The genome sequence of Rickettsia felis identifies the first putative conjugative plasmid in an obligate intracellular parasite.
We sequenced the genome of Rickettsia felis, a flea-associated obligate intracellular alpha-proteobacterium causing spotted fever in humans. Besides a circular chromosome of 1,485,148 bp, R. felis exhibits the first putative conjugative plasmid identified among obligate intracellular bacteria. This plasmid is found in a short (39,263 bp) and a long (62,829 bp) form. R. felis contrasts with previously sequenced Rickettsia in terms of many other features, including a number of transposases, several chromosomal toxin-antitoxin genes, many more spoT genes, and a very large number of ankyrin- and tetratricopeptide-motif-containing genes. Host-invasion-related genes for patatin and RickA were found. Several phenotypes predicted from genome analysis were experimentally tested: conjugative pili and mating were observed, as well as beta-lactamase activity, actin-polymerization-driven mobility, and hemolytic properties. Our study demonstrates that complete genome sequencing is the fastest approach to reveal phenotypic characters of recently cultured obligate intracellular bacteria.
Structural and Genomic Information Laboratory, UPR 2589, IBSM, CNRS, Marseille Cedex, France. Hiroyuki.Ogata@igs.cnrs-mrs.fr
Hiroyuki
H
Ogata
Patricia
P
Renesto
Stéphane
S
Audic
Catherine
C
Robert
Guillaume
G
Blanc
Pierre-Edouard
PE
Fournier
Hugues
H
Parinello
Jean-Michel
JM
Claverie
Didier
D
Raoult
D000064:Acclimatization; D000954:Antigens, Surface / Q000032:analysis / Q000145:classification; D002874:Chromosome Mapping; D004269:DNA, Bacterial / Q000235:genetics; D005798:Genes, Bacterial; D016680:Genome, Bacterial; D023281:Genomics; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010641:Phenotype; D010957:Plasmids / Q000235:genetics* / Q000302:isolation & purification; D041161:Rickettsia felis / Q000235:genetics* / Q000472:pathogenicity / Q000648:ultrastructure; D012689:Sequence Homology, Nucleic Acid
D000954:Antigens, Surface; D004269:DNA, Bacterial