Premium
Isolation of a Rickettsia Related to Astrakhan Fever Rickettsia from a Patient in Chad
Author(s) -
FOURNIER PIERREEDOUARD,
XERIDAT BERNARD,
RAOULT DIDIER
Publication year - 2003
Publication title -
annals of the new york academy of sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.712
H-Index - 248
eISSN - 1749-6632
pISSN - 0077-8923
DOI - 10.1111/j.1749-6632.2003.tb07356.x
Subject(s) - spotted fever , rickettsia , biology , rickettsia conorii , rickettsiosis , 16s ribosomal rna , virology , rickettsiaceae , microbiology and biotechnology , candidatus , bacteria , genetics , virus
A bstract : We isolated a novel spotted fever group rickettsia from a patient coming back from Chad with fever and a maculopapulous rash. In Africa, only six pathogenic spotted fever group rickettsiae have been identified, R. conorii , R. africae , R. akari , R. aeschlimannii , ‘R. mongolotimonae,’ and R. felis . Our isolate was identified by PCR amplification and sequencing of the 16S rRNA (16S rDNA), citrate synthase ( glt A), and rOmpA ( omp A) encoding genes. The 16S rDNA, glt A, and omp A sequences of the isolate were found to be 99.7, 99.6, and 99.5% identical with that of Astrakhan fever rickettsia, respectively. This rickettsia is endemic in the Caspian sea area and has also recently been identified in Kosovo. Using mouse serotyping, the currently accepted method for the identification of spotted fever group rickettsiae, the Chad isolate exhibited a specificity difference of 2 when compared to Astrakhan fever rickettsia and at least 4 when compared with other members of the R. conorii complex. The Chad isolate should be considered a variant of Astrakhan fever rickettsia. This is the first description of Astrakhan fever rickettsia outside Europe and the bacterium may be responsible for cases of spotted fever in Chad. Although Astrakhan fever rickettsia is transmitted by Rhipicephalus ticks in Europe, further studies are indicated to identify its vector in Africa where these ticks are also prevalent.