Comparative genomics of emerging human ehrlichiosis agents.
Anaplasma (formerly Ehrlichia) phagocytophilum, Ehrlichia chaffeensis, and Neorickettsia (formerly Ehrlichia) sennetsu are intracellular vector-borne pathogens that cause human ehrlichiosis, an emerging infectious disease. We present the complete genome sequences of these organisms along with comparisons to other organisms in the Rickettsiales order. Ehrlichia spp. and Anaplasma spp. display a unique large expansion of immunodominant outer membrane proteins facilitating antigenic variation. All Rickettsiales have a diminished ability to synthesize amino acids compared to their closest free-living relatives. Unlike members of the Rickettsiaceae family, these pathogenic Anaplasmataceae are capable of making all major vitamins, cofactors, and nucleotides, which could confer a beneficial role in the invertebrate vector or the vertebrate host. Further analysis identified proteins potentially involved in vacuole confinement of the Anaplasmataceae, a life cycle involving a hematophagous vector, vertebrate pathogenesis, human pathogenesis, and lack of transovarial transmission. These discoveries provide significant insights into the biology of these obligate intracellular pathogens.
The Institute for Genomic Research, Rockville, Maryland, USA. jdunning@tigr.org
Julie C
JC
Dunning Hotopp
Mingqun
M
Lin
Ramana
R
Madupu
Jonathan
J
Crabtree
Samuel V
SV
Angiuoli
Jonathan A
JA
Eisen
Jonathan
J
Eisen
Rekha
R
Seshadri
Qinghu
Q
Ren
Martin
M
Wu
Teresa R
TR
Utterback
Shannon
S
Smith
Matthew
M
Lewis
Hoda
H
Khouri
Chunbin
C
Zhang
Hua
H
Niu
Quan
Q
Lin
Norio
N
Ohashi
Ning
N
Zhi
William
W
Nelson
Lauren M
LM
Brinkac
Robert J
RJ
Dodson
M J
MJ
Rosovitz
Jaideep
J
Sundaram
Sean C
SC
Daugherty
Tanja
T
Davidsen
Anthony S
AS
Durkin
Michelle
M
Gwinn
Daniel H
DH
Haft
Jeremy D
JD
Selengut
Steven A
SA
Sullivan
Nikhat
N
Zafar
Liwei
L
Zhou
Faiza
F
Benahmed
Heather
H
Forberger
Rebecca
R
Halpin
Stephanie
S
Mulligan
Jeffrey
J
Robinson
Owen
O
White
Yasuko
Y
Rikihisa
Hervé
H
Tettelin
D000818:Animals; D001710:Biotin / Q000378:metabolism; D004260:DNA Repair; D004536:Ehrlichia / Q000235:genetics*; D016873:Ehrlichiosis / Q000235:genetics* / Q000382:microbiology; D016678:Genome; D023281:Genomics / Q000379:methods*; D006801:Humans; D008954:Models, Biological; D010802:Phylogeny; D012281:Rickettsia / Q000235:genetics; D013987:Ticks
D001710:Biotin