BACKGROUND Rickettsia africae, the etiological agent of African tick bite fever, is widely distributed in sub-Saharan Africa. Contrary to reports of its homogeneity, a localized study in Asembo, Kenya recently reported high genetic diversity. The present study aims to elucidate the extent of this heterogeneity by examining archived Rickettsia africae DNA samples collected from different eco-reg...

We developed a typing method that can differentiate 8 strains of Rickettsia prowazekii into 7 genotypes. This method can be used to type and trace the origin of R. prowazekii isolated from samples collected during epidemics after a bioterrorism attack.

Technical Appendix Figure. Distribution of Gulf Coast ticks and cases of rickettsiosis. Solid circles indicate confirmed cases of Rickettsia parkeri rickettsiosis, and open circles indicate probable cases of R. parkeri rickettsiosis noted by Paddock et al. (1) and Cragun et al. (2). A) Gray area indicates the most established distribution of Gulf Coast ticks (Amblyomma maculatum); asterisks (*)...

Rickettsia tamurae is a member of the spotted fever group rickettsiae, which was reported in 2011 to cause human infections in Japan. We report the draft genome sequence of R. tamurae strain AT-1(T), isolated from Amblyomma testudinarium ticks.

Facultative endosymbionts can benefit insect hosts in a variety of ways, including context-dependent roles, such as providing defense against pathogens. The role of some symbionts in defense may be overlooked, however, when pathogen infection is transient, sporadic, or asymptomatic. The facultative endosymbiont Rickettsia increases the fitness of the sweet potato whitefly (Bemisia tabaci) in so...

Rickettsia australis strain Phillips(T) was isolated in Queensland, Australia, in 1950. It is the tick-borne agent of Queensland tick typhus, a disease endemic in Australia. The 1.29-Mb genome sequence of this bacterium is highly similar to that of Rickettsia akari but contains two plasmids.

BACKGROUND Bacterial type IV secretion systems (T4SSs) comprise a diverse transporter family functioning in conjugation, competence, and effector molecule (DNA and/or protein) translocation. Thirteen genome sequences from Rickettsia, obligate intracellular symbionts/pathogens of a wide range of eukaryotes, have revealed a reduced T4SS relative to the Agrobacterium tumefaciens archetype (vir). H...