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.
Ogata
Hiroyuki
H
Structural and Genomic Information Laboratory, UPR 2589, IBSM, CNRS, Marseille Cedex, France. Hiroyuki.Ogata@igs.cnrs-mrs.fr
Renesto
Patricia
P
Audic
Stéphane
S
Robert
Catherine
C
Blanc
Guillaume
G
Fournier
Pierre-Edouard
PE
Parinello
Hugues
H
Claverie
Jean-Michel
JM
Raoult
Didier
D
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