title: Experimental infection models of ticks of the Rhipicephalus sanguineus group with Rickettsia conorii.
abstract: Rhipicephalus sanguineus group ticks collected on dogs in Thailand were maintained in the laboratory over several generations to test methods to infect these ticks with Rickettsia conorii, the agent of Mediterranean spotted fever. Three methods were tested: (1) infection of adults and nymphs through artificially induced bacteremic rabbit, (2) capillary feeding of solution containing 5 x 10(3) and 5 x 10(5)pfu/mL of R. conorii to adult female ticks, and (3) immersion of engorged nymphs which were "one leg-cut," "two leg-cut," or "cuticle cut" in solution containing R. conorii. The most efficient method to infect adult ticks with R. conorii was infection of ticks through the bacteremic rabbit (71.4%). The best method to infect nymphs with R. conorii was immersion of "one leg-cut" engorged nymphs in solution containing R. conorii (30%). Interestingly, a high mortality of the ticks infected with R. conorii was observed regardless of the method used. The harmful effect of R. conorii on Rh. sanguineus group ticks from Thailand is discussed including the role of the geographic origin of the ticks and the difficulties to identify ticks within this group to the species level.
authors.affiliation: Unité des Rickettsies, CNRS UMR 6020 IFR 48, Faculté de Médecine, Marseille, France.
authors.forename: Koutaro
authors.initials: K
authors.lastname: Matsumoto
authors.forename: Philippe
authors.initials: P
authors.lastname: Brouqui
authors.forename: Didier
authors.initials: D
authors.lastname: Raoult
authors.forename: Philippe
authors.initials: P
authors.lastname: Parola
mesh_terms: D000818:Animals; D001096:Arachnid Vectors / Q000145:classification / Q000235:genetics / Q000382:microbiology*; D016470:Bacteremia / Q000382:microbiology / Q000635:transmission; D001483:Base Sequence; D001907:Boutonneuse Fever / Q000382:microbiology / Q000635:transmission*; D004285:Dogs; D005260:Female; D007814:Larva / Q000382:microbiology; D008297:Male; D023421:Models, Animal; D008969:Molecular Sequence Data; D018978:Molting; D009758:Nymph / Q000382:microbiology; D010802:Phylogeny; D012335:RNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000737:chemistry / Q000235:genetics; D011817:Rabbits; D048508:Rhipicephalus sanguineus / Q000145:classification / Q000235:genetics / Q000382:microbiology*; D020114:Rickettsia conorii / Q000302:isolation & purification / Q000472:pathogenicity*; D016415:Sequence Alignment
chemical_list: D012335:RNA, Ribosomal; D012336:RNA, Ribosomal, 16S; C075526:RNA, ribosomal, 12S