Comparative genome analysis of Salmonella Enteritidis PT4 and Salmonella Gallinarum 287/91 provides insights into evolutionary and host adaptation pathways.
We have determined the complete genome sequences of a host-promiscuous Salmonella enterica serovar Enteritidis PT4 isolate P125109 and a chicken-restricted Salmonella enterica serovar Gallinarum isolate 287/91. Genome comparisons between these and other Salmonella isolates indicate that S. Gallinarum 287/91 is a recently evolved descendent of S. Enteritidis. Significantly, the genome of S. Gallinarum has undergone extensive degradation through deletion and pseudogene formation. Comparison of the pseudogenes in S. Gallinarum with those identified previously in other host-adapted bacteria reveals the loss of many common functional traits and provides insights into possible mechanisms of host and tissue adaptation. We propose that experimental analysis in chickens and mice of S. Enteritidis-harboring mutations in functional homologs of the pseudogenes present in S. Gallinarum could provide an experimentally tractable route toward unraveling the genetic basis of host adaptation in S. enterica.
Thomson
Nicholas R
NR
The Pathogen Sequencing Unit, The Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, United Kingdom. nrt@sanger.ac.uk
Clayton
Debra J
DJ
Windhorst
Daniel
D
Vernikos
Georgios
G
Davidson
Susanne
S
Churcher
Carol
C
Quail
Michael A
MA
Stevens
Mark
M
Jones
Michael A
MA
Watson
Michael
M
Barron
Andy
A
Layton
Abigail
A
Pickard
Derek
D
Kingsley
Robert A
RA
Bignell
Alex
A
Clark
Louise
L
Harris
Barbara
B
Ormond
Doug
D
Abdellah
Zahra
Z
Brooks
Karen
K
Cherevach
Inna
I
Chillingworth
Tracey
T
Woodward
John
J
Norberczak
Halina
H
Lord
Angela
A
Arrowsmith
Claire
C
Jagels
Kay
K
Moule
Sharon
S
Mungall
Karen
K
Sanders
Mandy
M
Whitehead
Sally
S
Chabalgoity
Jose A
JA
Maskell
Duncan
D
Humphrey
Tom
T
Roberts
Mark
M
Barrow
Paul A
PA
Dougan
Gordon
G
Parkhill
Julian
J
D000222:Adaptation, Physiological / Q000235:genetics; D000818:Animals; D002645:Chickens / Q000382:microbiology; D019143:Evolution, Molecular; D016680:Genome, Bacterial; D051379:Mice; D008969:Molecular Sequence Data; D012475:Salmonella / Q000235:genetics*; D012481:Salmonella Infections, Animal / Q000235:genetics / Q000382:microbiology; D012477:Salmonella enteritidis / Q000235:genetics*