KJ
Smith
Shannon
S
Utterback
Teresa R
TR
White
Owen
O
Rubens
Craig E
CE
Grandi
Guido
G
Madoff
Lawrence C
LC
Kasper
Dennis L
DL
Telford
John L
JL
Wessels
Michael R
MR
Rappuoli
Rino
R
Fraser
Claire M
CM
D000595:Amino Acid Sequence; D016667:Bacterial Capsules / Q000235:genetics; D001483:Base Sequence; D015870:Gene Expression; D005798:Genes, Bacterial; D014644:Genetic Variation; D016680:Genome, Bacterial; D008969:Molecular Sequence Data; D010802:Phylogeny; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013292:Streptococcus agalactiae / Q000145:classification* / Q000235:genetics* / Q000472:pathogenicity; D014774:Virulence / Q000235:genetics