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.
Dunning Hotopp
Julie C
JC
The Institute for Genomic Research, Rockville, Maryland, USA. jdunning@tigr.org
Lin
Mingqun
M
Madupu
Ramana
R
Crabtree
Jonathan
J
Angiuoli
Samuel V
SV
Eisen
Jonathan A
JA
Eisen
Jonathan
J
Seshadri
Rekha
R
Ren
Qinghu
Q
Wu
Martin
M
Utterback
Teresa R
TR
Smith
Shannon
S
Lewis
Matthew
M
Khouri
Hoda
H
Zhang
Chunbin
C
Niu
Hua
H
Lin
Quan
Q
Ohashi
Norio
N
Zhi
Ning
N
Nelson
William
W
Brinkac
Lauren M
LM
Dodson
Robert J
RJ
Rosovitz
M J
MJ
Sundaram
Jaideep
J
Daugherty
Sean C
SC
Davidsen
Tanja
T
Durkin
Anthony S
AS
Gwinn
Michelle
M
Haft
Daniel H
DH
Selengut
Jeremy D
JD
Sullivan
Steven A
SA
Zafar
Nikhat
N
Zhou
Liwei
L
Benahmed
Faiza
F
Forberger
Heather
H
Halpin
Rebecca
R
Mulligan
Stephanie
S
Robinson
Jeffrey
J
White
Owen
O
Rikihisa
Yasuko
Y
Tettelin
Hervé
H
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